Women who underwent surgery for ovarian endometriosis may respond poorly to ovarian hyperstimulation during assisted reproductive technology, or fertility treatment, according to the results of an observational study.
However, pregnancy and live birth rates were unaffected.
The study, “Endometriosis and ART: A prior history of surgery for OMA is associated with a poor ovarian response to hyperstimulation” was published in the journal PLOS One.
Infertility is one of the consequences of endometriosis, with women often requiring assisted reproductive technology (ART). The presence of ovarian endometriomas, a benign, estrogen-dependent cyst found in women of reproductive age, has been suggested to have a negative impact on ovarian stimulation, one of the steps commonly used during fertility treatment.
The processes underlying these impairments remain unclear.
Researchers evaluated the impact of ovarian endometrioma to ovaries’ response to hyperstimulation in ART. They conducted a large observational study that included 201 infertile women with ovarian endometrioma — in 108 women affecting only one ovary — who underwent fertility treatment.
The study also included 402 healthy women also undergoing ART (the control group).
Participants of both groups were matched for age and blood levels of the anti-Mullerian hormone (AMH), previously suggested as a predictor of the response in controlled ovarian hyperstimulation.
Researchers aimed to identify risk factors for a poor ovarian response to hyperstimulation in women with ovarian endometriomas undergoing in vitro fertilization and compare their success to women without endometriosis undergoing ART.
Poor ovarian response to ovarian stimulation was defined as a cycle that failed to complete, or by a low (less than three) collection of oocytes (immature eggs) in response to the ovarian stimulation protocol.
The results showed the response of ovaries to hyperstimulation used in ART was significantly reduced in women with ovarian endometriosis. Poor ovarian response was higher in this group, 30.8%, than in the control group, which was 22.3%.
Despite these differences, the pregnancy and live birth rates showed no statistical significant differences between both groups — 35% vs. 41.3% (pregnancy; ovarian endometriosis group) and 25.8% vs. 30.5% (live birth; control group).
Researchers also tried to identify potential risk factors for a poor ovarian response to hyperstimulation. They found that patients who had a prior surgical intervention for ovarian endometrioma had a significantly higher risk of poor ovarian response.
Also, women who were older than 35 with AMH levels below 2 ng/ml were also independent risk factors for increased risk of a poor ovarian response.
“Our findings have clinical implications that are of relevance to daily practice,” researchers wrote.
While the presence of ovarian endometriosis limits the number of oocytes, it seems to have no impact in the outcomes of pregnancies, as the “live birth rates were similar for the women with OMA [ovarian endometrioma] as compared to their disease-free counterparts.”
“For women who do not intend to become pregnant in the near future but who are scheduled to undergo surgery for OMA [ovarian endometriosis], fertility preservation could be a suitable option prior to the surgery in order to limit the risk of a [poor ovarian response] after the surgical treatment,” researchers wrote.
“Our results therefore support the notion that fertility preservation should be part of the preoperative advice that is provided to young women with severe endometriosis,” the study concluded.