Increased early pregnancy loss in IVF patients with severe ovarian hyperstimulation syndrome

Since severe ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of assisted reproduction, the focus of attention in such cases is placed firmly upon the health of the patient, with the endeavour to achieve a pregnancy being considered of secondary importance. The aim of this study was to focus on the pregnancy rate and pregnancy outcome in IVF patients hospitalized for severe or critical OHSS, in one centre, during a period of 6 years.

We compared the characteristics of patients with severe OHSS: those who conceived with the ones who did not conceive, and among pregnant IVF patients, those with ongoing pregnancies with those that miscarried.

Pregnancy was achieved in 60 of 104 (58%) patients with severe OHSS. Pregnancy continued until delivery in 37 of these 60 patients (62%), whereas the remaining 23 (38%) aborted. The pregnancy and abortion rates in patients with severe OHSS were significantly higher than those of IVF patients without OHSS, during the same time period [23% (1138/4922) and 15% (169/1138) respectively, P < 0.001]. The mean duration of hospitalization for OHSS was significantly shorter in those who delivered compared with those who aborted (5.9 +/- 3.2 versus 10.5 +/- 9.6 days, P < 0.01) and in the non-pregnant patients compared with the pregnant patients (5.2 +/- 3.2 versus 7.6 +/- 6.6 days, P < 0.02).

The clinical pregnancy rate of IVF patients with severe OHSS was significantly higher than that of patients without the syndrome. A longer stay in hospital-reflecting a more severe form of OHSS-was correlated with a higher frequency of abortions. OHSS, necessitating hospitalization, is a detrimental clinical situation not only for the mother but also for the developing pregnancy.