P–310 Women with endometriosis achieve live birth after a similar number of embryo transfers independent of the endometriosis subtype
Authors: Koh. Schwartz A , Vidal A , Fritsche L , Nirgianakis K , Vo. Wolff M , Mitter V 
Published: August 2021

Abstract

Study question
How many embryo transfers are needed to achieve the first live birth in women with endometriosis depending on disease localisation?

Summary answer
The number of transfers needed to achieve live birth in women with endometriosis is independent from the disease’s subtype.

What is known already
Infertility is one of the leading symptoms in women with endometriosis. Endometriosis is also known to negatively impact in-vitro fertilization (IVF) outcome. A reduction of oocyte yield, especially of mature oocytes in women with endometrioma (OMA) and deep infiltrating endometriosis (DIE) has been shown. Inflammatory processes possibly affect folliculogenesis and oocyte development, maybe impeding embryo development and implantation. In contrast, even with fewer retrieved oocytes per cycle live birth rate was not affected. However, it is currently unknown if specific endometriosis subtypes could differentially affect IVF success. This would be relevant for a more targeted counseling regarding the treatment success.

Study design, size, duration
This is a single-center cohort study including women (N = 229) with embryo transfer cycles leading to live birth at the Bern University Hospital between 2010 and 2017. We only included women until they achieved the first live birth at our center. Participants/materials, setting, methods: We included 86 women with endometriosis and 143 women with male factor infertility serving as comparison group. We collected patient characteristics, details from the endometriosis surgery and reproductive treatment and outcomes from medical reports. We hierarchically classified the dominant endometriosis localizations as follows: deep infiltrating endometriosis (DIE, N = 21) &gt; ovarian endometriosis (OMA, N = 35) &gt; superficial peritoneal endometriosis (SUP, N = 30). We compared the number of embryo transfers needed to achieve a live birth.

Main results and the role of chance
Women with endometriosis were older (34.5 ± 3.9 years) than women from the control group (33.4 ± 3.9), p = 0.03. Body-mass-index, previous parity or Anti-Mullerian hormone level did not differ between the groups SUP, OMA, DIE or the comparison group. The number of necessary embryo transfer cycles to achieve a live birth did not differ between women with SUP (3.4 ± 2.6 embryo transfers), OMA (2.9 ± 2.0), DIE (3.0 ± 2.4) and the comparison group (2.9 ± 2.2), p = 0.59. IVF is beneficial in women with endometriosis, especially when OMA and/or DIE affect mobility of tubes and ovaries and spontaneous pregnancy is unlikely or impossible. This could account for the equal number of transfer cycles needed to achieve a live birth in women with OMA compared to the comparison group, even though the women with endometriosis were of older age. This is reassuring when counseling women with endometriosis.

Limitations, reasons for caution
We did not calculate cumulative pregnancy rate per cycle, because in Switzerland IVF treatment is at the patient’s own cost and therefore biased. We wanted to include all women with endometriosis, so fresh and thawing cycles were included. Women from the comparison group had no surgical exclusion of endometriosis.
Wider implications of the findings: Our study suggests that the endometriosis subtype does not determine the embryo transfer success rate after IVF and therefore is less relevant for counseling. Individualized anti-inflammatory treatment before embryo transfer might positively affect the cycles’ outcome. Studies with a larger sample are required to be more conclusive on this issue.

Trial registration number
BASEC 2015–00235