According to a study published in JAMA Network Open, twin pregnancies after in vitro fertilisation (IVF) and advanced maternal age are independently associated with adverse obstetric outcomes, and their coexistence may aggravate the obstetric risk.


The analysis included 16,879,728 pregnant women aged 20 to 49 years. The researchers analysed 16 obstetric outcomes among women with twin or singleton pregnancy, with or without IFV. Among the obstetric outcomes, 10 were related to maternal complications and the remaining six were neonatal complications.


The results show that the twin pregnancy rates were 32.1 per cent in the IVF group and 1.5 per cent in the non-IVF group. The most common adverse obstetric outcomes after pregnancy conceived with IVF were caesarean delivery (88.8%), low birth weight (43.8%), preterm birth (39.6%), gestational diabetes (20.5%), gestational hypertension, preeclampsia and eclampsia (17.5%), dystocia (16.8%), and postpartum haemorrhage (11.9%).


The analysis also showed that most curves of obstetric risks had an upward trend with increasing maternal age, especially among women older than 35 years.


These findings provide valuable evidence for clinical decision-making and public health policies, the authors say. Promoting the elective single embryo transfer strategy may improve outcomes after IVF by reducing twin pregnancies.