The impact of ovulation induction and ovarian stimulation on the risk of pregnancy-induced hypertension and on neonatal outcomes: A case/control study.

Objectives: To study the role of ovarian stimulation procedures on the risk of pregnancy-induced hypertension, gestational diabetes mellitus and neonatal outcomes according to women's characteristics and the causes of infertility.

Design: Retrospective, observational, case/control study.

Patients: Spontaneous pregnancies (group A, n=8107), pregnancies achieved after mild ovarian ovulation induction without other Assisted Reproductive Technology (ART) procedures (group B, n=44), pregnancies after mild ovarian stimulation and ART procedures (group C, n=53) or pregnancies after multi (>2) follicular stimulation with gonadotrophin therapy and ART procedures (group D, n=133); all of the groups had identical protocols for prenatal care.

Main Outcome Measurements: Pregnancy-induced hypertension (PIH), fetal macrosomia (estimated fetal weight >90th percentile), gestational diabetes mellitus, caesarean section, and neonatal outcomes.

Results: The incidence rates of PIH (2.7, 11.6, 4.2, and 2.5%) in groups A, B, C and D, respectively, (p=0.004), fetal macrosomia (4.7, 7.0, 20.8, and 7.6%, respectively, p<0.001), caesarean section (21.8, 37.2, 21.7, and 17.6%, respectively, p=0.048), differed among the groups. The high incidence of PIH in pregnancies following ovulation induction was driven by polycystic ovarian syndrome (PCOS) per se.

Conclusion: PCOS per se was associated with more PIH, and ART procedures after mild mono/bi follicular ovarian stimulation were associated with more fetal macrosomia.