Reference ranges of anti-Müllerian hormone and interaction with placental biomarkers in early pregnancy: the Generation R Study, a population-based prospective cohort study.

Objective: The primary objective of this study is to establish maternal reference values of anti-Müllerian hormone (AMH) in a fertile multi-ethnic urban pregnant population and to evaluate the effect of gestational age. The secondary objective of this study is to explore the association between AMH and placental biomarkers. Design: This study was embedded in the Generation R Study, an ongoing population-based prospective cohort study from early pregnancy onwards. Setting: City of Rotterdam, the Netherlands, out of hospital setting. Patients: In 5806 women, serum AMH levels were determined in early pregnancy (median 13.5 weeks; 95% range 10.5-17.2). Intervention(s): None. Main outcome measures: Maternal AMH levels in early pregnancy and its association with placental biomarkers, including human chorionic gonadotrophin (hCG), soluble fms-like tyrosine kinase-1 (sFLT), and placental growth factor (PLGF). Results: A nomogram of AMH in early pregnancy was developed. Serum AMH levels showed a decline with advancing gestational age. Higher AMH levels were associated with a higher level of the placental biomarkers hCG and sFLT in early pregnancy. This last association was predominantly mediated by hCG. AMH levels were negatively associated with PLGF levels. Conclusion: In this large study, we show that AMH levels in early pregnancy decrease with advancing gestational age. The association between AMH and the placental biomarkers hCG, sFLT, and PLGF suggests a better placental development with lower vascular resistance in mothers with higher AMH levels. Hence, AMH might be useful in predicting adverse pregnancy outcomes due to impaired placental development.

Fetal sex dependency of maternal vascular adaptation to pregnancy: a prospective population-based cohort study.

OBJECTIVE: To investigate fetal sex dependency of maternal vascular adaptation to pregnancy as assessed by uteroplacental vascular resistance and maternal blood pressure. DESIGN: Prospective population-based cohort study. SETTING: Rotterdam, the Netherlands. POPULATION: In total, 8224 liveborn singleton pregnancies were included. METHODS: Maternal vascular adaptation was assessed in all trimesters of pregnancy. Pregnancies were stratified into being either complicated by the placental syndrome (i.e. pre-eclampsia, fetal growth restriction or preterm birth, n = 1229) or uncomplicated (n = 6995). MAIN OUTCOME MEASURES: First trimester: blood pressures. Second trimester: blood pressures, pulsatility index of the uterine artery (PI-UtA). Third trimester: blood pressures, PI-UtA, presence of notching in the uterine artery. RESULTS: In women carrying a male fetus PI-UtA was higher than in women with a female fetus in the total group (second trimester P < 0.001, third trimester P = 0.005). Effect estimates differed between women with or without the placental syndrome. In the total group, women with a male fetus more often showed notching in the Doppler resistance pattern (odds ratio 1.42, 95% confidence interval 1.17-1.72). Different blood pressure patterns were observed between pregnant women with a male fetus and pregnant women with a female fetus and between complicated pregnancies and uncomplicated pregnancies. CONCLUSION: Fetal sex is significantly associated with maternal vascular adaptation to pregnancy with differential effects in uncomplicated pregnancies and in pregnancies complicated by the placental syndrome. TWEETABLE ABSTRACT: Fetal sex is significantly associated with maternal vascular adaptation to pregnancy.

Fetal sex specific differences in human placentation: a prospective cohort study.

INTRODUCTION: Our objective was to assess fetal sex specific differences in first trimester placental biomarkers of both physiological and pathological pregnancies and their interaction with environmental influences. This study is embedded in the Generation R Study, a prospective cohort study. METHODS: Only live singleton births were included. Linear regression was performed to assess the effect of sex on first trimester placental biomarkers. Interaction analyses were performed to assess interaction of fetal sex with environmental influences. First trimester soluble fms-like tyrosine kinase (s-Flt1), placental growth factor (PLGF), plasminogen activator inhibitor (PAI-2) and homocysteine levels were assessed. RESULTS: Significant fetal sex specific differences in placental biomarkers were observed. S-Flt1, PAI-2 and PLGF log transformated concentrations were 0.08 ng/mL (95% CI 0.05; 0.11), 0.07 ng/mL (95% CI 0.06; 0.09) and 0.04 pg/mL (95% CI 0.01; 0.06) higher in case of female as compared to male placentas. In pregnancies complicated by pre-eclampsia (PE), preterm birth (PTB) or a newborn being small for gestational age (SGA) no fetal sex specific differences were observed. Interaction analyses suggest that concentrations of s-Flt1, PLGF and PAI-2 decrease in male placentas in the case of hyperhomocysteinemia but remain equal in female placentas. DISCUSSION: Fetal sex affects early placentation processes with discrepancies regarding pregnancies complicated by PE, PTB or a newborn being SGA. This suggests that other mechanisms causing these complications may dominate the fetal sex effect. The differences concerning homocysteine suggest that fetal sex dependent placental gene-environment interactions exist. CONCLUSION: Fetal sex specific differences in placental biomarkers exist.