Abstract
Study question
Does the presence of endometrioma during ovarian stimulation affect blastulation and clinical pregnancy rates (CPR)?
Summary answer
Blastulation rates were similar in women with endometrioma compared to women without. Likewise, CPR were comparable.
What is known already
Although relationship of endometriosis and subfertility is well-established, its mechanism is still under investigation. Decreased oocyte quality, resulting from anatomical and/or inflammatory factors is one of the prominent culprits. Most studies regarding endometriosis and oocyte quality are highly heterogeneous and effect of endometriosis on oocyte quality is yet to be determined. Blastulation is thought as a surrogate marker for oocyte quality. Thus, it may be possible that detrimental effect of the presence of endometrioma during ovarian stimulation can be indirectly assessed by blastulation.
Study design, size, duration
Records of all women who underwent assisted reproductive technology treatment at Koc University Hospital Assisted Reproduction Unit between 2016 and October 2020 were screened for this retrospective study. All women who had endometrioma(s) during ovarian stimulation were included in the study group (EG) (n = 71). They were matched with women diagnosed with tubal factor or unexplained infertility who underwent oocyte pickup within the same period to form the control group (CG) (n = 104).
Participants/materials, setting, methods
All women underwent antagonist or long protocol. All embryos were cultured until blastocyst stage regardless of the number of oocytes or embryos available. Size/location of endometriomas, number of oocytes retrieved, number of available blastocysts, positive pregnancy test per cycle and clinical pregnancy rate per cycle were recorded. Blastulation rate was calculated as number of available blasts divided by the number of metaphase-II oocytes. Embryos were transferred in a fresh or artificially prepared frozen-thawed cycle.
Main results and the role of chance
There were 71 women in EG and 104 women in CG, which included 30 women with tubal and 74 with unexplained infertility. Median endometrioma size was 26 mm(22–33). Twenty-three patients in EG had history of endometrioma excision (31.3%). Median age [35.0 years (31.0–39.0) vs 34 (32.0–36.0), p = 0.26] and serum AMH levels [1.8 (1.1 - 4.2) vs 2.3 (1.3 - 3.7) ng/dL, p = 0.91] were similar in EG and CG, respectively. Body mass index in kg/m2 [21.8 (20.2–24.6) vs 24 (21.5–27.9), p < 0.01] and infertility duration in years [2 (1–2.6) vs 3 (2–5), p < 0.01] were significantly lower in EG. Number of retrieved oocytes [8 (5–12) vs 12 (7–15.8), p < 0.01)] and metaphase-II oocytes [6 (4–10) vs 8.5 (6–12), p < 0.01] were lower in EG group compared to CG group. However, blastulation rate per MII oocyte were similar between the EG and CG [(0.25 (0.20–0.41) vs 0.30 (0.14–0.50), respectively, p = 0.58]. Adjusted analysis for age and number of MII oocytes revealed similar finding.
Positive pregnancy test per cycle was similar at 53.5% vs 61.5% in EG and CG, respectively (p = 0.3). CPR were similar between the EG and CG (45% vs 58%, respectively, p = 0.10).
Limitations, reasons for caution
Retrospective design, lack of live birth information are the main limitations of our study.
Wider implications of the findings: Presence of endometrioma during ovarian stimulation does not seem to adversely affect blastulation rates. While this is reassuring regarding oocyte quality, further research is required to assess its effect on live birth.
Trial registration number
Not applicable
Can Time-Lapse Incubation and Monitoring Be Beneficial to Assisted Reproduction Technology Outcomes? A Randomized Controlled Trial Using Day 3 Double Embryo Transfer