Early fetal growth in progesterone-treated IVF pregnancies

Prediction of Adverse Pregnancy Outcomes Using Crown-Rump Length at 11 to 13 + 6 Weeks of Gestation

OBJECTIVES

To assess the risk of a fetus with a smaller or larger than expected crown-rump length (CRL) for adverse pregnancy outcomes.

METHODS

The data of 960 healthy singleton pregnancies conceived via in vitro fertilization were retrospectively collected. Fetal CRL was measured between 11 and 13 + 6 weeks of gestation, and small and large fetal CRLs were defined as fetuses below the 10th and above the 90th centiles, respectively. Multiple logistic regression analysis was performed to assess the risk for adverse pregnancy outcomes.

RESULTS

The mean birth weights of fetuses with small, normal, and large CRLs were 3002 g, 3205 g, and 3378 g, respectively. A small fetal CRL was associated with an increased risk of smaller-than-gestational-age neonates (adjusted odds ratio [aOR], 2.79; 95% confidence interval [CI], 1.53-5.08; P < .001) and preterm delivery before 34 gestational weeks (aOR, 6.48; 95% CI, 1.36-30.79; P = .019). A large fetal CRL was associated with an increased risk of large-for-gestational-age (LGA) neonates, and the risk persisted even after adjustment for well-known risk factors of macrosomia, such as pre-pregnancy body mass index, gestational diabetes, and excessive gestational weight gain (aOR, 3.67; 95% CI, 2.04-6.59; P < .001). However, a large fetal CRL was associated with a decreased risk of gestational diabetes (aOR, 0.10; 95% CI, 0.01-0.76; P = .026).

CONCLUSIONS

Fetal CRL measured at 11 to 13 + 6 weeks gestation is worth using as a predictor of LGA as well as small for gestational age or preterm delivery.

Maternal cadmium exposure during late pregnancy causes fetal growth restriction via inhibiting placental progesterone synthesis

Cadmium (Cd) is a major environmental pollutant. Maternal Cd exposure throughout pregnancy caused fetal growth restriction (FGR). However, the pivotal time window of Cd-evoked FGR and its mechanism are unknown. Here, we will establish a murine model to explore the effects of maternal Cd exposure at different stages of gestation on fetal growth and placental progesterone biosynthesis. Pregnant mice were randomly divided into four groups. For Cd groups, mice were given with CdCl₂ (150 mg/L) through drinking water at early (GD0-GD6), middle (GD7-GD12) and late (GD13-GD17) gestation, respectively. The controls received reverses osmosis (RO) water. Results showed that maternal cadmium exposure only in late gestation lowered fetal weight and length. Correspondingly, placental Cd level in late gestational Cd exposure is the highest among three different gestational stages. Although gestational Cd exposure had few adverse effects in the weight and diameter of mouse placenta, placental vascular development, as determined by H&E staining and cluster of differentiation-34 (CD-34) immunostaining, was impaired in mice exposed to Cd during late pregnancy. Additionally, late gestational exposure to cadmium markedly reduced progesterone level in maternal serum and placenta. In line, the expression of key progesterone synthetases, including steroidogenic acute regulatory protein (StAR) and 3β-hydroxyl steroid dehydrogenase (3β-HSD), was obviously downregulated in placenta from mice was exposed Cd during late pregnancy. These data suggest that maternal Cd exposure during late pregnancy, but not early and middle pregnancy, induces fetal growth restriction partially via inhibiting placental progesterone synthesis.

Maternal progesterone levels are modulated by maternal BMI and predict birth weight sex-specifically in human pregnancies

OBJECTIVE

Successful pregnancy outcome is the result of a tailored adaptation of the maternal endocrine and immune system throughout gestation. We aimed to investigate if maternal endocrine, anthropometric and life style factors assessed longitudinally throughout pregnancy allow prediction of birth weight.

STUDY DESIGN

Data on maternal factors and obstetrical characteristics from 220 pregnancies from a German prospective pregnancy cohort were analyzed using univariate and multivariate regression models. The association between maternal progesterone levels at the end of the 1st (gw 12-14), the 2nd (gw 22-24) and the 3rd trimester (gw 34-36) and birth weight of children born at term was examined. Interaction terms were included to identify possible sex-specific associations. Furthermore, associations between maternal and obstetric characteristics and progesterone levels were tested.

RESULTS

After controlling for possible confounders, progesterone in the 2nd trimester emerged as an independent predictor for birth weight in pregnancies with female (p=0.01), but not male fetuses (p=0.6). In female fetuses each increase of progesterone by 1ng/ml in the 2nd trimester was associated with an increase of birth weight by 6.8g (95%-CI=1.44-12.24). Maternal 1st trimester BMI showed a significant inverse correlation to progesterone levels throughout gestation (p<0.0001 in the 1st and 2nd, p=0.01 in the 3rd trimester). This inverse association between maternal BMI and progesterone levels was confined to overweight women.

CONCLUSION

Our data support that maternal progesterone levels have the potential to serve as early biomarker for reduced birth weight and underpins the importance of normal weight when entering the reproductive phase.