El embarazo gemelar monocorial desde la perspectiva de la teoría de la complejidad / Monochorionic twin pregnancy from the perspective of the theory of complexity

En la práctica, es muy frecuente asociar las gestaciones gemelares monocoriales (MC) con embarazos complejos o complicados, utilizando ambos términos en forma intercambiable. Sin embargo, no lo son; el dinamismo es protagonista en los sistemas complejos, pero no en los complicados. Para entender a la embarazada con una gestación MC como un sistema complejo, primero se desarrollarán las características principales de los embarazos MC; su placenta es una de las principales responsables de los problemas. Luego se analizará el embarazo MC desde la complejidad, identificando las características del sistema y sus complicaciones como propiedades emergentes.

In practice, it is very common to associate monochorionic (MC) twin pregnancies with complex or complicated pregnancies, using both terms interchangeably. However, these are not synonyms; dynamism is the protagonist in complex systems, but not in complicated ones. In order to understand a MC pregnancy as a complex system, it is necessary to first look into its main characteristics. The placenta is one of the main sources of problems. Then, the MC pregnancy has to be analyzed from the perspective of complexity, identifying the system characteristics and its complications as emergent properties.

Inconsistent patterns of twin growth and their relationship with obstetric adverse outcomes / 中国现代医生

@#Objective To determine different patterns of fetal growth dissonance in twin pregnancies and their predictive role in obstetric adverse outcomes.Methods The medical records of 531cases of twin-pregnancy women who underwent labor examination and delivery in our hospital from January 2014 to december 2021 were retrospectively analyzed.According to the ultrasound parameters during the prenatal examination,the inconsistencies between twins were divided into four modes:mode 1:no significant inconsistencies group(268cases),Mode 2:early progressive inconsistencies(23cases),mode 3:early inconsistencies with plinosis(91cases)and mode 4:late inconsistencies(149cases).The dynamic changes of each model and its correlation with adverse outcomes were investigated.Results Pattern 2 and Pattern 3 inconsistencies>10%(20.5 and 20.7 weeks of gestation)and>20%(27.7 and 26.3weeks of gestation)occurred at similar times.Mode 2 had the highest rate of inconsistent progression(0.92%/week),which peaked at 23.7%at 36weeks of gestation.Mode 3 progressed at a slower rate(0.49%/week),with a smaller variance after 20weeks(from 13.3%at 20weeks to 16%at 36weeks).The onset time of pattern 4 inconsistencies was>10%at 29.8weeks of gestation,and the peak inconsistencies(14.8%)were lower than pattern 2 and pattern Using mode 1(no significant inconsistency)as a reference,after adjusting for relevant covariates,mode 2 and 3 were risk factors for preterm birth and preeclampsia at 34 and 32weeks of gestation,mode 2 was a risk factor for 5-minute Apgar score<7,and mode 2,3,and 4 were risk factors for newborn birth weight<10th percentile.Conclusion According to the occurrence,development and intensity of neonatal growth dissonance,four different dissonance patterns were identified to be associated with different obstetric outcomes.These models provide more predictive information than the single point in time when measurements of fetal size are inconsistent,which is commonly used.

Prediction of preeclampsia in twin-pregnant women / 预防医学

Objective@#To construct a prediction model for preeclampsia (PE) risk in twin-pregnant women, so as to provide the basis for early screening and prevention of PE.@*Methods@#A total of 467 twin-pregnant women who underwent prenatal examination and delivered at Huzhou Maternal and Child Health Hospital were selected. Sixty cases with preeclampsia (PE) were included in the case group, and 60 women without PE were included in the control group. General information, blood biochemical indicators and uterine artery resistance index (UtA-RI) were collected. A logistic regression model was used to screen predictive factors and establish a nomogram. The Bootstrap method was performed for the internal validation; the receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis were employed to evaluate the discrimination, calibration and clinical utility of the nomogram, respectively.@*Results@#In the case group, there were 47 individuals (78.33%) aged younger than 35 years, 21 individuals (35.00%) with pre-pregnancy body mass index (BMI) of 25 kg/m2 and above, and 33 individuals (55.00%) with in vitro fertilization. In the control group, there were 57 individuals (95.00%) aged younger than 35 years, 8 individuals (13.33%) with pre-pregnancy BMI of 25 kg/m2 and above, and 39 individuals (65.00%) with natural pregnancy. Multivariable logistic regression analysis identified age, pre-pregnancy BMI, method of conception, placental growth factor (PLGF) and UtA-RI as risk prediction factors for PE in twin-pregnant women. The established nomogram had an area under the ROC curve of 0.827 (95%CI: 0.755-0.899), a sensitivity of 0.767, a specificity of 0.733, a good discrimination and calibration, and a relatively high clinical net benefit.@*Conclusion@#The nomogram established by age, pre-pregnancy BMI, method of conception, PLGF and UtA-RI has a good predictive value for the risk of PE in twin-pregnant women.

Síndrome HELLP y rotura hepática en un embarazo gemelar: presentación de un caso / HeLLP Syndrome and Hepatic Rupture in a Twin Pregnancy: A Case Report / Síndrome HeLLP e ruptura hepática em gestação gemelar: relato de caso

Introducción: el síndrome HELLP y rotura hepática es una complicación poco frecuente, especialmente en casos de embarazo gemelar. Se presenta el caso de un hematoma subcapsular hepático roto por síndrome HELLP que complicó un embarazo gemelar que requirió una cesárea de emergencia y para el manejo de la hipovolemia, el empaquetamiento hepático. Presentación del caso: mujer de 41 años, con gestación gemelar de 35 semanas, quien acudió al servicio de emergencia, por contracciones uterinas y ausencia de movimientos fetales. Ante una bradicardia severa de ambos fetos, se optó por una cesárea de urgencia. Al abrir la cavidad abdominal, se encontró hemoperitoneo y se logró extraer ambos fetos vivos. Se realizó una laparotomía media, supra e infraumbilical exploradora (poscesárea) y se halló una rotura hepática del lóbulo derecho. Se procedió a un empaquetamiento hepático con compresas y cierre temporal abdominal; entre tanto, el manejo del shock hipovolémico y la preeclampsia se continuó en la unidad de cuidados intensivos. La paciente se fue de alta en buenas condiciones a los 21 días. Conclusión: el síndrome HELLP produce complicaciones graves, como rotura hepática, que si no es tratada de forma correcta, temprana y multidisciplinaria, puede llevar a producir mortalidad materno-perinatal.

Introduction: HELLP syndrome and hepatic rupture are rare complications, especially in the case of twin pregnancy. Here, we present a case of ruptured hepatic subcapsular hematoma due to HELLP syndrome that caused complication in a twin pregnancy. This case required emergency Cesarean section and management of hypo- volemia hepatic packing. Case presentation: A 41-year-old female pregnant with twins (35 weeks) came to the emergency room for uterine contractions and absence of fetal movements. Due to severe bradycardia in both fetuses, emergency Cesarean section was performed. When the abdominal cavity was opened, hemoperitoneum was found, and both fetuses were extracted alive. A median, supra-, and infraumbilical exploratory laparotomy (post Cesarean section) was performed, and right lobe hepatic rupture was found. Subsequently, hepatic packing with compression and temporary abdominal closure was performed. Hypovolemic shock and preeclampsia was continuously managed in the intensive care unit. At 21 days, the patient was discharged in good condition. Conclusion: HELLP syndrome causes serious complications, such as hepatic rupture, which may lead to maternal and perinatal mortality if not correctly treated early in a multidisciplinary manner.

Introdução: a síndrome HELLP e a ruptura hepática são complicações raras, especialmente em casos de gravidez gemelar. Neste artigo, apresentamos o caso de um hematoma subcapsular hepático rompido devido à síndrome HELLP que complicou uma gravidez gemelar que exigiu uma cesariana de emergência e tamponamento hepático para o manejo da hipovolemia. Apresentação do caso: mulher, 41 anos, gestação gemelar de 35 semanas, recorre ao pronto-socorro por contrações uterinas e ausência de movimentos fetais. Devido à bradicardia grave em ambos os fetos, foi decidida uma cesariana de emergência. Ao abrir a cavidade abdominal o hemoperitônio é localizado, sendo possível extrair ambos os fetos vivos. Foi realizada laparotomia exploradora mediana, supra e infraumbilical (pós-cesariana) sendo constatada ruptura hepática do lobo direito. Foi realizado tamponamento hepático com compressas e fechamento abdominal temporário, e o manejo do choque hipovolêmico e da pré-eclâmpsia foi mantido na Unidade de Terapia Intensiva, onde a paciente recebeu alta em boas condições após 21 dias. Conclusão: a síndrome HELLP produz complicações graves como a ruptura hepática que, se não tratada de forma precoce e multidisciplinar, pode levar à mortalidade materna perinatal.

Non-Invasive Prenatal Testing:Results in 3733 Cases of Twin Pregnancy and Association With Factors Such as Age / 中国医学科学院学报

Objective To explore the clinical significance of non-invasive prenatal testing(NIPT)for fetal chromosomal abnormalities in the cases of twin pregnancy and its relationship with age and other related factors.Methods A total of 3733 women with twin pregnancy of 12-26+6 weeks who voluntarily underwent NIPT in the Ningbo Women and Children's Hospital from January 2018 to December 2022 were selected.The results of NIPT and amniocentesis were compared and all the participants were followed up.The detection rate of chromosomal abnormalities by NIPT was calculated,and its correlations with age,gestational weeks,chorionicity,and pregnancy type were analyzed.Results Among the 3733 cases,71 cases of fetal chromosome abnormality were indicated by NIPT,including 13 cases of trisomy 21,19 cases of trisomy 18,5 cases of trisomy 13,18 cases of sex chromosome abnormality,and 16 cases of chromosome microdeletion/duplication(excluding 21,18,13,and sex chromosomes),among which 34 cases were true positive and 37 cases were false positive.The overall sensitivity,specificity,and positive predictive value(PPV)of NIPT for chromosomal abnormalities in the cases of twin pregnancy were 100%,98.99%,and 47.89%(34/71),respectively.NIPT showed the sensitivity,specificity,and PPV of 100%,99.78%,and 78.38%(29/37)for trisomy 21,18,and 13,100%,99.56%,and 16.67%(3/18)for sex chromosome abnormalities,and 100%,99.62%,and 12.5%(2/16)for chromosome microdeletion/duplication,respectively.In the age group of ≥40 years,the NIPT for chromosomal abnormalities showed the PPV of 66.67%,the sensitivity of 100%,and the misdiagnosis rate of 30%。However,the NIPT for trisomy 21,18,and 13 showed the PPV of 100%,the misdiagnosis rate of 0,and the sensitivity and specificity of 100%.In terms of grouping based on gestational weeks,the NIPT for chromosomal abnormalities showed the highest PPV(51.28%)in the women with twin pregnancy for 14-17+6 weeks,followed by that(50.00%)in the women with twin pregnancy for 22-26+6 weeks;the NIPT for trisomy 21,18,and 13 showed the highest PPV of 94.74% in the gestation group of 14-17+6 weeks,followed by that(83.33%)in the gestation group of 18-21+6 weeks.The rate of dichorionic diamniotic twins was higher in assisted pregnancies than in natural pregnancies,and NIPT showed the same detection efficiency for dichorionic diamniotic twins and monochorionic diamniotic twins and the same detection efficiency for different pregnancy types.Conclusions NIPT has high accuracy in the diagnosis of twin pregnancy and high sensitivity and high specificity for different ages and gestational weeks,especially for trisomy 21,18,and 13.NIPT is suitable for assisted pregnancy and natural pregnancy,and it is of high value in clinical application.However,extensive application needs a large population-based study.

Biometry and pathological ultrasound findings in multiple pregnancies / Características ecográficas y hallazgos patológicos en embarazos múltiples

Resumo Objectives: to determine the prevalence of pathological findings according to the type of chorionicity in pregnancies in two institutions in Bogotá, Colombia. Methods: descriptive, retrospective, cohort study. Biometric variables were calculated, and pathological findings were evaluated according to the type of chorionicity in multiple pregnancies. Statistical characterization was performed with absolute frequencies, calculation of relative frequencies in qualitative variables, standard deviation measures, median and interquartile range. In addition, a descriptive analysis of the information was carried out. Results: 528 studies were carried out in 141 pregnant women, 98.5% (n = 139) twins and 1.4% (n = 2) triplets. A prevalence of 35.4% of fetal complications was calculated. The most frequent was fetal growth restriction (p=0.37). According to each type of chorionicity, fetal growth restriction was presented in 50% (1/2) of the trichorionics, 16.6% (7/42) of the monochorionics, and 11.3% (11/97) of the dichorionics. Conclusion: fetal growth restriction was the most common finding, both in trichorionics, monochorionics and dichorionics pregnancies.

Resumen Objetivos: el objetivo del estudio fue determinar la prevalencia de los hallazgos patológicos ecográficos en embarazos múltiples de acuerdo con la corionicidad en dos instituciones en Bogotá-Colombia. Métodos: estudio de cohorte, descriptivo, retrospectivo. Las variables biométricas realizadas y los hallazgos patológicos se evaluaron de acuerdo con el tipo de embarazo gemelar. Se realizó caracterización estadística con frecuencias absolutas, cálculo de frecuencias relativas en variables cualitativas, medidas de desviación estándar, mediana y rango intercuartílico. Además, se realizó análisis descriptivo de la información. Resultados: se realizaron 528 estudios en 141 gestantes, encontrando 98,5% (n=139) gemelares y 1,4% (n=2) triples. Se calculó una prevalencia de 35,4% de complicaciones fetales siendo más frecuente la restricción del crecimiento fetal (p=0,37). Según la corionicidad, esta complicación se presentó en 50% (1/2) de los tricoriónicos, 16,6% (7/42) de los monocoriónicos y 11,3% (11/97) de los dicoriónicos. Conclusión: la restricción del crecimiento fetal fue el hallazgo más común en los embarazos múltiples en la población estudiada.

Characteristics of the oral glucose tolerance test in women with different pre-pregnancy body mass index and the effect of gestational diabetes mellitus on twin pregnancy outcomes

Abstract Objective This study aimed to investigate the mid-pregnancy blood glucose levels of women with singleton or twin pregnancies. Method The relationship between blood glucose levels and Gestational Diabetes Mellitus (GDM) was studied in women with different pre-pregnancy Body Mass Index (BMI), and the effect of GDM on twin pregnancy outcomes was analyzed. Women with twin (n= 1,985) and singleton (n= 1,985) pregnancies were categorized into underweight (BMI < 18.5 kg/m2, n= 597), normal weight (BMI: 18.5-23.9 kg/m2, n= 2,575), and overweight/obese (BMI ≥ 24 kg/m2, n= 798) groups. Results The incidence of GDM was 21.01% in women with twin pregnancies. Among the women with GDM in twin pregnancies, 38.37% had at least two abnormal blood glucose levels. The incidence of these parameters increased with preconception BMI, and the incidence of twin pregnancies was higher than that of singleton pregnancies (p < 0.001). In the normal weight and overweight/obese group, the oral glucose tolerance test glucose level and incidence of GDM were higher in women with twin than singleton pregnancies (p < 0.05). For twin pregnancies, the prevalence of selective fetal growth restriction was higher and anemia was lower in the GDM group than in the non-GDM group (all p < 0.05). Conclusion Therefore, a greater emphasis should be placed on BMI before conception, and well-controlled GDM does not increase adverse pregnancy outcomes for twin pregnancies.

A Study on the Correlation between Preeclampsia and Carbon Metabolism in Dichorionic Diamniotic Twin Pregnancy / 实用妇产科杂志

Objective:To explore the correlation between choline,betaine,dimethylglycine,methionine and tri-methylamine oxide,metabolites related to the methionine cycle in carbon metabolism,and preeclampsia(PE)in di-chorionic diamniotic(DCDA)twin pregnancy.Methods:175 pregnant women with twin pregnancies who under-went regular prenatal examinations were registered in Peking University Third Hospital from July 2017 to April 2019 were included as the study subjects.According to whether PE had occurred,they were divided into non-PE group(138 cases)and PE group(37 cases).The fasting peripheral blood of pregnant women during the second trimester of pregnancy was collected,and the metabolites were quantitatively analyzed by ultra-high performance liquid chromatogrey-triple quadrupole tandem mass spectrometry(UHPLC-QqQ MS).The basic characteristics and plasma metabolite concentrations were compared between PE group and non-PE group.Poisson regression was used for plasma metabolite-related PE relative risk(RR)analysis,and receiver operating characteristic(ROC)curve was used to evaluate the accuracy of PE model prediction.Results:①Compared with the non-PE group,the rate of elderly pregnant women was higher,the concentration of betaine was lower,and the concentra-tion of choline was higher in PE group.The differences were statistically significant(P＜0.05).②Poisson regres-sion analysis showed that in the model adjusted for all confounding factors,there was a positive correlation be-tween maternal choline levels and PE risk(RR＞1,P＜0.05).The risk of PE occurrence increased as the in-crease of choline levels(Ptrend＜0.05).Betaine levels were negatively associated with PE risk(RR＜1,P＜0.05).The risk of PE occurrence decreased as the increase of betaine level(Ptrend＜0.05).There was no corre-lation between plasma levels of dimethylglycine,methionine and trimethylamine oxide and the risk of PE.③Pois-son regression analysis showed that the relative risk of PE was lowest when the plasma betaine/choline ratio was highest(RR0.32,95％Cl 0.14-0.75).When the dimethylglycine/betaine ratio was in the thirdpercentile,the risk of PE was increased in pregnant women(RR 2.53,95％Cl 1.01-6.32).(4)ln terms of PE prediction,the AUC combined with general risk factors and methionine metabolites was 0.80.Conclusions:Maternal choline and be-taine levels in the second trimester are related to the occurrence of PE in DCDA twin pregnancy,and provide a new idea for early prediction and intervention of PE.It is still necessary to expand the sample size to further verify and explore the mechanism.

Embarazo gemelar espontáneo en útero bicorpóreo: una contribución a la experiencia / Spontaneous twin pregnancy in a bicorporeal uterus, a contribution to the experience

Resumen ANTECEDENTES: Las anomalías uterinas congénitas son consecuencia de la formación anormal, fusión o reabsorción de los conductos de Müller durante el desarrollo embriológico. El útero bicorne, unicorne y didelfo (U1, U2, U3 ESHRE-ESGE) son defectos en la unificación con una baja prevalencia en la población general y en la que tiene antecedente de aborto e infertilidad; se estima en alrededor de 0.4 a 1.1%, respectivamente. La presentación del caso puede aportar información útil relacionada con la evolución del embarazo y los desenlaces perinatales cuando aparece esta anomalía. CASO CLÍNICO: Paciente de 35 años, con amenorrea secundaria y prueba inmunológica de embarazo positiva, con antecedentes de dismenorrea primaria severa y anomalía uterina congénita compatible con útero bicorpóreo (U3 completo ESHRE-ESGE), bicorne completo (4a-AFS) y didelfo. El embarazo trascurrió sin complicaciones hasta la semana 37, cuando finalizó mediante cesárea, con hipotonía uterina que no ameritó transfusión de hemoderivados. CONCLUSIÓN: Los embarazos gemelares con útero bicorne son excepcionales y casi todos se logran espontáneamente; los que llegan a término finalizan mediante cesárea electiva.

Abstract BACKGROUND: Congenital uterine anomalies are the result of abnormal formation, fusion, or resorption of the Müllerian ducts during embryological development. The bicornuate, unicornuate and didelphic uterus (U1, U2, U3 ESHRE/ESGE), are unification defects with a low prevalence both in the general population and in the population with a history of abortion and infertility, is estimated at around 0.4 to 1.1%, respectively. The presentation of the case can provide useful information related to with the evolution of the pregnancy and the perinatal outcomes when this anomaly appears. CLINICAL CASE: A 35-year-old patient with secondary amenorrhea and a positive immunological pregnancy test with a history of severe primary dysmenorrhea and previous magnetic resonance imaging with a congenital uterine anomaly compatible with a bicorporeal uterus (U3 complete ESHRE-ESGE), complete bicornuate (4a /AFS) , uterus didelphys (ASRM). The pregnancy was uncomplicated until 37 weeks, when it was terminated by cesarean section, with uterine hypotonia that did not require transfusion of blood products. CONCLUSION: Twin pregnancy with bicornuate uterus is a rare entity, most of them have been achieved spontaneously and those that reach term have been resolved by elective cesarean section.

HPLC-MS/MS method for determination of betamethasone in human plasma with application to a dichorionic twin pregnancy pharmacokinetic and placental transfers studies

Abstract Betamethasone (BET) is a synthetic glucocorticoid recommended for pregnant women at imminent risk of preterm birth before 34 weeks to reduce neonatal complications. There are different techniques to describe BET plasma quantification. However, none quantified the plasmatic concentration of BET in dichorionic (DC) twin pregnancies using LC-MS. Our objectives were to develop and validate a method for quantifying BET by LC-MS for pharmacokinetic (PK) and placental transfer studies in DC twin pregnancies. Blood samples were collected after intramuscular administration of a single BET dose containing 6 mg disodium phosphate + 6 mg acetate. BET was determined in plasma by liquid-liquid extraction. The method showed linearity in the range of 2-250 ng/mL, as well as precision and accuracy with a coefficient of variation and relative standard errors ≤ 15%. Additionally, the method presented selectivity and did not present matrix or carry-over effect. Stability tests also presented coefficient of variation and relative standard errors ≤ 15%. This is the first study which describe maternal and fetal plasma concentrations of BET in a DC twin pregnancy. The BET PK parameters were AUC0-∞, CL/F, Vd/F, Cmax, Tmax of 292.20 h*ng/mL, 39.08 L/h, 278.72 L, 25.55 ng/mL and 0.58 h, respectively. The placental transfer ratios of umbilical vein/maternal vein and intervillous space/maternal vein were 0.14 and 0.19 and 0.40 and 0.27 for both twins, respectively. However, a clinical study with more subjects is imperative to confirm this higher concentration of BET in the intervillous space

Útero bicorporeo - doble cérvix con embarazo gemelar en una sola cavidad uterina: reporte de caso / Bicorporeo uterus - double cervix with twin pregnancy in a single uterine cavity: case report

El embarazo gemelar en una de las cavidades uterinas del útero bicorpóreo es una rara presentación clínica. La viabilidad de este tipo de embarazo es de baja probabilidad, dado que esta malformación puede condicionar parto prematuro, placentación anormal, restricción del crecimiento fetal o progresión anormal del trabajo de parto. Se presenta un caso de un útero bicorpóreo con doble cérvix y una gestación gemelar en unas de las cavidades uterinas, con muerte fetal de uno de los fetos y parto pretérmino de 28 semanas del otro gemelo. Dada la rareza de la presentación se describen el caso y los hallazgos imagenológicos representativos.

Twin pregnancy in one of the uterine cavities of the bicoporous uterus is a rare clinical presentation. The viability of this type of pregnancy is unlikely since this malformation can lead to premature delivery, abnormal placentation, fetal growth restriction or abnormal progression of labor. We present a case of bicoporous uterus with double cervix with twin pregnancy in one of the uterine cavities, with stillbirth of one of the fetuses and preterm delivery of the other twin at 28 weeks. Given the rarity of the presentation, the case and representative imaging findings are described.

Anastomosis placentarias en embarazos gemelares monocoriales: estudio mediante técnicas de inyección vascular y relación con complicaciones fetales / Placental anastomoses in monochorionic twin pregnancies: study using vascular injection techniques and relationship with fetal complications

RESUMEN Introducción. Los embarazos gemelares son clasificados en dos grupos: monocoriónico (MC) y dicoriónico (DC). Los gemelos MC tienen 5 a 6 veces más riesgo de tener un resultado perinatal adverso. Se publica el estudio de un grupo de 22 placentas de pacientes con embarazo gemelar monocoriónico que presentaron complicaciones como síndrome de transfusión feto-fetal (STFF), secuencia de anemia policitemia (TAPS), perfusión arterial reversa (TRAP) y restricción de crecimiento intrauterino selectivo (RCIU-s). Objetivo . Determinar los tipos de anastomosis predominantes en las placentas con síndrome de transfusión feto-fetal, secuencia de anemia policitemia, síndrome de perfusión arterial reversa y restricción de crecimiento selectivo. Metodología . Se aplicó la técnica de inyección vascular placentaria para el reconocimiento de las anastomosis. Resultados . El número medio de anastomosis por placenta en el STFF (que fue la complicación más severa) fue de 8,2 ± 2,2. Las anastomosis AV y VA predominaron en un 83%. Hubo signos de discordancia placentaria en 30% de las placentas, y un 40% de placentas presentaron cordón de inserción velamentosa. Conclusiones. Las anastomosis vasculares no solo están implicadas en la etiología de las principales patologías propias de gestaciones monocoriónicas, sino que también influyen en su manejo. Creemos que un adecuado estudio placentario de cada uno de estos casos mediante la técnica de inyección vascular placentaria sería indispensable en los centros que aspiran a desarrollar manejos diferenciados de terapia fetal para cada una de estas complicaciones.

ABSTRACT Introduction: Twin pregnancies are classified into two groups: monochorionic (MC) and dichorionic (DC). MC twins are 5 to 6 times more likely to have an adverse perinatal outcome. The study of a group of 22 placentas from patients with monochorionic twin pregnancy who presented with complications such as feto-fetal transfusion syndrome (FFTS), twin anemia polycythemia sequence (TAPS), twin reverse arterial perfusion syndrome (TRAP) and selective intrauterine growth restriction (sIUGR) is presented. Objective: To determine the predominant types of anastomoses in placentas with feto-fetal transfusion syndrome, twin anemia polycythemia sequence, reverse arterial perfusion syndrome and selective intrauterine growth restriction. Methodology: The placental injection technique was applied for the recognition of anastomoses. Results: The mean number of anastomoses per placenta in STFF, which was the most severe complication, was 8.2 ± 2.2. The AV and VA anastomoses predominated in 83%. There were signs of placental discordance in 30% of placentas, and 40% of placentas presented velamentous cord insertion. Conclusions: Vascular anastomoses are not only involved in the etiology of the main pathologies of monochorionic gestations, but also influence their management. We believe that an adequate placental study of each of these cases by means of the placental vascular injection technique would be essential in centers that aspire to develop differentiated fetal management for each of these complications.

Applicability of the Institute of Medicine recommendations of gestational weight gain in women with twin pregnancies in Chengdu city / 中华健康管理学杂志

Objective:To analyze the applicability of the Institute of Medicine (IOM) recommendations of gestational weight gain (GWG) in women with twin pregnancies in Chengdu city.Methods:A total of 1 862 women delivering live twins ≥28 weeks of gestation at all midwifery institutions in Chengdu city from January 2013 to December 2019 were selected, and the women were divided into low GWG group (880 women), adequate GWG group (839 women) and excessive GWG group (143 women) according to the IOM recommendations of GWG. Information of the subjects was extracted from Chengdu “One-Card” Maternal and Child Health Information System. Chi-square test and analysis of variance were used to compare the basic information, pregnancy complications and perinatal adverse outcomes among the three groups. Multivariate logistic regression was used to analyze the relationship between GWG and pregnancy complications or perinatal adverse outcomes.Results:Of the women, 72.8% (611/1 862) had normal weight before pregnancy. The weight gain of low, adequate and excessive GWG groups was (11.8±3.4) kg, (18.8±2.6) kg and (26.1±2.9) kg, respectively. The incidence of low birthweight was highest in the low GWG group (71.0%), it was lowest in the excessive GWG group (51.0%), and it was 61.3% in the adequate GWG group ( P<0.001). There was no significant difference in gestational hypertension, gestational diabetes mellitus, premature rupture of membranes, very low birthweight, preterm birth, very premature birth, 5-minute Apgar score<7 and neonatal death within 7 days postpartum among the three groups (all P>0.05). The multivariable logistic regression analysis showed that, compared with women inadequate GWG group, those from the low GWG group tended to deliver infants with low birthweight ( OR=1.62, 95% CI: 1.32-2.00), whereas women from the excessive GWG group were less likely to deliver low birthweight infants ( OR=0.63, 95% CI: 0.44-0.91) (both P<0.05). Conclusion:The IOM recommendations for gestational weight gain are valuable in improving the pregnancy complications and perinatal outcomes of twin pregnancies in Chengdu city to certain extent, especially in improving the low birthweight of newborns.

Investigation on the incidence and risk factors of fetomaternal hemorrhage syndrome in pregnant women in Changsha / 中国输血杂志

【Objective】 To investigate the incidence and possible risk factors of FMH among pregnant women in Changsha. 【Methods】 A total of pregnant women (6~42 weeks of gestation) who underwent prenatal examinations in our hospital from June 2019 to December 2020 were enrolled as subjects. In this study, the modified Kleihauer-Betke (K-B) test was used for preliminary screening and flow cytometry was applied to confirme initially positive samples to evaluate the incidence of FMH and estimate fetal blood loss. The logistic regression analysis was used to study the risk factors of FMH. 【Results】 The incidence of FMH in pregnant women was 10.45% (183/1 752), the average volume of fetal blood loss was (2.50±3.87)mL, and 0.11% (2/1 752) of the fetal losed blood > 30 mL. Univariate analysis showed that age, twin pregnancy, pregnancy complicated with uterine fibroids, in vitro fertilization, fetal growth restriction, preeclampsia, and number of pregnancies may be risk factors for FMH. Multivariate analysis showed that twin pregnancy (OR 2.274, 95%CI: 1.135-4.458, P<0.05) and preeclampsia (OR 2.341, 95%CI: 1.082-4.837, P<0.05) were independent risk factors for FMH. 【Conclusion】 Maternal age and various physiological and pathological factors during pregnancy may be associated with the risk of FMH, especially twin pregnancy and pre-eclampsia are independent risk factors for FMH.

Clinical analysis on the influencing factors related to preterm twin pregnancy

SUMMARY OBJECTIVE: The aim of this study was to explore the influencing factors of preterm twin pregnancy. METHODS: In total, 602 twin-pregnant women delivered from February 2016 to February 2020 were analyzed retrospectively. According to whether the pregnant women were preterm or not, they were divided into preterm group (n=363) and term group (n=239). Baseline information, such as maternal age, address, and education level of the pregnant women, were collected. The clinical information of pregnant women, such as chorionic, preeclampsia, gestational diabetes, premature rupture of membranes, abnormal fetal position, and fetal weight, were analyzed. Logistic regression analysis was used to analyze the risk factors. p-value <0.05 was considered statistically significant. RESULTS: In the preterm group, monochorionic diamniotic comorbidities were significantly higher compared with the control group (p<0.05). Higher risks of preterm group have lower education (p<0.05). Multiple logistic regression analysis demonstrated that education, preeclampsia, and premature rupture of membranes were risk factors for preterm twin pregnancy. CONCLUSIONS: Preterm birth in twin pregnancy is associated with many risk factors, such as education, preeclampsia, and premature rupture of membranes. Pregnancy supervision and prenatal guidance for twin pregnancy should be strengthened. Furthermore, early detection and diagnosis of comorbidities can improve maternal and neonatal outcomes.

Value of fetal ultrasonography index in twin fetal heart malformation screening at 11-13 + 6 weeks of gestation / 中华超声影像学杂志

Objective:To investigate the clinical value of fetal ultrasonography in the screening of congenital heart malformations in twins at 11-13 + 6 weeks of gestation. Methods:A retrospective cohort study method was used.Cases were collected from Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital (January 2012 to December 2016) and the Fourth Hospital of Shijiazhuang City (January 2014 to December 2018). The twins with singleton or twins with cardiac malformation were screened out as the cardiac malformation group, and the twins with normal delivery during the same period were selected as the control group. Ultrasound data such as the nuchal translucency (NT), crown-rump-length (CRL), chorionicity, conception method, NT discordance, CRL discordance, NT discordance ≥20% incidence rate between twins, and the CRL discordance ≥10% incidence rate between twins in the two groups at 11-13 + 6 weeks were compared and analyzed. Results:①There were 30 cases in the cardiac malformation group (including 27 twins with singleton cardiac malformation and 3 twins with twin cardiac malformation) and 1 906 cases in the control group. ②The incidence rates of NT value ≥95th percentile and NT value ≥99th percentile in one or two pregnancies were significantly higher in the cardiac malformation group than in the control group (20.00% vs 2.20%, P<0.001; 10.00% vs 0.63%, P=0.002), the area under the ROC curve (AUC) for cardiac malformation screening was 0.589 and 0.549, respectively; CRL discordance in cardiac malformation group was higher than that in control group ( P=0.018), the incidence of CRL discordance ≥10% in the cardiac malformation group was higher than that in the control group (26.67% vs 12.70%, P=0.024), the AUC of cardiac malformation screening was 0.570; there were no significant differences in the incidence of NT discordance, the incidence of NT discordance ≥20%, pregnancy pattern and chorionicity between the two groups (all P>0.05). ③Multivariate Logistic regression analysis was performed using the incidence rates of NT value ≥95% and NT value ≥99%, CRL discordance ≥10%, and NT discordance ≥20%. The incidences of fetal NT value ≥95% and NT value ≥99% were risk factors for cardiac malformation in twins ( OR=11.095, 105.778; 95% CI=4.311-28.558, 16.984-658.796). Conclusions:Ultrasound at 11-13 + 6 weeks of gestation showing thickened value of one or two fetuses, and the CRL discordance≥10%, indicates an increased risk of cardiac malformation in the twins; NT value ≥95% and NT value ≥99% is a risk factor for heart defects in twins.

Effects of gestational weight on the association between serum high sensitivity C reaction protein and gestational diabetes mellitus among twin gestations: A cohort study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the association between serum high sensitivity C-reaction protein (hsCRP) in early pregnancy and gestational diabetes mellitus (GDM) among twin pregnant women, and to explore the effects of the pre-pregnant body mass index (BMI) and gestational weight gain (GWG) status on such association.@*METHODS@#Twin pregnant women with pre-pregnant BMI greater than or equal to 18.5 kg/m2 were recruited at Department of Obstetrics and Gynecology of Peking University Third Hospital from March 2017 to December 2020. Serum samples collected in early pregnancy were analyzed for hsCRP using particle-enhanced immunoturbidimetric method. In the following visits, the information about GWG and GDM were prospectively collected in every trimester. The association effect between hsCRP tertiles and GDM were estimated using Logistic regression, and further converted into risk ratio (RR). Cochran-Mantel-Haenszel test and mediation analysis were used to explore the effects of BMI and GWG status on the association.@*RESULTS@#Among the included 570 twin pregnant women, 31.6% deve-loped GDM, 26.1% were pre-pregnant overweight or obesity, and 49.5% with GWG out of referenced range. After adjustment for confounding factors, risk of developing GDM in twin gestations with the middle tertile and highest tertile of serum hsCRP in early pregnancy were 1.42 fold (95%CI: 1.02-1.89) and 1.54 fold (95%CI: 1.12-2.02), respectively, compared with the lowest tertile of serum hsCRP, and there existed significantly linear trend (P=0.022). Findings from mediation analysis illustrated that pre-pregnant BMI had partial mediating effect on the association, and BMI accounted for 23.84% (P < 0.001) of the increasing GDM risks with elevated hsCRP. Joint analysis with hsCRP and GWG found that those who were with GWG out of referenced range accompanied with the higher hsCRP tertiles (>1.21 mg/L) had significantly 2.31 fold increased risk according to those who were with GWG in the referenced range accompanied with the lowest hsCRP tertile (≤1.21 mg/L, P < 0.01).@*CONCLUSION@#Elevated hsCRP in early pregnancy significantly increased GDM risk among twin pregnant women. The hsCRP-GDM association was dependent on GWG status, and pre-pregnant BMI had partial mediating effect on such association. It is suggested that twin pregnant women should consider systemic inflammation and gestational weight at the same time to reduce GDM risk.

Bases informacionales para el estudio morfométrico de placentas en embarazos gemelares

RESUMEN Introducción: En Cuba existen muy pocos estudios morfofuncionales de placentas procedentes de embarazos gemelares que permitan establecer un patrón morfométrico general. Implementar estas bases informacionales contribuiría a perfeccionar las acciones del Programa Nacional de Salud Sexual y Reproductiva en el país. Objetivo: Sistematizar información sobre estudios morfométricos en placentas gemelares para construir la base epistémica de la caracterización del patrón morfométrico de las placentas gemelares y su relación con la corionicidad, la función de este órgano y el grado de bienestar fetal y neonatal. Método: Se aplicó una estrategia de búsqueda en el período enero de 2020 hasta abril de 2021, en bases de datos internacionales (Medline, EMBASE, LILACS, Scopus, Google Académico) para la revisión bibliográfica, mediante la utilización del método de análisis y crítica de las fuentes desde el procedimiento de análisis de contenido. Se empleó un algoritmo para la toma de decisiones en torno a la pertinencia, actualidad novedad y aportes. Resultados: Se hallaron 16 fuentes bibliográficas sobre el tema de investigación, entre ellas: solo una tesis (6,25 %) y 4 textos editados (25 %). Predominaron los artículos científicos (68,75 %) de los últimos cinco años (93,75 %). Todas las fuentes contribuyeron a la construcción de los referentes teóricos. Conclusiones: El estudio morfométrico de la placenta en embarazos gemelares es un área insuficientemente desarrollada en el conocimiento de las ciencias básicas biomédicas, dada la escasa producción bibliográfica sobre el tema.

ABSTRACT Introduction: In Cuba there are very few morphofunctional studies of placentas from twin pregnancies that allow establishing a general morphometric pattern. Implementing these informational databases would help to improve the actions of the National Sexual and Reproductive Health Program in the country. Objective: To systematize information on morphometric studies in twin placentas to build the epistemic basis for the characterization of the morphometric pattern of twin placentas and its relationship with chorionicity, the function of this organ and the degree of fetal and neonatal well-being. Method: A search strategy was applied in the period January 2020 to April 2021, in international databases (Medline, EMBASE, LILACS, Scopus, Google Scholar) for the bibliographic review, using the analysis and criticism method. of the sources from the content analysis procedure. An algorithm was used to make decisions about relevance, news, news and contributions. Results: 16 bibliographic sources were found on the research topic, among them: only one thesis (6.25%) and 4 edited texts (25.0%). Scientific articles (68.75%) from the last five years (93.75%) predominated. All the sources contributed to the construction of the theoretical referents. Conclusions: The morphometric study of the placenta in twin pregnancies is an insufficiently developed area in the knowledge of basic biomedical sciences, given the scarce bibliographic production on the subject.

RESUMO Introdução: Em Cuba existem poucos estudos morfofuncionais de placentas de gestações gemelares que permitam estabelecer um padrão morfométrico geral. A implementação desses bancos de dados informativos ajudaria a melhorar as ações do Programa Nacional de Saúde Sexual e Reprodutiva no país. Objetivo: Sistematizar informações sobre estudos morfométricos em placentas gêmeas para construir a base epistêmica para a caracterização do padrão morfométrico de placentas gêmeas e sua relação com a corionicidade, a função desse órgão e o grau de bem-estar fetal e neonatal. Método: Foi aplicada uma estratégia de busca no período de janeiro de 2020 a abril de 2021, em bases de dados internacionais (Medline, EMBASE, LILACS, Scopus, Google Scholar) para a revisão bibliográfica, utilizando o método de análise e crítica das fontes da análise de conteúdo procedimento. Um algoritmo foi usado para tomar decisões sobre relevância, notícias, notícias e contribuições. Resultados: Foram encontradas 16 fontes bibliográficas sobre o tema da pesquisa, entre elas: apenas uma tese (6,25%) e 4 textos editados (25,0%). Predominaram artigos científicos (68,75%) dos últimos cinco anos (93,75%). Todas as fontes contribuíram para a construção dos referentes teóricos. Conclusões: O estudo morfométrico da placenta em gestações gemelares é uma área pouco desenvolvida no conhecimento das ciências biomédicas básicas, dada a escassa produção bibliográfica sobre o assunto.

Importancia social del estudio morfométrico en placentas procedentes de embarazos gemelares / Social importance of the morphometric study in placentas from twin pregnancies / Importância social do estudo morfométrico em placentas de gestações gemelares

RESUMEN Se fundamenta la necesidad de la investigación científica para el estudio morfométrico en placentas procedentes de embarazos gemelares, como aproximación a la correlación entre el patrón morfométrico, la corionicidad y el bienestar fetal y neonatal, en tanto criterios básico/clínicos a tomar en cuenta para perfeccionar las acciones del programa nacional de salud sexual y reproductiva en Cuba. Se destaca la importancia social de un diseño de investigación en este campo, al constatar las carencias epistémicas desde una búsqueda sistematizada de información bibliográfica sobre el tema.

ABSTRACT The need for scientific research for the morphometric study in placentas from twin pregnancies is founded, as an approximation to the correlation between the morphometric pattern, chorionicity and fetal and neonatal well-being, as basic / clinical criteria to be taken into account to improve the actions of the national sexual and reproductive health program in Cuba. The social importance of a research design in this field is highlighted, when verifying the epistemic deficiencies from a systematized search of bibliographic information on the subject.

RESUMO Fundamenta-se a necessidade de pesquisas científicas para o estudo morfométrico em placentas de gestações gemelares, como uma aproximação da correlação entre o padrão morfométrico, corionicidade e bem-estar fetal e neonatal, como critérios básicos / clínicos a serem levados em consideração para melhorar a ações do programa nacional de saúde sexual e reprodutiva em Cuba. Ressalta-se a importância social de um desenho de pesquisa nessa área, ao verificar as deficiências epistêmicas a partir de uma busca sistematizada de informações bibliográficas sobre o assunto.

Thyroid function of first-trimester twin pregnant women and its association with preterm delivery / 北京大学学报(医学版)

OBJECTIVE@#To describe the thyroid function abnormality of first-trimester twin pregnant women according to different references, and to explore its association with preterm delivery.@*METHODS@#Participants, first-trimester twin pregnant women, were recruited at Peking University Third Hospital from March 2017 to February 2020. The thyroid hormone reference for ordinary adults identified on the assay kits by Siemens incorporation, thyroid hormone reference specifically for singleton pregnancy established previously, and thyroid hormone reference specifically for twin pregnancy established previously were used in the description of hypothyroidism and hyperthyroidism for first-trimester twin pregnant women. Thyroid autoantibody reference identified on the assay kits by Siemens incorporation was used in the description of positive thyroid autoantibody. Multivariable log-binomial regression was conducted to examine the association between thyroid function and preterm delivery, in which normal pregnant women according to the three references and normal pregnant women according to twin pregnancy reference accompanied with negative thyroid autoantibody were taken as control respectively.@*RESULTS@#A total of 570 twin pregnant women were finally included. Rates of hypothyroidism according to the three references were 1.2%, 1.6% and 3.5%, respectively. Rates of hyperthyroidism according to the three references were 32.6%, 18.1% and 1.1%, respectively. After adjustment for potential confounding factors, risk of preterm delivery significantly increased in pregnant women with hyperthyroidism according to the twin specific pregnancy reference [adjusted relative risk (ARR)=1.41, 95%CI: 1.14-1.75], while no significant increase was found in those with normal thyroid function according to the twin specific pregnancy reference but hyperthyroidism according to the singleton specific pregnancy reference (ARR=1.00, 95%CI: 0.81-1.25) and in those with hyperthyroidism purely according to the ordinary adult reference (ARR=1.06, 95%CI: 0.85-1.32), compared with those normal according to all the references. Risks of preterm delivery almost significantly or significantly increased in pregnant women with hypothyroidism according to the ordinary adult or singleton specific pregnancy reference (ARR=1.40, 95%CI: 0.88-2.22) and those with hypothyroidism according to the twin specific pregnancy reference (ARR=1.53, 95%CI: 1.03-2.28). Overall analysis of thyroid function according to the twin specific pregnancy reference and thyroid autoantibody showed that risks of preterm delivery almost significantly or significantly increased in pregnant women with simple hypothyroidism (ARR=1.46, 95%CI: 0.93-2.27), simple positive thyroid autoantibody (ARR=1.32, 95%CI: 1.15-1.52), and hypothyroidism accompanied with positive thyroid autoantibody (ARR=1.78, 95%CI: 1.30-2.44), compared with those normal according to the twin specific pregnancy reference with negative thyroid autoantibody.@*CONCLUSION@#The ordinary adult reference and that of singleton pregnancy may lead to under-diagnosis of hypothyroidism and over-diagnosis of hyperthyroidism in first-trimester twin pregnant women. Compared with pregnant women with normal thyroid function, those missed in the diagnosis of hypothyroidism were at a higher risk of preterm delivery, while those over-diagnosed as hyperthyroidism had a similar risk of preterm delivery, indicating a need to develop and generalize twin-pregnancy-specific reference on common indicators of thyroid function. Moreover, the thyroid autoantibody should be taken into consideration in the prenatal diagnosis and treatment to twin pregnant women with hypothyroidism.