Risk of hypertensive disorders of pregnancy in electively induced or expectantly managed full-term IVF pregnancies.

RESEARCH QUESTION: Are there differences in the rates of hypertensive disorders of pregnancy among IVF patients who underwent induction of labour at 39 weeks compared with those who were managed expectantly?

DESIGN

This was a retrospective cohort study of 1176 low-risk singleton pregnancies conceived via IVF with no contraindications to vaginal delivery. Two groups were constructed: elective induction of labour from 39 weeks 0 days to 39 weeks 6 days (n = 234); and expectant management (n = 942). The main outcome measure was the incidence of hypertensive disorders of pregnancy. The secondary outcome was the rate of caesarean delivery. Subanalyses were performed within fresh and frozen embryo transfer groups.

RESULTS

Hypertensive disorders of pregnancy developed in 8.1% of patients in the induction of labour group and in 12.4% of patients in the expectant management group (P = 0.06). This difference was attenuated after controlling for potential confounders (P = 0.28). For frozen embryo transfers, the unadjusted odds of hypertensive disorders of pregnancy were significantly lower for the induction of labour group compared with the expectant management group (P = 0.02), and after adjusting for confounders, the OR lost significance (P = 0.09). For fresh embryo transfers, there was no difference in the odds of hypertensive disorders of pregnancy between the two groups. The odds of delivering via caesarean section were higher in the induction of labour group, in the total population (P < 0.001) and in subanalyses (P ≤ 0.03).

CONCLUSION

Overall, in IVF-conceived pregnancies, induction of labour was not associated with lower incidence of hypertensive disorders of pregnancy compared with expectant management. However, induction of labour was associated with a higher rate of caesarean delivery.