In vitro fertilisation in Sweden: obstetric characteristics, maternal morbidity and mortality.

OBJECTIVE

To investigate obstetric characteristics, maternal morbidity and mortality among Swedish women giving birth after in vitro fertilisation (IVF) treatment.

DESIGN

Register study.

SETTING

Nationwide study in Sweden.

SAMPLE: All women known to have had IVF in Sweden 1982-2001.

METHODS

Using Swedish health registers, women who had given birth after IVF were identified from all Swedish IVF clinics and compared with all women who gave birth. Analysis was performed with the Mantel-Haenszel technique.

MAIN OUTCOME MEASURES: Diagnoses during pregnancy, at delivery and at re-admission within 60 days after delivery and risk of cancer.

RESULTS

IVF women had an increased risk of bleeding in early pregnancy [odds ratio (OR) = 4.59, 95% confidence interval (95% CI) 4.08-5.15] and of ovarian torsion during pregnancy (OR = 10.6, 5.69-10.7). They were also more likely to encounter pre-eclampsia (OR = 1.63, 1.53-1.74), placental abruption (2.17, 1.74-2.72), placenta praevia (3.65, 3.15-4.23), bleeding in association with vaginal delivery (1.40, 1.38-1.50) and premature rupture of membranes (PROM) (2.54, 2.34-2.76). Interventions including caesarean sections (1.38, 1.32-1.43) and induction of labour (1.37, 1.29-1.46) in singleton pregnancies was more frequent. The type of IVF method had little effect on these results, but there was a tendency for women who had received intra-cytoplasmatic sperm injection (ICSI) to have slightly fewer complications than women having standard IVF. There was a significant decrease in cancer risk after IVF (0.79, 0.69-0.91) but a suggested increase in the risk of ovarian cancer both before (2.70, 1.49-4.91) and after (2.08, 1.15-3.76) IVF. No change in mortality was observed.

CONCLUSIONS

Women treated with IVF had an increased obstetric morbidity. This seems to contribute little to the well-known increased risk of preterm delivery.