A comparison of the ovarian response to external stimulation between women with right or left ovary participating in programs of ICSI/ET

Biological Impact of Unilateral Oophorectomy: Does the Number of Ovaries Really Matter?

Although unilateral oophorectomies are performed more often than bilateral ones in women of reproductive age, their clinical consequences have been less intensively investigated. Experimental models in animals have shown that compensatory mechanisms occur after a unilateral oophorectomy (UO). This review aims to summarize the available evidence on the biological effects of unilateral oophorectomy on women. Evaluated outcomes include age at onset of menopause, risk of cardiovascular and neurological disease, risk of mortality and fertility outcome after spontaneous conception or in vitro fertilization (IVF). Results were compared with findings reported after bilateral oophorectomy and/or ovarian excision and/or women with intact ovaries. An electronic database search was performed using PubMed and Scopus, followed by a manual search to identify controlled studies that compared women after UO with women with two intact ovaries. In particular, a systematic review of fertility outcomes after IVF was performed, and the data were summarized in a table. Women who underwent UO had a similar age at menopause and similar clinical pregnancy rate compared to women with two ovaries. However, decreased ovarian reserve affecting the quantity but not the quality of the ovarian pool after IVF was observed in the UO group. Furthermore, an increased risk of neurological disease and even an increased risk of mortality was observed in women with single ovary. These data need to be confirmed by further studies, and a plausible mechanism of action must be identified. At present, patients who undergo UO can be reassured with regard to their reproductive potential and their age at onset of menopause.

Unilateral oophorectomy results in compensatory follicular recruitment in the remaining ovary at time of ovarian stimulation for in vitro fertilization

OBJECTIVE

To assess the effect of unilateral oophorectomy (UO) by assessing ovarian reserve (OVR) and the response to gonadotropin stimulation in women with UO undergoing in vitro fertilization (IVF) compared with the response of the ipsilateral ovary of women without UO.

DESIGN

Historical cohort study.

SETTING

Academic fertility clinic.

PATIENT(S)

Fifty-one women with single ovary compared with a referent group with both ovaries in a 1:2 fashion.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Day-3 follicle-stimulating hormone (FSH), estradiol, and antral follicle counts as measures of OVR, and IVF outcomes including number of follicles aspirated and oocytes retrieved.

RESULT(S)

The baseline demographics and serum markers of OVR were not different. Referent women had greater follicular yield and oocyte numbers when compared with women with UO; however, when compared with the ipsilateral ovary of the referents, women with UO had a higher antral follicle count and greater follicle and oocyte numbers. In multivariate analyses, the ovary from women with UO was more likely to yield more than the median number of follicles and oocytes than the ipsilateral ovary in referent women. Live-birth rates in both groups were similar.

CONCLUSION(S)

Our results suggest that the remaining ovary appears to compensate in follicular yield after UO in women, confirming the animal data. Women with UO can be reassured and appropriately counseled regarding IVF.