Is willingness to exercise programmed in utero? Reviewing sedentary behavior and the benefits of physical activity in intrauterine growth restricted individuals / A vontade de se exercitar é programada ainda no útero? Análise do comportamento sedentário e dos benefícios da atividade física em indivíduos com crescimento intrauterino restrito

Abstract Objective: The literature suggests that a fetus will adapt to surrounding adversities by optimizing its use of energy to improve survival, ultimately leading to the programming of the individual's energy intake and expenditure. While recent reviews focused on the fetal programming of energy intake and food preferences, there is also some evidence that fetal adversity is associated with diminished physical activity levels. Therefore, we aimed to review (a) the evidence for an association between being born with intrauterine growth restriction and sedentarism over the life-course and (b) the potential benefits of physical activity over cardiometabolic risk factors for this population. Sources: PubMed, Scielo, Scopus and Embase. Summary of findings: Most clinical studies that used objective measures found no association between intrauterine growth restriction and physical activity levels, while most studies that used self-reported questionnaires revealed such relationships, particularly leisure time physical activity. Experimental studies support the existence of fetal programming of physical activity, and show that exposure to exercise during IUGR individuals' life improves metabolic outcomes but less effect was seen on muscle architecture or function. Conclusions: Alterations in muscle strength and metabolism, as well as altered aerobic performance, may predispose IUGR individuals to be spontaneously less physically active, suggesting that this population may be an important target for preventive interventions. Although very heterogeneous, the different studies allow us to infer that physical activity may have beneficial effects especially for individuals that are more vulnerable to metabolic modifications such as those with IUGR.

Resumo Objetivo: A literatura sugere que um feto se adaptará às adversidades externas ao aprimorar seu gasto energético para melhorar a sobrevida, o que leva, em última instância, à programação do consumo e gasto energético do indivíduo. Apesar de análises recentes terem focado na programação fetal do consumo energético e preferências alimentares, ainda há alguma comprovação de que as adversidades fetais estão associadas aos baixos níveis de atividade física. Portanto, visamos a analisar: a) a comprovação de uma associação entre nascer com restrição de crescimento intrauterino (RCIU) e sedentarismo durante o curso de vida e b) os possíveis benefícios da atividade física sobre os fatores de risco cardiometabólico dessa população. Fontes: PubMed, Scielo, Scopus e Embase. Resumo dos achados: A maior parte dos estudos clínicos que usaram medidas objetivas não constatou associação entre RCIU e os níveis de atividade física, ao passo que a maior parte dos estudos que usaram questionários de autorrelato revelou essas relações, principalmente no que diz respeito à atividade física de lazer. Estudos experimentais corroboram a existência de programação fetal de atividade física e mostram que a exposição a exercícios durante a vida de indivíduos com RCIU melhora os resultados metabólicos, porém menos efeito foi visto sobre a arquitetura ou função muscular. Conclusões: Alterações na força muscular e no metabolismo, bem como o desempenho aeróbico alterado, podem predispor indivíduos com RCIU a serem espontaneamente menos ativos fisicamente, sugere que essa população pode ser um importante alvo de intervenções preventivas. Apesar de muito heterogêneos, os diferentes estudos nos possibilitam deduzir que a atividade física pode ter efeitos benéficos principalmente em indivíduos mais vulneráveis a modificações metabólicas, como aqueles com RCIU.

Is willingness to exercise programmed in utero? Reviewing sedentary behavior and the benefits of physical activity in intrauterine growth restricted individuals.

OBJECTIVE: The literature suggests that a fetus will adapt to surrounding adversities by optimizing its use of energy to improve survival, ultimately leading to the programming of the individual's energy intake and expenditure. While recent reviews focused on the fetal programming of energy intake and food preferences, there is also some evidence that fetal adversity is associated with diminished physical activity levels. Therefore, we aimed to review (a) the evidence for an association between being born with intrauterine growth restriction and sedentarism over the life-course and (b) the potential benefits of physical activity over cardiometabolic risk factors for this population. SOURCES: PubMed, Scielo, Scopus and Embase. SUMMARY OF FINDINGS: Most clinical studies that used objective measures found no association between intrauterine growth restriction and physical activity levels, while most studies that used self-reported questionnaires revealed such relationships, particularly leisure time physical activity. Experimental studies support the existence of fetal programming of physical activity, and show that exposure to exercise during IUGR individuals' life improves metabolic outcomes but less effect was seen on muscle architecture or function. CONCLUSIONS: Alterations in muscle strength and metabolism, as well as altered aerobic performance, may predispose IUGR individuals to be spontaneously less physically active, suggesting that this population may be an important target for preventive interventions. Although very heterogeneous, the different studies allow us to infer that physical activity may have beneficial effects especially for individuals that are more vulnerable to metabolic modifications such as those with IUGR.

[Report from the CFEF seminar on fetal biometry (June 2017)]. / Compte rendu du séminaire de travail du Collège français d'échographie fœtal (CFEF) sur les référentiels et standards de biométrie fœtale. Juin 2017.

This article reports the conclusions and recommendations resulting from the seminar organized in Paris on June 15, 2017 by the scientific committee of the French College of Fetal Ultrasound (CFEF). The purpose of this meeting was to audit the practices in screening for SGA and IUGR fetuses in France and to discuss ways to improve ultrasound screening. A review of charts, references, standards and common practices was performed. The potential new biometric tools applicable in France were reviewed and analyzed. Eventually, options and recommendations for improvement are proposed.

Final height and intrauterine growth retardation.

Approximately 10% of small for gestational age (SGA) children maintain a small body size throughout childhood and often into adult life with a decreased pubertal spurt. Growth hormone (GH) therapy increases short-term growth in a dose-dependent manner and adult height had now been well documented. Shorter children might benefit from a higher dose at start (50µg/kg/day). The response to GH treatment was similar for both preterm and term short SGA groups and the effect of GH treatment on adult height showed a wide variation in growth response. As a whole, mean adult height is higher than -2 SDS in 60% of patients and 70% reached an adult height in their target height with better results with higher doses and combined GnRH analog therapy in those who were short at onset of puberty.

[Detection of small for gestational age fetuses during third trimester ultrasound. A monocentric observational study]. / Détection des fœtus petits pour l'âge gestationnel lors de l'échographie du troisième trimestre. Étude observationnelle monocentrique.

OBJECTIVES: Fetus small for gestational age (SGA) screening rate is evaluated around 21,7 % in France. Recommendations were developed to improve the efficiency of ultrasound conducted in the third trimester (T3), because neonatal consequences can be significant. This study aims to evaluate screening of SGA during T3 ultrasound and to describe causes for failure and differences with the recommendations of CNGOF. METHODS: All children born between 2011 and 2012 with a birth weight below the 3rd percentile were included in this observational, retrospective, monocentric study. We noted that the diagnosis of SGA was placed on file. Then, as recommended by the CNGOF, we calculated estimated fetal weight (EFW) with Hadlock 3 and Hadlock 4, and the corresponding percentiles, using the biometrics from the ultrasound report. We thus could evaluate a new screening rate with SGA fetus identified through this technique. RESULTS: A total of 142 patients were included. By calculating correctly all EFW and checking abdominal circumference percentiles, the screening rate of SGA fetuses with T3 ultrasound increased from 40 % to 50 % and the overall screening rate (clinical and ultrasound) from 54 % to 66 %. CONCLUSION: By following the recommendations we found a real improvement in fetal SGA screening rates to T3 ultrasound with a potential benefit for their care.

Monochorionic diamniotic twin pregnancy with selective IUGR type 2: fetoscopic and sonographic findings of ominous prognosis / Gestación gemelar monocorial complicada con RCIU selectiva tipo 2: hallazgos ecográficos y fetoscópicos de mal pronóstico

A woman with a monochorionic diamniotic twin pregnancy was referred to our Centre due to a discrepancy in size between the foetuses. She was 17 weeks' pregnant when the diagnosis of selective IUGR type 2 was made and the laser ablation of the placental anastomoses was performed. During the fetoscopy, we identified an arterio-venous anastomosis with bidirectional flow, which is atypical in this type of anastomoses (unidirectionals) and could represent a sign of ominous prognosis for the restricted twin.

Presentamos el caso de una gestante de 17 semanas con una gestación gemelar monocoriónica biamniótica complicada con RCIU selectivo tipo 2 que requirió, de acuerdo a criterios ecográficos, ablación quirúrgica láser de las anastomosis placentarias. Se identificó durante la fetoscopia una anastomosis arterio-venosa que mostraba flujo bidireccional lo cual es sumamente inusual en este tipo de anastomosis, no reportado antes en la literatura, constituyendo así un signo de mal pronóstico para el gemelo pequeño.

[The role of oxidative stress in placental-related diseases of pregnancy]. / Le rôle du stress oxydant dans les pathologies placentaires de la grossesse.

In normal pregnancies, the earliest stages of development take place in a low oxygen (O2) environment. This physiological hypoxia of the early gestational sac protects the developing fetus against the deleterious and teratogenic effects of O2free radicals. Oxidative stress is manifested at the maternal-fetal interface from early pregnancy onwards. In early pregnancy, a well-controlled oxidative stress plays a role in modulating placental development, functions and remodelling. Focal trophoblastic oxidative damage and progressive villous degeneration trigger the formation of the fetal membranes, which is an essential developmental step enabling vaginal delivery. Our data have demonstrated that the first trimester placenta in humans is histiotrophic and not haemochorial. The development and maintenance of a physiological O2 gradient between the uterine and fetal circulations is also essential for placental functions, such as transport and hormonal synthesis. Pathological oxidative stress arises when the production of reactive O2 species overwhelms the intrinsic anti-oxidant defences causing indiscriminate damage to biological molecules, leading to loss of function and cell death. We here review the role of oxidative stress in the pathophysiology of miscarriage, pre-eclampsia and fetal growth restriction.

Prokineticin1 and pregnancy.

Prokineticin 1 (PROK1), also called EG-VEGF, is a peptide of 86 amino acids with multiple biological functions. PROK1 acts via two G-protein coupled receptors: PROKR1 PROKR2. PROK1 is highly expressed in the placenta. This article reports the expression and the role of PROK1 during normal and pathological pregnancies: (i) during early pregnancy, PROK1 exhibits a peak of placental expression shortly before the establishment of the feto-maternal circulation; (ii) its receptors, PROKR1 PROKR2 are highly expressed in human placenta; (iii) its expression is increased by hypoxia; (iv) PROK1 inhibits extravillous trophoblasts migration and invasion and increases their proliferation and survival; (v) PROK1 is also a pro-angiogenic placental factor that increases microvascular placental endothelial cells proliferation, migration, invasion, and permeability. Circulating PROK1 levels are five times higher in pregnant women during the first trimester compared to the second and third trimesters. Also, its serum levels are higher in patients with preeclampsia (PE) and in patients with isolated intra-uterine growth restriction (IUGR). In mice, maintaining high level of PROK1 beyond its normal period of production (>10.5dpc) reproduces symptoms of PE. To date, our results demonstrated that PROK1 is a central factor of human placentation with direct roles both in the control of trophoblast invasion and villous growth. Thus, a failure in the expression of PROK1 and/or its receptor during pregnancy may contribute to the development of PE and/or IUGR. Besides theses original findings, we also report a direct role of this factor in parturition.

[Intra-uterine growth restriction impact on maternal serum concentration of PlGF (placental growth factor): A case control study]. / Impact du retard de croissance intra-utérin sur la concentration sérique maternelle du PlGF (Placental Growth Factor) : une étude cas-témoin.

OBJECTIVES: Placental growth factor (PlGF) is a pro-angiogenic factor mainly assessed in preeclampsia in which its blood concentration is decreased. The aim of this study was to dose the blood concentration of PlGF in women with fetal intra-uterine growth restriction (IUGR) without associated preeclampsia at the time of diagnosis. METHODS: Case/control study: IUGR was defined by a fetal biometry with abnormal uterine and/or umbilical doppler (n=23). This group was compared to a control group of fetuses (n=25) matched for gestational age at blood sampling for the dosage of maternal seric PlGF. Women with preeclampsia were not included. RESULTS: The plasma PlGF concentration was 11pg/mL (IQR [11-42,8]) in the IUGR group vs 287pg/mL [135-439] in the control group (P<0.001) and this difference was available after adjustment for gestational age at the time of blood sampling (P<0.001). PlGF sensitivity and specificity for discrimination were respectively 87% (CI 95% [66-97]) and 88% (CI 95% [69-97]). CONCLUSION: Maternal serum PlGF concentrations were very low in IUGR group compared with those of the control group.

[Chart for estimation of fetal weight 2014 by the French College of Fetal Sonography (CFEF)]. / Courbe d'estimation de poids fœtal 2014 par le Collège français d'échographie fœtale (CFEF).

OBJECTIVE: To establish a reference chart for estimated fetal weight (EFW) using the Hadlock formula based on recent biometric data (2012-2013). MATERIAL AND METHODS: A prospective multicentric longitudinal study was carried out. Biometric parameters as the head circumference (HC), abdominal circumference (AC) and the femur length were measured in multiple areas of France from January 2012 until December 2013. EFW was calculated using the predictive formula of Hadlock using three parameters. The accurate gestational age was the main inclusion criteria calculated in weeks of gestation (WG). A polynomial regression approach was used to calculate the mean and standard deviation for every WG adjusted to raw data. Centiles of EFW were calculated from the z score that corresponds to the -1.88, -1.28, 0, +1.28, +1.88 respectively for the 3rd, 10th, 50th, 90th, et 97th percentile in order to establish a new chart of EFW. RESULTS: Measurements were obtained for 33,143 fetus between 17 et 38 WG. Reference charts with the 3rd, 10th, 50th, 90th et 97th percentiles were presented. CONCLUSION: The reference Chart 2014 is an in utero chart for EFW based on ultrasound measurements data reliable and homogenous from a sample of 33,143 fetus of a general population. It offers a tool to use in routine ultrasound examination for the survey of the fetal growth and to diagnose fetus that are small for gestational age or presenting a restriction in growth.

[Long-term outcome in context of intra uterine growth restriction and/or small for gestational age newborns]. / Conséquences à long terme des enfants nés dans un contexte de retard de croissance intra-utérin et/ou petits pour l'âge gestationnel.

OBJECTIVE: To evaluate long-term outcome after history of intra-uterine growth restriction (IUGR) and/or birth small for gestational age (SGA). METHODS: This systematic evidence review is based on Pubmed search, Cochrane library and experts recommendations. RESULTS: Neurodevelopmental evaluation at 2 years is lower in those infants, born premature or not. SGA is associated with a high risk of minor cognitive deficiencies, hyperactivity or attention deficit disorders at 5 years or scholar difficulties at 8 years. Those infants are at high risk of metabolic syndrome in adulthood. Most of them will catch up at 6 months for weight and 12 months for height. Even if IUGR is associated with high risk of bronchodysplasia, up to this day, the review of literature did not permit to evaluate respiratory outcome. Adults born SGA have good quality of live and normal professional insertion. One cohort study and more and more animal studies suggest potential trans generational effects. CONCLUSION: Infants born SGA and/or with history of IUGR are at high risk of minor cognitive deficiencies and scholar difficulties. They are also at high risk of metabolic syndrome in adulthood. However, prematurity seems to have a higher effect than IUGR and/or SGA on long-term outcomes.

[Prenatal management of isolated IUGR]. / Surveillance anténatale, prise en charge et indications de naissance en cas de RCIU vasculaire isolé.

OBJECTIVE: To evaluate the performance of different antenatal tools for the monitoring of fetuses with isolated intrauterine growth restriction (IUGR). To define the prenatal management of IUGR and indications for delivery before and after 32 weeks of gestation. METHOD: PubMed, Embase and the Cochrane databases were searched using the keywords "IUGR", "fetal growth restriction", "cardiotocography", "amniotic fluid", "ultrasound assessment", "biophysical profile", "Doppler ultrasonography", "randomized trial", "meta-analysis". These terms were also combined together. RESULTS: Fetal monitoring of isolated IUGR should be based on the combined use of fetal heart rate (FHR) and ultrasound Doppler. The use of computerized FHR, with short-term variability (STV) measurement allows longitudinal monitoring and provides objective values upon which to decide very premature delivery (LE3). The use of umbilical Doppler is associated with a decrease in perinatal morbidity, especially in IUGR (LE1). It should be the first-line mean for the monitoring of SGA and IUGR fetuses (LE1). The additional use of cerebral Doppler is associated with a better predictive value for a poor perinatal outcome than the umbilical Doppler alone (LE3). Therefore, cerebral Doppler should be used in fetuses with IUGR, whether the umbilical Doppler is normal or not. As morbidity and mortality is increased in IUGR with pathological ductus venosus, the use of this Doppler should be considered in the monitoring of IUGR at before 32 weeks (professional consensus). Routine hospitalization is not mandatory for the monitoring of fetuses with IUGR/SGA. However, tertiary referral is advisable in cases of severe IUGR at between 26 to 32 weeks (professional consensus). The decision for delivery cannot be standardized and should be based on the combined analysis of gestational age, fetal heart rate analysis and Doppler study (professional consensus). CONCLUSION: Monitoring of fetuses with IUGR and decision for delivery should be based on the combined analysis of gestational age, fetal heart rate analysis and Doppler study before 32 weeks, this should ideally be performed by the association of computerized FHR and arterial and venous Doppler.

[Managing and identifying the causes of IUGR]. / Bilan étiologique du retard de croissance intra-utérin (RCIU).

INTRODUCTION: The management and identification of the causes for a small for gestational age (SGA) and/or an intrauterine growth restriction (IUGR) fetus is a common but complex problem in Obstetrics. MATERIALS AND METHODS: The Medline, Embase and the Cochrane Library databases were examined over the last 15 years, with no language restrictions, using a combination of the words PAG (SGA), IUGR (IUGR), fetal weight (Fetal weight), sonography (ultrasound), management, cause (etiology), examinations (examinations). Some references not selected by this strategy, but associated with these publications or suggested by members of the working group were also added. The relevant articles were used to establish the text of recommendation following discussion between experts of the working group. RESULTS: Once the diagnosis of SGA is raised (whether on clinical, echocardiographic or Doppler), a management strategy to look for potential causes must be proposed and discussed with parents (Expert reviews). The extent of additional explorations varies depending on the exact presentation of the case (term at diagnosis, severity of anomalies). Additional explorations only make sense if they are likely to change the management of the current pregnancy and particularly to reduce perinatal morbidity and mortality. Explorations have two main objectives: (i) assess fetal vitality and possibilities for continuing the pregnancy in terms of safety for the mother and the foetus; (ii) establish the origin of SGA. The latter is detailed in this chapter recommendation. The earlier and the more severe the biometric anomalies, the more comprehensive the investigations. Maternal symptoms or fetal Doppler anomalies also require urgent management. CONCLUSION: Explorations to establish the origin of SGA and/or IUGR must follow a rigorous and systematic approach. In all cases, the practitioner will provide clear information to parents and collect information including detailed clinical and ultrasound examinations. Additional tests and in particular fetal invasive testing must be performed in some cases after parental consent and according to clinical and sonographic guidance elements.

[Delivery of the IUGR fetus]. / Modalités de naissance du fœtus porteur d'un RCIU.

OBJECTIVE: The purpose of this paper is to review available data regarding the management of delivery in intra uterine growth retarded fetuses and try to get recommendations for clinical obstetrical practice. MATERIALS AND METHODS: Bibliographic research performed by consulting PubMed database and recommendations from scientific societies with the following words: small for gestational age, intra-uterine growth restriction, fetal growth restriction, very low birth weight infants, as well as mode of delivery, induction of labor, cesarean section and operative delivery. RESULTS: The diagnosis of severe IUGR justifies the orientation of the patient to a referral centre with all necessary resources for very low birth weight or premature infants Administration of corticosteroids for fetal maturation (before 34 WG) and a possible neuroprotective treatment by with magnesium sulphate (before 32-33 WG) should be discussed. Although elective caesarean section is common, there is no current evidence supporting the use of systematic cesarean section, especially when the woman is in labor. Induction of labor, even with unfavorable cervix is possible under continuous FHR monitoring, in favorable obstetric situations and in the absence of severe fetal hemodynamic disturbances. Instrumental delivery and routine episiotomy are not recommended. For caesarean section under spinal anesthesia, an adequate anesthetic management must ensure the maintenance of basal blood pressure. CONCLUSION: Compared with appropriate for gestational age fetus, IUGR fetus is at increased risk of metabolic acidosis or perinatal asphyxia during delivery.

Identification of messenger RNA of fetoplacental source in maternal plasma of women with normal pregnancies and pregnancies with intrauterine growth restriction / Identificacion de RNA mensajero de origen fetoplacentario en plasma materno de mujeres con embarazos normales y gestantes con restriccion de crecimiento intrauterino

Objective: to quantify placenta-specific RNA in plasma of women carrying foetuses with intrauterine growth restriction and pregnant women with normal pregnancies. Materials and methods: 8 pregnant women with foetuses with intrauterine growth restriction were studied as well as 18 women with uncomplicated pregnancies in the third pregnancy trimester. Total free RNA was quantified in maternal plasma by spectrophotometry and the gene expression of hPL (Human Placental Lactogen) at the messenger RNA level through technical Real Time-Chain Reaction Polymerase. Results: plasma RNA of fetoplacental origin was successfully detected in 100% of pregnant women. There were no statistically significant differences between the values of total RNA extracted from plasma (p = 0.5975) nor in the messenger RNA expression of hPL gene (p = 0.5785) between cases and controls. Conclusion: messenger RNA of fetoplacental origin can be detected in maternal plasma during pregnancy.(AU)Objective: to quantify placenta-specific RNA in plasma of women carrying foetuses with intrauterine growth restriction and pregnant women with normal pregnancies. Materials and methods: 8 pregnant women with foetuses with intrauterine growth restriction were studied as well as 18 women with uncomplicated pregnancies in the third pregnancy trimester. Total free RNA was quantified in maternal plasma by spectrophotometry and the gene expression of hPL (Human Placental Lactogen) at the messenger RNA level through technical Real Time-Chain Reaction Polymerase.Results: plasma RNA of fetoplacental origin was successfully detected in 100% of pregnant women. There were no statistically significant differences between the values of total RNA extracted from plasma (p = 0.5975) nor in the messenger RNA expression of hPL gene (p = 0.5785) between cases and controls.Conclusion: messenger RNA of fetoplacental origin can be detected in maternal plasma during pregnancy

Objetivo: cuantificar RNA específico de placenta en el plasma de mujeres con embarazos con fetos con Restricción de Crecimiento Intrauterino y gestantes con embarazos normales. Materiales y métodos: se estudiaron 8 mujeres con embarazos con fetos con Restricción de Crecimiento Intrauterino y 18 mujeres con embarazos sin complicaciones, en el tercer trimestre de embarazo. Se cuantificó el RNA total libre en plasma materno por espectrofotometría y la expresión del gen hPL (Lactógeno Placentario Humano) a nivel de RNA mensajero por medio de la técnica Reacción en Cadena de la Polimerasa en Tiempo Real. Resultados: se logró detectar RNA en plasma de origen fetoplacentario en el 100% de las gestantes. No se encontraron diferencias estadísticamente significativas entre los valores de RNA total extraído de plasma (p=0,5975) ni en la expresión del RNA mensajero del gen hPL (p=0,5785) entre casos y controles. Conclusión: es posible detectar RNA mensajero de origen fetoplacentario en plasma materno durante el embarazo.

Identification of messenger RNA of fetoplacental source in maternal plasma of women with normal pregnancies and pregnancies with intrauterine growth restriction.

OBJECTIVE: to quantify placenta-specific RNA in plasma of women carrying foetuses with intrauterine growth restriction and pregnant women with normal pregnancies. METHODS: 8 pregnant women with foetuses with intrauterine growth restriction were studied as well as 18 women with uncomplicated pregnancies in the third pregnancy trimester. Total free RNA was quantified in maternal plasma by spectrophotometry and the gene expression of hPL (Human Placental Lactogen) at the messenger RNA level through technical Real Time-Chain Reaction Polymerase. RESULTS: plasma RNA of fetoplacental origin was successfully detected in 100% of pregnant women. There were no statistically significant differences between the values of total RNA extracted from plasma (p= 0.5975) nor in the messenger RNA expression of hPL gene (p= 0.5785) between cases and controls. CONCLUSION: messenger RNA of fetoplacental origin can be detected in maternal plasma during pregnancy.

OBJETIVO: cuantificar RNA específico de placenta en el plasma de mujeres con embarazos con fetos con Restricción de Crecimiento Intrauterino y gestantes con embarazos normales. MÉTODOS: se estudiaron 8 mujeres con embarazos con fetos con Restricción de Crecimiento Intrauterino y 18 mujeres con embarazos sin complicaciones, en el tercer trimestre de embarazo. Se cuantificó el RNA total libre en plasma materno por espectrofotometría y la expresión del gen hPL (Lactógeno Placentario Humano) a nivel de RNA mensajero por medio de la técnica Reacción en Cadena de la Polimerasa en Tiempo Real. RESULTADOS: se logró detectar RNA en plasma de origen fetoplacentario en el 100% de las gestantes. No se encontraron diferencias estadísticamente significativas entre los valores de RNA total extraído de plasma (p= 0.5975) ni en la expresión del RNA mensajero del gen hPL (p= 0.5785) entre casos y controles. CONCLUSIÓN: es posible detectar RNA mensajero de origen fetoplacentario en plasma materno durante el embarazo.