Obstetric outcome of women with in vitro fertilization pregnancies hospitalized for ovarian hyperstimulation syndrome: a case-control study

ObjectiveTo evaluate the obstetric outcome of women with IVF pregnancies hospitalized for ovarian hyperstimulation syndrome (OHSS).DesignA case-control study.SettingDepartment of Obstetrics—Gynecology and Reproductive Medicine.Patient(s)All IVF patients hospitalized for OHSS with a positive pregnancy test matched to an IVF pregnancy control group who did not develop OHSS.Intervention(s)Retrospective study of all clinical and laboratory data.Main Outcome Measure(s)OHSS morbidity, early pregnancy outcome, and obstetric complications.Result(s)The incidence of OHSS requiring hospitalization was 1.14% among 3,504 IVF cycles. Forty patients (31 singletons, 8 twins, and 1 triplet) hospitalized for severe OHSS with a mean duration of hospitalization of 10.2 ± 7.2 days were compared with a control group of 80 IVF pregnancies (48 singletons, 15 twins, and 2 triplets). Early OHSS occurred in 22.5% of patients, and late OHSS in the remaining 77.5% patients. In the OHSS group, 10% had thromboembolic complications. The miscarriage rate was similar for the OHSS group and the control IVF group (17.5% vs. 16%). Concerning ongoing clinical pregnancies, pregnancy-induced hypertension (PIH) and preterm labor were significantly higher in the OHSS group (respectively, 21.2% vs. 9.2% and 36% vs. 10.7%). In the subgroup of singletons, PIH was significantly higher for OHSS pregnancies than for controls.Conclusion(s)Pregnancies after IVF and OHSS are associated with a greater risk of adverse obstetric outcome.