Revisión bibliográfica: ecografía intraparto / Review: intrapartum ultrasound

The evaluation of labor is the clinical process by which variables are analyzed in order to determine whether the patient is in labor, which by definition includes regular uterine contractions that increase in frequency and intensity, associated with dilation cervical. This is done through the anamnesis and physical examination, specifically through the evaluation of contractions and vaginal examination, the latter is intended to specify the degree of dilation, cervical effacement that the patient presents and also allows to a certain degree, establish the presentation, attitude and variety of position in which the fetus is located. From this premise, it is proposed that vaginal examination, since it is operator dependent, is not an objective evaluation, therefore, there is a need to reach consensus on the evaluation, and in order to carry it out, evaluation with ultrasound is proposed, which has as a purpose to objectify the variety of position and presentation of the fetus. Due to the above, this article aims to capture the knowledge that is currently possessed about the uses and methodology that intrapartum ultrasound presents.

A importância do exame anatomopatológico da placenta em obstetrícia e neonatologia / The importance of pathological placental examination in obstetrician and neonatology

O objetivo deste trabalho é conscientizar obstetras e pediatras da importância do exame anatomopatológico da placenta no âmbito médico-legal e na prática clínica, sistematizar a busca e o reconhecimento das placentas de análise mandatória e auxiliar na criação de protocolos internos para a sua triagem. Realizou-se revisão sistemática da literatura de artigos científicos indexados nas bases de dados SciELO, LILACS, PubMed, Bireme, entre os anos de 2000 a 2012, utilizando-se as palavras-chave: placenta, doenças placentárias, /legislação & jurisprudência, responsabilidade legal. Foram incluídos aqueles com notável qualidade metodológica e relevância clínica. Observou-se que o índice de placentas enviadas à análise ainda é muito baixo, seja por falta de conhecimento da sua aplicação e da sua importância para ajudar a esclarecer fatos inesperados ou que cursem com prejuízo do desenvolvimento da criança, ou pelo fato da maioria dos hospitais não dispor de protocolos internos e recursos que permitam a realização do exame. A grande vilã da falta de uso deste exame em benefício do paciente e dos médicos é a ausência de protocolos com as suas indicações clínicas. Para isso, foi elaborada uma lista com as principais situações que poderiam indicar a análise da placenta.

Histological features of the placenta and their relation to the gross and data from Thoroughbred mares / Achados histológicos da placenta e sua relação com seus aspectos macroscópicas e dados de éguas Puro Sangue Inglês

The placenta is a transitory organ that originates from maternal and fetal tissues, the function of which is transporting nutrients from the mother to the fetus. The aim of this study was describe the histological features of placentas in healthy Thoroughbred mares at foaling and evaluate their relation with the gross placental and data of these mares. For this study 188 Thoroughbred mares were used. It was performed clinical observation for signs of placentitis during daily health checks and ultrasonic examination monthly to assess the fetus and placenta. All of the mares that exhibited clinical signs of placentitis were treated during gestation. The parturition was assisted, the placentas were grossly evaluated and samples were collected immediately after expulsion. The following data were considered for each mare: age, gestational age, number of parturition, time for placental expulsion, umbilical-cord length, placental weight and clinical signs of placentitis. Histological evaluation of the placentas revealed extensive cytoplasmic vacuolization of the epithelial areolar cells, presence of inflammatory infiltrates and hypoplasia-atrophy of the microcotyledons. Most of the gross placental findings were consistent with the histological results. In conclusion the mares with a vacuolated placental chorionic epithelium were older and had experienced a larger number of births. Great part of the mares with inflammatory infiltrates did not showed any clinical signs of placentitis during gestation.(AU)

A placenta é um órgão transitório originado do tecido fetal e materno, com função de transportar nutrientes da mãe para o feto. O objetivo deste estudo foi descrever os achados histológicos das placentas de éguas Puro Sangue Inglês (PSI) a termo e avaliar sua relação com a macroscopia da placenta e dados dessas éguas. O estudo utilizou 188 éguas PSI. Foram realizadas observações clinicas diárias para presença de sinais clínicos de placentite e ultrassonografia mensal para avaliar saúde do feto e placenta. As éguas que apresentaram sinais clínicos de placentite durante a gestação foram tratadas. Os partos foram assistidos, as placentas avaliadas macroscopicamente e coletadas imediatamente após sua expulsão. Como dados das éguas foram considerados: idade, tempo de gestação, número de partos, tempo de eliminação da placenta, comprimento de cordão umbilical, peso da placenta e sinais clínicos de placentite. A avaliação histológica das placentas demonstrou extensiva vacuolização citoplasmática das células do epitélio coriônico das regiões areolares, presença de infiltrados inflamatórios e hipoplasia-atrofia de microcotilédones. A maior parte dos achados macroscópicos da placenta foram condizentes com os resultados de histologia. Como conclusão, a vacuolização do epitélio coriônico foi característica de éguas mais velhas e com maior número de partos. Grande parte das éguas com infiltrados inflamatórios não demonstraram sinais clínicos de placentite.(AU)

Reduced placental volume and flow in severe growth restricted fetuses

OBJECTIVES: To evaluate placental volume and vascular indices in pregnancies with severe fetal growth restriction and determine their correlations to normal reference ranges and Doppler velocimetry results of uterine and umbilical arteries. METHODS: Twenty-seven fetuses with estimated weights below the 3rd percentile for gestational age were evaluated. Placental volume and vascular indices, including vascularization, flow, and vascularization flow indices, were measured by three-dimensional ultrasound using a rotational technique and compared to a previously described nomogram. The observed-to-expected placental volume ratio for gestational age and observed-to-expected placental volume ratio for fetal weight were calculated. Placental parameters correlated with the Doppler velocimetry results of uterine and umbilical arteries. RESULTS: The mean uterine artery pulsatility index was negatively correlated with the observed-to-expected placental volume ratio for gestational age, vascularization index and vascularization flow index. The observed-to-expected placental volume ratio for gestational age and observed-to-expected placental volume ratio for fetal weight and vascularization index were significantly lower in the group with a bilateral protodiastolic notch. No placental parameter correlated with the umbilical artery pulsatility index. CONCLUSIONS: Pregnancies complicated by severe fetal growth restriction are associated with reduced placental volume and vascularization. These findings are related to changes in uterine artery Doppler velocimetry. Future studies on managing severe fetal growth restriction should focus on combined results of placental three-dimensional ultrasound and Doppler studies of uterine arteries.

Assessment of Placental Stiffness Using Acoustic Radiation Force Impulse Elastography in Pregnant Women with Fetal Anomalies

OBJECTIVE: We aimed to evaluate placental stiffness measured by acoustic radiation force impulse (ARFI) elastography in pregnant women in the second trimester with a normal fetus versus those with structural anomalies and non-structural findings. MATERIALS AND METHODS: Forty pregnant women carrying a fetus with structural anomalies diagnosed sonographically at 18-28 weeks of gestation comprised the study group. The control group consisted of 34 healthy pregnant women with a sonographically normal fetus at a similar gestational age. Placental shear wave velocity (SWV) was measured by ARFI elastography and compared between the two groups. Structural anomalies and non-structural findings were scored based on sonographic markers. Placental stiffness measurements were compared among fetus anomaly categories. Doppler parameters of umbilical and uterine arteries were compared with placental SWV measurements. RESULTS: All placental SWV measurements, including minimum SWV, maximum SWV, and mean SWV were significantly higher in the study group than the control group ([0.86 ± 0.2, 0.74 ± 0.1; p < 0.001], [1.89 ± 0.7, 1.59 ± 0.5; p = 0.04], and [1.26 ± 0.4, 1.09 ± 0.2; p = 0.01]), respectively. CONCLUSION: Placental stiffness evaluated by ARFI elastography during the second trimester in pregnant women with fetuses with congenital structural anomalies is higher than that of pregnant women with normal fetuses.

Caracterización de estadios del desarrollo embrio-fetal, vesícula coriónica y de placenta en la gata doméstica (Felis catus) mediante método ecográfico / Characterization of stages of embrio-fetal, chorionic vesicle and placenta development in the domestic cat (Felis catus) by ultrasonography

La ecografía es uno de los métodos de diagnóstico gestacional más utilizados, que permite confirmar una gestación temprana y realizar seguimientos del desarrollo embrio-fetal. En este estudio se emplearon 10 gatas gestantes, entre 10 meses a 6 años de edad, con fecha de cruza conocida. Se realizaron exámenes ecográficos seriados en los días 15 (estadio 1), 18 (estadio 2), 21 (estadio 3), 38 (estadio 4), y 45 (estadio 5) de gestación para medir parámetros biométricos. Vesícula coriónica: diámetro transversal (DTVC), diámetro longitudinal (DLVC); Placenta: grosor (GP); Feto: longitud céfalo-caudal (LCC), diámetro toraco-abdominal (DTA), diámetro cefálico (DC), tomándose un registro fotográfico de cada estadio. En el estadio 1, no se logró visualizar el embrión. En el estadio 2, el embrión se observó cercano a la pared midiendo en promedio 4,7 milímetros de LCC, el tubo endocárdico se observó funcional. En el estadio 3, se observó el cordón umbilical, pero resultó difícil distinguir los diferentes órganos, excepto el corazón, debido al movimiento causado por sus latidos. En el estadio 4, el feto adquiere movimientos, se observó órganos como el encéfalo, pulmones, el tabicamiento del corazón, diafragma, hígado, estómago, asas intestinales, vejiga y la osificación de huesos. Se observó la flexión de los miembros. En los miembros anteriores se visualizaron los dedos separados, con garras y cojinetes plantares. En el estadio 5, además de las características observadas en el estadio anterior, los riñones muestran la corteza y médula, las cámaras del corazón se visualizaron claramente. Se realizó una correlación lineal entre los parámetros biométricos estudiados y los resultados dieron valor significativo (p<0,0001) para la mayoría de éstos. Se logró caracterizar los estadios gestacionales estudiados. Siete de las diez gatas presentaron una gestación normal, mientras que una de ellas presentó en uno de sus fetos una malformación congénita y en las otras dos gatas se presentó muerte embrio-fetal.

Ultrasound is one of the most widely used methods for gestational diagnosis, allowing the detection of early pregnancy and evaluation of fetal growth and development. Ten pregnant cats (aged 10 months to-6 years) were used in this study, with known dates of mating. Serial ultrasound testings were performed on days 15th (stage 1), 18th (stage 2), 21st (stage 3), 38th (stage 4) and 45th (stage 5) of gestation, to measure biometric parameters (Chorionic vesicle: transverse diameter (DTVC), longitudinal diameter (DLVC); Placenta: thickness (GP); Fetus: cephalocaudal length (LCC), thoraco-abdominal diameter (DTA), cephalic diameter (DC). Photographic records were made at each stage. In stage 1, it was impossible to visualize the embryo. In stage 2, the embryo was observed near the wall measuring 4.7 mm on average LCC, and the endocardial tube was functioning. In stage 3, the umbilical cord was observed, but it was difficult to distinguish different organs, with the exception of the heart, which was detected by heartbeat movements. In stage 4, the fetus begins to move. Organs, such as the brain, lungs, heart septation, diaphragm, liver, stomach, bowel, bladder and bone ossification were observed. In the forelimbs, fingers apart with claws and footpads were visualized. In stage 5, in addition to the features observed in the previous stage, the kidneys show the cortex and medulla, and the heart chambers are clearly visualize. A linear correlation analysis among the biometric parameters was performed. Results were statistically significant for most parameters studied (p<0.0001). We characterized the gestational stages studied. Out of the ten cats studied, seven cats had a normal pregnancy. One cat showed one congenitally malformed fetus, and one fetal death occurred in the other two cats.

Influence of maternal anemia on placental volume with study of uterine artery doppler

To study the influence of maternal hematocrit [Ht] and hemoglobin [Hb] level on placental volume with study of uterine artery Doppler. In this prospective study 40 pregnant [singleton pregnancy] cases were selected from the outpatient clinic of Alzahra university Hospital. They were divided into two groups the study group [20 cases] were anemic[iron deficiency] and the control group[20cases] were healthy. For each case two scans for the placenta and fetal growth were performed, the first at recruitment and the second 5 weeks later. Placenta volume was measured at each visit using three dimensional ultrasound. The maternal Hb and [Ht] were measured in each visit. It revealed a non statistical significance between maternal hemoglobin, hematocrit and placental volume during the 1[st] visit and 2[nd] visit in anemic group compared to the control group. As regards Doppler study of the uterine artery in the present study it was noted that the pulsatility index and resistance index showed a non significant increase in the anemic group compared to the control group. Maternal iron deficiency anemia can affect placental growth and development. Placental volume increased with mild anemia during the first trimester but has no significant effect of fetal growth. The use of 3D ultrasound is more accurate and efficient safe technique of great value in evaluating placental growth and volume. Also, the study of uterine artery blood flow during the mid second trimester showed a non significant increase of RI and PI with maternal anemia. Further study are needed for the effect of anemia on fetal growth during preconceptional, first, second, third trimester and the outcome of pregnancy

Alternate parameter for estimation of gestational age - a study

The placental thickness was estimated in about 608 normal antenatal women of all gestational ages [greater than 10 weeks] attending both Obstetrics and Radiology departments using the 3.5 Mhz USG probe. The placental measurement was taken at the insertion of the umbilical cord in all the cases. Mean placental thickness was calculated with standard deviation in all the cases. It was concluded, that the placental thickness gradually increased from 12 mm at 11 weeks to 40 mm in 39-40 weeks of gestation more or less corresponding to the gestational weeks. Between the 22nd and 40th weeks, it was corresponding to the period of gestation. In all these cases, other parameters were also taken. Thus the placental thickness can be used as an important parameter along with other parameters in early, mid and late mid trimesters where the exact duration of pregnancy is not known

Prediction of low birth weight infants from ultrasound measurement of placental diameter and placental thickness.

The aim of the study was to help to predict low birth weight infants by measuring placental diameter and thickness. Subjects and A prospective study was conducted of 70 consecutive singleton pregnancies to evaluate placental diameter and thickness by ultrasonographic measurement at 36 weeks gestation. The individual data were fitted to a logistic regression analysis. A "warning limit" of a placental diameter of 18 cm and placental thickness of 2 cm at 36 weeks gestation were calculated to predict low birth weight infants. Ultrasonographic placental diameter and thickness measurements appears to be of prognostic value in identifying the subsequent occurrence of fetal growth retardation

Doppler technique for assessing utero placental haemodynamic changes during extradural anaesthesia for elective caesarean section with pre-eclampsia

Blood flow velocity wave forms were recorded in 2 sites in the fetal circulation in a series of 20 normal and 20 complicated pregnancies with mild and severe preeclampsia before and during cesarean section [CS] under extradural [epidural] anesthesia with plain bupivacaine 0.5% as a single bolus dose after a preload of one liter of Ringer's lactate. Abnormality of the wave form reflected a high resistance to flow and high values for S/D ratio due to decreased end diastolic velocity recorded in the studied group, which proved to be useful predictor for perinatal morbidity. A significant and highly significant decrease of S/D ratio values during extradural anesthesia in the mild and severe preeclamptic patients, respectively, was an important prognostic finding in pregnancies complicated with preeclampsia. After extradural block the mean maternal blood pressure fell significantly in mild preeclamptic patients with further significant decrease in severe preeclamptic cases, but no maternal hypotension was observed

The relationship of sonographic placental grading, biochemical pulmonary maturity and neonatal outcome in pregnancy-induced hypertension.

In a prospective study, the accuracy of placental grade in predicting pulmonary maturity was evaluated in 50 cases of pregnancy-induced hypertension (PIH) between 28 and 41 weeks of gestation. Pulmonary maturity was measured by lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol (PG) in amniotic fluid and by clinical development of respiratory distress syndrome (RDS) in the neonates. Fifty normotensive healthy primigravidae, who were matched for age and period of gestation, served as control. No difference (p > 0.05) in the placental grading was observed between normotensive and hypertensive pregnancies. The advancement of placental grade was found to be associated with an increase in L/S ratio and PG level in amniotic fluid. A mature placental grade (grade III) identified by real-time sonography corresponded to foetal lung maturity (L/S > or = 2.0, PG > or = 0.36 mg/dl) and absence of RDS in all cases. Hence, in PIH a grade III placenta appeared to be a reliable predictor of foetal lung maturity in the population examined.

value of ultrasonic epiphyseal ossification centers and placental grading in the predication of fetal lung maturity in normal, preeclamptic and diabetic pregnancies

In the present study, a non-invasive method for assessment of fetal lung maturity via sonographic characterization of placental maturity and fetal epiphyseal ossification centers around the knee and shoulder was evaluated. These sonographic parameters were correlated with the amniocentesis phospholipid profile as an indicator of accuracy. They were studied in 40 normal pregnancies, 40 preeclamptic and 40 diabetic pregnancies with gestational ages ranging between 32-41 weeks. It was found that in normal pregnancies, the presence of grade 3 placenta, or DFE >/5 mm or PTE >/3 mm or the presence of PHE predicts a mature phospholipid profile in 100% of patients. However, in preeclamptic patients, the presence of grade 3 placenta is not a reliable predictor of lung maturity, but the presence of DFE >/5 mm or PTE >/3 mm or the presence of PHE has 100% positive predictive value of mature phospholipid profile. On the other hand, in diabetic pregnancies neither grade 3 placenta nor DFE >/ 5 mm are reliable indicators of fetal lung maturity. Finally, the identification of PTE >/5 mm or the presence of PHE can reliably identify a mature phospholipid profile in all studied groups with 100% accuracy. Such a perfect correlation between these epiphyseal ossification dimensions and fetal lung maturity favors the use of these selective noninvasive sonographic parameters as an alternative to invasive amniocentesis phospholipid profile in prediction of fetal lung maturity. This could save time, money, emotional investment, fetal and maternal morbidity

Study of umbilical and uterine arteries doppler velocimetry, biophysical profile, placental grading and maternal plasma fibronectin level in pre-eclampsia

The present study was conducted on 30 preeclamptic patients and 20 well matched normotensive pregnant women. All studied cases were subjected to the study of umbilical and uterine arteries Doppler velocimetry, biophysical profile, placental grading, and maternal plasma fibronectin estimation. All these studied parameters with exception of placental grading, showed abnormal findings in pre- eclampsia. The umbilical artery Doppler velocimetry, fetal biophysical profile and maternal plasma fibronectin levels were significantly correlated with the severity of preeclampsia. The correlation between the different studied parameters and fetal outcome using Apgar scoring has been evaluated where fetal biophysical scoring proved to have the best accuracy. No significant results could be detected between the studied groups concerning placental grading and uterine artery velocimetry

Accuracy of ultrasonographic criteria for the prenatal diagnosis of placental amnionicity and chorionicity in twin gestations.

A total of 31 twin pregnancies were studied antenatally with ultrasound, followed up clinically, and the placentas examined to determine if, solely on the basis of prenatal sonography, an accurate assessment of amnionicity and chorionicity could be made. Sonographic features noted included number of placental sites, fetal gender, qualitative and quantitative evaluation of the dividing membrane. Documentation of two placental sites or different fetal gender confirms the presence of a dichorionic-diamniotic pregnancy. When only one placental site or similar fetal gender is demonstrated, examination of the membrane is helpful for distinguishing between dichorionic and monochorionic diamniotic gestations. A thick membrane separating the fetuses was seen in all dichorionic diamniotic pregnancies. A thin membrane was visible in 94.4 per cent of monochorionic-diamniotic pregnancies. The predictive value of a thick membrane with regard to a dichorionic-diamniotic pregnancy was 92.3 per cent and the predictive value of a thin membrane with regard to a monochorionic-diamniotic pregnancy was 100 per cent. The thickness of the membrane was measured in 13 cases. With a thickness of 2 mm used as a cutoff point, the accuracy in predicting monochorionic or dichorionic twinning was 100 per cent for both. Lack of visualization of a separating membrane suggests a monochorionic-monoamniotic pregnancy.

Quantitative assessment of placental maturity by acoustic intensity histogram

Morphologic and sonographic changes appear progressively in the placenta as it matures with the advancing gestation. Ultrasonically these changes appear as 1-4 mm echogenic densities in the chorionic plate, placental substance, basal plate and in the intercotyledonary septa. On the basis of these changes placenta is classified into 4 grades from grade 0 to grade III. Ultrasonic placental grading system is a non invasive way to indirectly predict the placental functional maturity and fetal lung maturity. There is 100% correlation of grade III placenta with mature L/S ratio, 80% with grade II and 60% with grade I placenta. Ultrasonic placenta grading is subject to interobserver variation, to minimize this variation and to increase the accuracy of acoustic intensity histograms of placenta of patients with pregnancy of 30 weeks and over have been obtained and analysed. Histogram represent echo distributing intensity of the image. Information obtained from histogram consist of total number of pixels in a specified area [T], gray scale level of shade component that is most common in the specified area [L] and number of pixels of the shade component that is most common in specified area [M]. Relationship of the computer analysis of histogram echo pattern and conventional grading of placenta are shown in this preliminary study. Computer analysis appear superior to conventional impressions obtained by sonologists. Computer analysis can further be improved by methods discussed