LONDON – Endometrial ovarian cysts do not reduce the rate of spontaneous ovulation and the potential ability of women to conceive, according to a prospective observational study.
Dr. Umberto Leone Roberti Maggiore of San Martino Hospital and the University of Genoa (Italy) reported the results of a study comparing the healthy and affected ovaries of 214 women with endometriosis. The overall rate of spontaneous ovulation was similar for affected and healthy ovaries over the course of six ovulatory cycles, at 50.3% vs. 49.7% (P = .919).
A total of 1,311 ovulatory cycles were examined during the study, with similar rates of ovulation observed regardless of the side, number, or size of endometriomas, he reported at the annual meeting of the European Society of Human Reproduction and Embryology.
Sara Freeman/IMNG Medical Media
Dr. Umberto Leone Roberti Maggiore
"Over the last years, great attention has been given to the impact of endometriomas on ovarian physiology," Dr. Maggiore said. "Different studies have investigated whether the presence of endometriomas affect ovarian reserve and the outcome of assisted reproductive technologies."
Data from one study in particular suggested that the presence of endometriomas reduced the rate of spontaneous ovulation (Hum. Reprod. 2009;24:2183-6).
"The objective of the current study was to investigate the rate of spontaneous ovulation between the healthy and the affected ovary in women with unilateral endometriomas," Dr. Maggiore explained. Women were recruited into the study at an academic referral center between September 2009 and June 2013. For inclusion, they had to have ultrasound-confirmed endometrioma(s) of a single ovary of 20 mm or more in size, regular menstrual cycles (24-35 days), and a desire to conceive a child.
Women were excluded if they had previous adnexal surgery, had used hormonal therapies in the past 3 months, were pregnant or had breastfed their infants in the past 6 months, had a history of infertility, or had diagnoses of any of the following: hydrosalpinx, pelvic inflammatory disease, polycystic ovary syndrome, thyroid disorders, or psychiatric disturbances.
Transvaginal ultrasound was used to assess the side, number, largest diameter, and volume of the endometriomas. Ovarian reserve was assessed by measuring levels of anti-Müllerian hormone and basal follicle-stimulating hormone. The level of CA-125 was also measured.
The mean age of recruited women was 34 years; 55% of women had endometriomas of the right ovary, the majority (81.1%) had only one endometrial cyst, with 15.2% having two and 3.7% having three endometriomas. The largest diameter of the endometriomas at baseline was a mean of 4.5 cm, with 55.5% of women having a cyst equal to or greater than 4 cm and 15.1% a cyst equal to or greater than 6 cm. The total volume of endometriomas in the same ovary at baseline was a mean of 54.9 cm2.
In terms of pregnancy outcomes, 43% of women conceived during the study period. Of these 63.8% were at term, 20% of patients had an ongoing pregnancy, 3.8% had been delivered preterm, 1.9% voluntarily terminated their pregnancy at the second trimester, and 10.5% had miscarriages.
No correlation was found between levels of follicle-stimulating hormone, anti-Müllerian hormone, or CA-125 and the total endometrial volume, the largest diameter of the endometrioma, or the number of endometriomas. However, the size and volume of the endometriomas by the sixth ovarian cycle were seen to increase from baseline values by a respective 3.9% and 8.1% (both P values less than .001).
Dr. Maggiore reported that 40.2% of women had a 0.1%-5% increase in the total volume of endometriomas over the course of the study, with 29.1% experiencing a volume increase of 5.1%-10%, a further 19.7% a volume increase of 10.1%-25%, and 4.7% an increase of 25.1% or more. Only 6.3% of women experienced a decrease in total endometrioma volume.
"Normal ovulatory function and the potential decrease of ovarian reserve should be considered before suggesting the surgical treatment of endometriomas," said Dr. Maggiore. While surgical removal of these cysts might not be necessary purely to improve fertility, it is too early to say if they will change practice.
"I think [the study] shows that the mere presence of endometrioma is not sufficient to operate," Dr. Thomas D’Hooghe of the Leuven (Belgium) University fertility center said in an interview.
However, Dr. D’Hooghe, who was not involved in the study, noted that an increase in endometrioma volume within 6 months of observation was not an insignificant finding. "If you extrapolate that to say 1 year or 2 years after baseline, there may be a larger increase in volume. ... The endometrioma may rupture and cause adhesions" at that point, he said.