Abstract
Background
Previous studies have confirmed that in-vitro fertilization (IVF) is associated with higher risks of placenta abnormalities and complications. Considering the increased risk of twin and higher-order multiple pregnancies, we tried to investigate the association between IVF and the risk of placenta outcomes in twin pregnancies.
Methods
This retrospective cohort study included 3845 cases of twin pregnancies delivered at Chongqing Health Center for Women and Children (CQHCWC) between 2017 and 2022. Poisson regression modeling with restricted cubic splines of exact maternal age was used to estimate the absolute risk of placenta outcomes in IVF and non-IVF groups. Main outcomes include placenta abnormalities (placenta previa, placental abruption, placenta accrete, and abnormal morphology of placenta) and placenta-related complications (gestational hypertension, preeclampsia, eclampsia, preterm birth, fetal distress, and fetal growth restriction (FGR)). To dissect the influence of chorionicity on the results, we further did the same analysis on the mono- and di-chorionic sub-group.
Results
The absolute risk of placenta previa, placenta accreta, placental abruption, gestational hypertension, and preeclampsia are significantly higher in the IVF group than in the non-IVF group. While there are no significant differences in the absolute risk of abnormal placenta morphology, fetal distress, FGR, and preterm birth between the two groups. After we did further analysis on the dichorionic sub-group, we found the absolute risk of preterm birth was also higher in the IVF group than in the non-IVF group.
Conclusions
Twin pregnancies who received IVF treatment have a higher risk for most kinds of placenta abnormalities and placenta-related complications. Whether these risks have any further impact on maternal and fetal health needs further investigation.