Risk factors associated with pre-eclampsia in pregnancies conceived by ART

Association between serum hormone levels in early pregnancy and risk of hypertensive diseases of pregnancy in women undergoing assisted reproduction

PURPOSE

We examined the association between progesterone (P4), estradiol (E2), and human chorionic gonadotropin (hCG) levels in early pregnancy and the development of hypertensive diseases of pregnancy among women undergoing assisted reproduction.

METHODS

Retrospective study including patients who underwent frozen embryo transfer (FET), ovarian stimulation (OS), or unassisted conception (UC) and had a live singleton birth. The primary outcome was the development of hypertensive diseases of pregnancy (gestational hypertension, preeclampsia, HELLP, or eclampsia). Secondary outcomes were the development of fetal intrauterine growth restriction (IUGR), gestational diabetes mellitus, birth weight, and pre-term birth. Hormone levels and the development of the outcomes were correlated.

RESULTS

A total of 681 patients were included; 189 had FET, 193 had OS, and 299 had UC. Patients undergoing FET or OS were not more likely to develop hypertensive diseases of pregnancy compared with UC patients. While median levels of E2 and P4 were significantly different between P-FET and NC-FET patients (E2: 252 vs 317 pg/mL, P4: 64 vs 29 ng/mL, respectively; both p < 0.01), rates of hypertensive diseases of pregnancy did not significantly differ between those two groups. In the multivariate analyses, P4, E2, and hCG were not associated with the development of hypertensive diseases of pregnancy, but progesterone levels were significantly higher among those with IUGR. This remained consistent when the analysis was limited to FET patients.

CONCLUSION

P4, E2, and hCG levels did not correlate with the development of hypertensive diseases of pregnancy but elevated progesterone levels did correlate with the development of IUGR.

Comparing the occurrence rate of gestational hypertension during pregnancy with frozen embryo transfer and natural pregnancy

Introduction

Recent researches have indicated that pregnancies with frozen embryo transfer are associated with the increment of risk of maternal and neonatal complications, especially hypertension during pregnancy. The present study aimed to compare the occurrence rate of gestational hypertension in pregnancy with frozen embryo transfer and normal pregnancy.

Materials and Methods

This research, as a retrospective cross-sectional study, was performed on pregnant women with frozen embryo transfer (n = 97) and women with normal pregnancies (n = 164) referring to medical centers under the supervision of Ahvaz University of Medical Sciences in 2021. Women aged 18-35 were included in the study after week 20th of pregnancy. Maternal and neonatal outcomes including hypertensive disorders of pregnancy (including gestational hypertension and preeclampsia), preterm birth (before the week 37th), low birth weight (lower than 2500 g), neonatal asphyxia (Apgar score >7 in minute 5th), intrauterine growth restriction (IUGR) and bleeding in the first trimester of pregnancy were evaluated. The association between frozen embryo transfer and pregnancy outcomes was evaluated using multiple logistic regressions.

Results

The findings of this study indicated that pregnancy hypertension was observed in 23 people (23.7%) from the frozen embryo transfer group vs. 18 people (11.0%) from the normal pregnancy group (P = 0.006). Frozen embryo transfer pregnancy has a higher risk of gestational hypertension (OR = 2.521, 95% CI: 1.281-4.962; P = 0.007), preterm birth (OR = 2.264, 95% CI: 1.335-3.840; P = 0.002), and low birth weight (OR = 2.017, 95% CI: 1.178-3.455; P = 0.011). However, the incidence of birth asphyxia (P = 0.850), intrauterine growth restriction (P = 0.068), first-trimester bleeding (P = 0.809), and placenta accreta (P = 0.143) did not show a significant difference between two types of normal pregnancy and frozen embryo transfer pregnancy.

Conclusion

Frozen embryo transfer pregnancy was associated with a higher risk of maternal and neonatal complications, hypertension, preterm birth, and low birth weight compared to natural and spontaneous pregnancies.

Plastic used in in vitro fertilization procedures induces massive placental gene expression alterations

BACKGROUND

The exposure to plastic derivatives during human life is deleterious. Infants conceived using ART (IVF or ICSI) have twice as many risks of major birth defects compared to naturally conceived infants. Could plastic ware used during ART trigger defects in the fetal development?

METHODS

Three groups of blastocysts were transferred to pseudopregnant mice. One was obtained after IVF and embryo development in plastic ware, the second in glass ware. The third, was obtained in vivo by natural mating. On day 16.5 of pregnancy, females were sacrificed and fetal organs collected for gene expression analysis. Fetal sex was determined by RT-PCR. RNA was extracted from a pool of five placental or brain samples coming from at least two litters from the same group and analyzed by hybridisation onto the mouse Affymetrix 430.2.0 GeneChips, confirmed by RT-qPCR for 22 genes.

FINDINGS

This study highlights a major impact of plastic ware on placental gene expression (1121 significantly deregulated genes), while glassware was much closer to in vivo offspring (only 200 significantly deregulated genes). Gene Ontology indicated that the modified placental genes were mostly involved in stress, inflammation and detoxification. A sex specific analysis revealed in addition a more drastic effect on female than male placentas. In the brains, whatever the comparison, less than 50 genes were found deregulated.

INTERPRETATION

Embryos incubated in plastic ware resulted in pregnancy with massive alterations of placental gene expression profile in concerted biological functions. There were no obvious effects on the brains. Besides other effects, this suggests that plastic ware in ART could be a cause of the increased level of pregnancy disorders observed recurrently in ART pregnancies.

FUNDING

This study was funded by two grants from the Agence de la Biomedecine in 2017 and 2019.

Thin endometrium is associated with the risk of hypertensive disorders of pregnancy in fresh IVF/ICSI embryo transfer cycles: a retrospective cohort study of 9,266 singleton births

BACKGROUND

Thin endometrial thickness (EMT) has been suggested to be associated with reduced incidence of pregnancy rate after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment, but the effect of thin endometrium on obstetric outcome is less investigated. This study aims to determine whether EMT affects the incidence of obstetric complications in fresh IVF/ICSI-embryo transfer (ET) cycles.

METHODS

We conducted a retrospective cohort study collecting a total of 9266 women who had singleton livebirths after fresh IVF/ICSI-ET treatment cycles at the Center for Reproductive Medicine Affiliated to Shandong University between January 2014 and December 2018. The women were divided into three groups according to the EMT: 544 women with an EMT ≤8 mm, 6234 with an EMT > 8-12 mm, and 2488 with an EMT > 12 mm. The primary outcomes were the incidence of obstetric complications including hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), placental abruption, placenta previa, postpartum hemorrhage (PPH) and cesarean section. Multivariable logistic regression analysis was performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for associations between the EMT measured on the day of human chorionic gonadotropin (HCG) trigger and the risk of the outcomes of interest.

RESULTS

The HDP incidence rate of pregnant women was highest in EMT ≤ 8 mm group and significantly higher than those in EMT from > 8-12 mm and EMT > 12 mm group, respectively (6.8% versus 3.6 and 3.5%, respectively; P = 0.001). After adjustment for confounding variables by multivariate logistic regression analysis, a thin EMT was still statistically significant associated with an increased risk of HDP. Compared with women with an EMT > 8-12 mm, women with an EMT ≤8 mm had an increased risk of HDP (aOR = 1.853, 95% CI 1.281-2.679, P = 0.001).

CONCLUSION

A thin endometrium (≤8 mm) was found to be associated with an increased risk of HDP after adjustment for confounding variables, indicating that the thin endometrium itself is a risk factor for HDP. Obstetricians should remain aware of the possibility of HDP when women with a thin EMT achieve pregnancy through fresh IVF/ICSI-ET treatment cycles.

Higher gestational weight gain and lower serum estradiol levels are associated with increased risk of preeclampsia after in vitro fertilization

PURPOSE

To assess the association of preeclampsia with serum estradiol (E2) and progesterone (P4) levels on the day of human chorionic gonadotropin (hCG) administration during controlled ovarian hyperstimulation (COH) for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

METHODS

This was a hospital-based cohort study using clinical data from the Kaohsiung Chang Gung Memorial Hospital Obstetric and Neonatal Database (KCGMHOND) from Jan 1, 2001 to December 1, 2018.

RESULTS

A total of 622 women who had live births after fresh IVF/ICSI-ET during the study period met our inclusion criteria. Twenty-eight women (4.5%) met the diagnostic criteria for preeclampsia. However, women in the preeclampsia group had a significantly higher body weight at delivery (80.5 vs. 70.0 kg, p < 0.001) and gestational weight gain (19.6 vs. 13.0 kg, p = 0.002) and had lower use of ICSI (10.7% vs. 29.9%, p = 0.021). We performed logistic regression analysis of the relationship of patient and treatment characteristics with preeclampsia. The crude ORs indicated that young female age ≤ 34, not using ICSI, E2 on hCG day < 1200 pg/mL and gestational weight gain > 20 kg were associated with preeclampsia. After adjustment for confounding, the only factors that remained significant were E2 on hCG day < 1200 pg/mL (aOR = 4.634, 95% CI = 1.061-20.222), and gestational weight gain > 20 kg (aOR: 13.601, 95% CI: 3.784, 48.880).

CONCLUSIONS

For women receiving IVF/ICSI, lower estradiol hormone levels on the day of hCG administration and higher pregnancy weight gain are related with subsequent preeclampsia.