Risk of cesarean section in singleton pregnancies after assisted reproductive techniques

OBJECTIVE: To evaluate the perinatal outcome of singleton pregnancies after assisted reproductive techniques in comparison with that in matched controls from spontaneous pregnancies. STUDY DESIGN: A total of 11,776 deliveries from January 1, 1995, to May 31, 2001, were subjected to retrospective analysis. Data on 259 neonates from singleton pregnancies after ovulation induction (n = 85, 32.8%), intrauterine insemination (n = 17, 6.6%) or in vitro fertilization (n = 157, 60.6%) were evaluated. The pregnancy outcome was compared with that for controls (n = 518) matched for age, gravidity and parity after spontaneous pregnancies. RESULTS: Cesarean section was significantly more frequent in the study group than in the control group (42.1% vs. 27.6%, P < .001, odds ratio OR] 1.91, 95% confidence interval CI] 1.39-2.61). The prevalence of preterm deliveries was not significantly higher (P = .40, OR 1.23, 95% CI .78-1.95) in the study group as compared with the controls (12.7% vs. 10.6%). There was no significant difference in intrauterine growth retardation between the two groups (9.3% vs. 6.2%, P = .14, OR 1.55, 95% CI .89-2.69). CONCLUSION: Singleton pregnancies after assisted reproductive techniques are associated with an increased rate of cesarean section, whereas neonatal outcome is not influenced.