Unilateral oophorectomy (UO), removal of one ovary, is performed in various clinical situations to treat malignant or benign ovarian tumors, ovarian cysts, endometriosis, tubo-ovarian abscess, and ovarian torsion. Many studies have implied a negative impact of UO on ovarian sensitivity.
Whether women’s fertility is affected by removing one ovary has been subject to inconclusive data. There is no clear data to indicate whether UO is detrimental to the pregnancy rate or live birth rate.
A new study at Karolinska Institutet in Sweden quantified the effect of unilateral oophorectomy on live birth and pregnancy rates in women undergoing in vitro fertilization (IVF).
The study found that women who had done UO are less likely to become after IVF and give birth to fewer babies than women with both ovaries. Scientists reached this conclusion after conducting an extensive meta-analysis.
Kenny Rodriguez-Wallberg, adjunct professor at the Department of Oncology-Pathology, Karolinska Institutet, said, “Our meta-study shows that a successful IVF outcome was less likely in women that have only one ovary, compared with women with both intact ovaries. We have been able to show, for the first time, that the surgical removal of an ovary has an adverse effect on fertility.”
For this study, scientists reviewed published studies to compare their results against their point of inquiry. They studied more than 3,000 papers on the subject, of which 18, published between 1984 and 2018, met their criteria and were selected for the final analysis.
Taken together, the papers included 1,057 IVF attempts for women with one ovary and 45,813 for women with two. Five of the studies were included in the analyses of live births, 15 in the analysis of pregnancy rate.
They found that- women with one ovary had a 30 percent lower chance of getting pregnant or giving birth than in the group of women with both ovaries.
Kenny Rodriguez-Wallberg said, “We need to realize the consequences on the fertility of removing one ovary. Sometimes, the operation is necessary, in the event, say, of a malignant tumor. Still, it’s important to improve the information we give to women about what it can mean for their chances of having future children. Given that the biological reserve of eggs is already limited, we should, in some cases, also offer these women the opportunity to freeze their eggs ahead of an oophorectomy.”
Scientists now want to examine if UO has any other health effects, such as the impact of reduced hormone production on the development of other diseases.
The study was financed by the Swedish Research Council, the Swedish Cancer Society, the Swedish Childhood Cancer Foundation, the Cancer Research Funds of Radiumhemmet, and Region Stockholm.
- Kenny A. Rodriguez-Wallberg et al. Live birth and pregnancy rates after in vitro fertilization/intracytoplasmic sperm injection in women with previous unilateral oophorectomy: a systematic review and meta-analysis. DOI: 10.1016/j.fertnstert.2022.01.033