The mediation effect of multiple gestations on the association between in vitro fertilisation and severe maternal morbidities: a retrospective cohort study

Abstract

ObjectiveTo investigate whether the association between in vitro fertilisation (IVF) and severe maternal morbidity (SMM) was mediated by multiple gestations.DesignA retrospective cohort study.SettingThe study was conducted at six hospitals in China.ParticipantsPregnant women at 20 gestational weeks or longer.Outcome measureThe outcome was SMM, which was a composite of potential life-threatening conditions, the use of critical medical interventions, or the status of maternal near-miss that occurred during pregnancy, childbirth or within 42 days of pregnancy termination, as defined by WHO.ResultsIn total, 22 368 eligible pregnant women were included, among whom 497 (2.2%) received IVF, and 776 developed SMM (incidence 34.7/1000 live births, 95% CI 32.3/1000 to 37.1/1000). Four multivariable logistic regression models were constructed. Model 1, without including the variable of multiple gestations, showed that IVF was associated with higher risk of SMM (adjusted OR (aOR) 1.54, 95% CI 1.03 to 2.29). Model 2, assessing the association between IVF and multiple gestations, showed that IVF was strongly associated with multiple gestations (aOR 14.75, 95% CI 11.38 to 19.10). Model 3, by adding the variable of multiple gestations to model 1, showed that IVF was not statistically associated with SMM (aOR 0.89, 95% CI 0.58 to 1.36), but multiple gestations were associated with higher risk of SMM (aOR 5.92, 95% CI 4.88 to 7.83). Model 4, investigating the association between IVF and SMM among singleton pregnancies, showed no statistically significant association (aOR 0.70, 95% CI 0.37 to 1.32). An additional analysis by adding the interaction term of IVF by multiple gestations to model 3 showed no statistical significance of the interaction term (aOR 1.15, 95% CI 0.36 to 3.68), confirming the absence of exposure-mediator interaction.ConclusionsUsing the established rule for judging mediation effect, the results suggested that multiple gestations might mediate the association between the use of IVF and higher risk of SMM. Further prospective studies are warranted to test our finding.

A retrospective study of the comparison of maternal outcomes in in-vitro-fertilization pregnancy versus spontaneous conception

“…In a retrospective multicentre cohort study by Tan et al 18.7% of women conceived via IVF had multiple pregnancies versus only 1.53% of spontaneous conception (p<0.001). [7][8][9] Increased risk of gestational diabetes mellitus has been observed in many studies done so far similar to that observed in our study. The most probable reason sighted is the high prevalence of polycystic ovarian syndrome in females with infertility.…”

Dose–response association between maternal pre-pregnancy bodyweight and gestational diabetes mellitus following ART treatment: a population-based cohort study

“…In conception achieved by ART, multiple gestations usually increase the risk of adverse pregnancy outcomes [ 31 , 32 ]. A previous study indicated that GDM following ART was more common in multiple gestations compared to singleton with OR of 1.30 (95% CI 1.10–1.54) [ 33 ].…”

The use of IVF/ICSI and risk of postpartum hemorrhage: A retrospective cohort study of 153,765 women in China

“…In all analyses, we adjusted for maternal demographic factors, pregnancy-related complications and reproductive history that have been suggested to be associated with postpartum bleeding (24)(25)(26)(27). Those covariate variables included maternal age at delivery, parity, gravidity, hypertensive disorders in pregnancy (HDP), GDM, mode of delivery, prolonged second stage of labor, intra-amniotic infection, gestational age at delivery, newborn birthweight, and placental abnormality (placental abruption, placenta previa, low-lying placenta, placenta accrete and increta).…”