Pregnancy and neonatal outcomes following luteal GnRH antagonist administration in patients with severe early OHSS

Do high-risk patients who develop severe early ovarian hyperstimulation syndrome (OHSS) and receive low-dose GnRH antagonist in the luteal phase have lower live birth rates compared with high-risk patients who do not develop severe early OHSS and do not receive GnRH antagonist in the luteal phase?

Low-dose luteal GnRH antagonist administration in women with severe early OHSS is associated with similar live birth rates to that of high-risk patients who do not develop severe early OHSS and do not receive GnRH antagonist in the luteal phase.

It has been reported that luteal GnRH antagonist administration in patients with established severe early OHSS appears to prevent patient hospitalization and results in quick regression of the syndrome on an outpatient basis. However, the effect of such treatment on pregnancy outcome has been investigated in only a small number of animal studies.

This is a prospective cohort study of 192 IVF patients who were at high risk for OHSS and who did not wish to cancel embryo transfer and have all embryos cryopreserved. The study was conducted between January 2009 and December 2011 at Eugonia Assisted Reproduction Unit.

Patients were <40 years of age, with polycystic ovaries, at high risk for OHSS (defined by the presence of at least 20 follicles ≥11 mm on the day of triggering of final oocyte maturation) and not willing to cancel embryo transfer and cryopreserve all embryos, if severe early OHSS was diagnosed by Day 5 of embryo culture. Patients who were diagnosed with severe early OHSS on Day 5 post-oocyte retrieval were administered 0.25 mg of ganirelix for 3 days, from Day 5 until and including Day 7 (OHSS + antag group, n = 22). High-risk patients who did not develop the severe early OHSS did not receive GnRH antagonist in the luteal phase (control group, n = 172). All patients underwent embryo transfer on Day 5.

MAIN RESULTS AND THE ROLE OF CHANCE: Live birth rates (40.9 versus 43.6%), ongoing pregnancy rates (45.5 versus 48.8%), clinical pregnancy rates (50 versus 65.1%), positive hCG (72.7 versus 75%), duration of gestation (36.86 ± 0.90 weeks versus 36.88 ± 2.38 weeks) and neonatal weight (2392.73 ± 427.04 versus 2646.56 ± 655.74 g) were all similar in the OHSS + antag and control groups, respectively. The incidence of major congenital malformations was 2.9% (3/103) in children born in the control group compared with no cases (0/14) in children born following luteal GnRH antagonist administration. No stillbirths or intrauterine deaths, and no cases of pregnancy-induced late OHSS were recorded in either group. None of the 22 patients with severe early OHSS required hospitalization following luteal antagonist administration. Ovarian volume, ascites, hematocrit, white blood cell count, serum estradiol and progesterone decreased significantly (P < 0.001) by the end of the monitoring period (Day 11 post-oocyte retrieval), indicating rapid resolution of the severe OHSS.

This is a prospective cohort investigation with a very limited number of patients receiving the intervention and a larger number of control patients. Our findings suggest that low-dose luteal GnRH antagonist administration during the peri-implantation period may be safe, although larger studies with follow-up of the children born are required.

Our study suggests for the first time that low-dose luteal GnRH antagonist administration in women with severe early OHSS is associated with a favourable IVF outcome, comparable to control high-risk patients without severe OHSS and not receiving the intervention. Regarding the wider implications on the concept of an OHSS-free clinic, administration of GnRH antagonist in the luteal phase may present a tertiary management level in patients with established severe OHSS, along with the use of GnRH antagonist protocols for primary prevention and the replacement of hCG with GnRH agonist for triggering final oocyte maturation for secondary prevention. However, at present, fresh embryo transfer combined with antagonist administration should only be used with caution by experienced practitioners, after carefully deciding which patients can have a fresh transfer or embryo cryopreservation, until the current data are confirmed by larger trials.