Hypertensive disorders of pregnancy and neonatal outcomes in twin vs. singleton pregnancies after assisted reproductive technology

Synergistic effect between pre-pregnancy smoking and assisted reproductive technology on gestational diabetes mellitus in twin pregnancies

AIM

Women with twin pregnancies have an increased risk of gestational diabetes mellitus (GDM). Assisted reproductive technology (ART) and pre-pregnancy smoking were both associated with GDM. However, the relationships between pre-pregnancy smoking and ART and GDM in twin pregnancies were unclear. Herein, this study aims to explore the roles of pre-pregnancy smoking and ART in GDM among women with twin pregnancies.

METHODS

Data of women with twin pregnancies were extracted from the National Vital Statistics System (NVSS) database in 2016-2020 in this retrospective cohort study. Univariate and multivariate logistic regression analyses were used to explore the associations between pre-pregnancy smoking and ART and GDM in women with twin pregnancies. The evaluation index was odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analysis of age and BMI was also performed.

RESULTS

A total of 19,860 (9.15%) women had GDM in our study. After adjusting for covariates, we found that receiving ART was associated with high odds of GDM [OR = 1.41, 95% CI (1.34-1.48)], while pre-pregnancy smoking combined with ART was associated with higher odds of GDM [OR = 1.66, 95% CI (1.14-2.42)]. In addition, these relationships were also found in women who aged ≥ 35 years old [OR = 1.98, 95% CI (1.14-3.44)] and with BMI ≥ 25 kg/m2 [OR = 1.69, 95% CI (1.11-2.55)].

CONCLUSION

Pre-pregnancy smoking may further increase the risk of GDM from ART in women with twin pregnancies. In clinical, women who are ready to receive ART treatment are recommend to quit smoking, which may reduce the risk of GDM and prevent adverse pregnancy outcomes.

Potential impact on using aspirin as the primary prevention of adverse pregnancy outcomes in twins conceived using ART

With the development of assisted reproductive technology, the number of twin pregnancies is increasing year by year. Given the increased risk of pregnancy complications associated with twin pregnancies, and the fact that these babies are rare and difficult to obtain through assisted reproductive technology, clinicians urgently require finding effective and safe drugs to improve pregnancy outcomes. Low-dose aspirin can not only promote placental blood supply, but also effectively anti-inflammatory. Whether Low-dose aspirin can effectively reduce the risk of pregnancy complications in this special group needs to be clarified. We therefore retrospectively analyzed 665 twin pregnancies from assisted reproduction technology, grouped according to aspirin use, and followed pregnancy outcomes to assess bleeding risk. Low-dose aspirin was found to be effective in preventing preeclampsia without a significant risk of bleeding. However, aspirin does not prevent specific complication in twin pregnancies and seems to have a better preventive effect only when the mother is under 30, which should alarm clinicians should not blindly using aspirin in this particular group.

The interaction effect of pre-pregnancy body mass index and maternal age on the risk of pregnancy complications in twin pregnancies after assisted reproductive technology

OBJECTIVE

The widespread use of assisted reproductive technology (ART) has led to an increased twin pregnancy rate and increased risk of pregnancy complications. Pre-pregnancy body mass index (BMI) and maternal age are both risk factors for pregnancy complications. This study aimed to explore whether there is an interaction effect between pre-pregnancy BMI and maternal age on pregnancy complications in women with twin pregnancies after ART.

METHODS

Data of 445,750 women with twin pregnancies after ART were extracted from the National Vital Statistics System (NVSS) database in 2016-2021 in this retrospective cohort study. Univariate and multivariate logistic regression analyses were used to explore (1) the associations between pre-pregnancy BMI, maternal age, and total pregnancy complications; (2) interaction effect between pre-pregnancy BMI and maternal age on total pregnancy complications; and (3) this interaction effect in parity, race, gestational weight gain (GWG), and preterm birth subgroups. The evaluation indexes were odds ratios (ORs), relative excess risk of interaction (RERI), attributable proportions of interaction (AP), and synergy index (S) with 95% confidence intervals (CIs).

RESULTS

A total of 6,827 women had pregnancy complications. After adjusting for the covariates, compared with women had non-AMA and pre-pregnancy BMI <25 kg/m2, higher maternal age combined with higher pre-pregnancy BMI was associated with higher odds of total pregnancy complications [OR = 2.16, 95%CI: (1.98-2.36)]. The RERI (95% CI) was 0.22 (0.04-0.41), AP (95% CI) was 0.10 (0.02-0.19), and S (95% CI) was 1.24 (1.03-1.49). Subgroup analysis results indicated that the potential additive effect between pre-pregnancy BMI and maternal age on total pregnancy complications was also found in women with different race, multipara/unipara, GWG levels, or preterm births/non-preterm births (all p < 0.05).

CONCLUSION

Pre-pregnancy BMI and maternal age may have an additive effect on the odds of pregnancy-related complications in women with twin pregnancy after ART.

Association between pre-pregnancy body mass index and the risk of preterm birth: a mediating effect of hypertensive disorders of pregnancy

OBJECTIVE

We aim to explore the mediating effect of hypertensive disorders of pregnancy (HDP) on the relationship between pre-pregnancy body mass index (BMI) and the risk of preterm birth (PTB) in women with singleton live births.

METHODS

Demographic and clinical data of 3,249,159 women with singleton live births were extracted from the National Vital Statistics System (NVSS) database in this retrospective cohort study. The associations between pre-pregnancy BMI and HDP, HDP, and PTB, and pre-pregnancy BMI and PTB were evaluated using univariate and multivariate logistic regression analyses, with odds ratios (ORs) and 95% confidence intervals (CIs). Structural equation modeling (SEM) was used to explore the mediating effect of HDP on the relationship between pre-pregnancy BMI and PTB.

RESULTS

In total, 324,627 women (9.99%) had PTB. After adjustment for covariables, there were significant associations between pre-pregnancy BMI and HDP [OR = 2.07, 95% CI: 2.05-2.09)], HDP and PTB [OR = 2.54, 95% CI: (2.52-2.57)], and pre-pregnancy BMI and PTB [OR = 1.03, 95% CI: 1.02-1.03)]. The effect of pre-pregnancy BMI on PTB was significantly mediated by HDP with a mediation proportion of 63.62%, especially in women of different ages and having gestational diabetes mellitus (GDM) or not.

CONCLUSION

HDP may play a mediating role in the effect of pre-pregnancy BMI on PTB risk. Women preparing for pregnancy should pay close attention to BMI, and pregnant women should monitor and develop interventions for HDP to reduce the risk of PTB.

Impact of hypertensive disorders of pregnancy on maternal and neonatal outcomes of twin gestation: a systematic review and meta-analysis

Background

The impact of hypertensive disorders of pregnancy (HDP) on outcomes of twin gestations is not clear. We aimed to collate data via this meta-analysis to examine how HDP alters maternal and neonatal outcomes of twin gestations.

Methods

Studies comparing pregnancy outcomes of twin gestations based on HDP and published on the databases of PubMed, CENTRAL, Scopus, Web of Science, and Embase between 1 January 2000 to 20 March 2023 were eligible for inclusion.

Results

Twelve studies were included. A cumulative of 355,129 twin gestations were analyzed in the current meta-analysis. The pooled analysis found that the presence of HDP increases the risk of preterm birth (OR: 1.86 95% CI: 1.36, 2.55 I2 = 99%) and cesarean section in twin gestations (OR: 1.36 95% CI: 1.20, 1.54 I2 = 89%). Meta-analysis showed a significantly increased risk of low birth weight (OR: 1.30 95% CI: 1.10, 1.55 I2 = 97%), small for gestational age (OR: 1.30 95% CI: 1.09, 1.55 I2 = 96%) and neonatal intensive care unit admissions (OR: 1.77 95% CI: 1.43, 2.20 I2 = 76%) with HDP in twin gestations. There was no difference in the incidence of 5-min Apgar scores <7 (OR: 1.07 95% CI: 0.87, 1.38 I2 = 79%) but a lower risk of neonatal death (OR: 0.39 95% CI: 0.25, 0.61 I2 = 62%) with HDP.

Conclusion

HDP increases the risk of preterm birth, cesarean sections, low birth weight, SGA, and NICU admission in twin gestations. Contrastingly, the risk of neonatal death is reduced with HDP. Further studies are needed to corroborate the current results.

Systematic Review Registration

PROSPERO (CRD42023407725).