The impact of unilateral oophorectomy on ovarian reserve in assisted reproduction: a systematic review and meta-analysis

Background: Women following unilateral oophorectomy (UO) are occasionally encountered during assisted reproduction treatment. Objective: To explore the impact of UO on ovarian reserve in assisted reproduction. Search strategy: An electronic database search was performed using PubMed, EBSCO, ISI, Trip, ClinicalTrial.gov and the Cochrane library followed by a manual search to identify published research between January 1978 and December 2015. Selection criteria: Controlled studies that compared infertile women following UO undergoing IVF-ET treatment with women with two intact ovaries. Data collection and analysis: Two reviewers independently extracted the data concerning the impact of UO on ovarian reserve tests, ovarian response to controlled ovarian hyperstimulation and clinical pregnancy rate. Meta-analysis was performed using these measures. Main results: Twenty-one studies were eligible for quantitative analysis. They included 1045 and 18 172 IVF cycles in women with one and two intact ovaries, respectively. Basal FSH weighted mean difference (WMD) was significant (2.01 IU/l; 95% CI: 0.24–3.79, P = 0.026). Similarly, the WMD of serum E ₂ level on the day of hCG administration was significant (WMD: −431 pg/ml; 95% CI: −616 to −246, P < 0.001). However, the weighted overall odds ratio (OR) of clinical pregnancy between women with a single ovary and women with two ovaries was comparable (overall OR: 0.76; 95% CI: 0.57–1.00, P = 0.054). All eligible studies were retrospectively conducted and the heterogeneity among ovarian response measures was high. Conclusions: Available pooled data supports an adverse effect of UO on ovarian reserve involving the quantity but not the quality of the ovarian pool. Tweetable abstract: Review finds women with one ovary removed have less IVF capacity but the same pregnancy rate as women with two ovaries.