Combined and progestin-only pills (POPs) are effective in reducing pelvic pain related to endometriosis, such as menstrual pain, chronic pelvic pain and sexual pain, as well as increasing quality of life in women from this disabling disease, according to a systematic review, the first ever published about this important topic.
“Some of these contraceptives, but only combined, have also been proven efficacious in reducing the risk of postsurgical relapse of endometriomas,” said principal investigator Giovanni Grandi, MD, an associate researcher in ob/gyn at the University of Modena and Reggio Emilia in Italy. “However, there is insufficient evidence to reach definitive conclusions about the overall superiority of any particular hormonal contraceptive.”
For the review, published in The European Journal of Contraception and Reproductive Health Care, Medline, PubMed and Embase databases were searched to identify all published English language studies on hormonal contraceptive therapies in women with a validated endometriosis diagnosis, in comparison to placebo, comparator therapies or other hormonal treatments.
Published literature spanned from January 1987 to March 2018. A total of 28 studies met the inclusion criteria for the required number of participants, interventions, comparators, outcomes and study design.
“Endometriosis is a common disease, affecting about 10% of the female population, but it is not always associated with infertility,” Dr. Grandi told Contemporary OB/GYN. “Many of the women impacted during reproductive age want to take an effective hormonal contraceptive to avoid unintended pregnancies. Our aim was to discover if there was any evidence to suggest one hormonal contraceptive in particular as a first choice for these women.”
Combined hormonal contraceptives and POPs were associated with clinically significant reductions in dysmenorrhea and were often accompanied by reductions in non-cyclical pelvic pain and dyspareunia, along with improved quality of life.
However, only two combined oral contraceptive (COC) preparations – ethinylestradiol/norethisterone acetate and a flexible ethinylestradiol/drospirenone regimen – significantly increased efficacy compared to placebo.
Moreover, only three studies concluded that postoperative use of COCs reduced risk of disease recurrence, and there was no evidence that POPs decreased risk of recurrence.
“There are few data in the literature about hormonal contraception pills being widely used in clinical practice,” Dr. Grandi said. “For example, there is scant literature about combination ethinylestradiol/levonorgestrel, whereas there is more data about intrauterine systems releasing 52 mg of levonorgestrel alone.”
Dr. Grandi and his colleagues were surprised that the most studied progestin-only contraceptive is the 52-mg levonorgestrel-releasing intrauterine system (LNG-IUS), citing that an advantage of the system is that medical treatment can continue for up to 5 years. “The device is also easy to remove, the cumulative costs are low and the systemic progestin dose is low,” Dr. Grandi said.
On the other hand, there is risk of menstrual irregularities and spontaneous expulsion, plus ovulation is not consistently inhibited.
Dr. Grandi said more research is needed on the "window of opportunity": the serum level of estradiol in women with endometriosis. “This level changes dramatically, based on the different hormonal treatments,” he said. “We must understand which treatment is best for these patients.”
The review provides clinicians a tool to critically evaluate evidence from today’s literature, “before prescribing a specific hormonal contraceptive to one of their patients with endometriosis who does not desire pregnancy,” Dr. Grandi said.
Besides the need to study in detail the most suitable medical therapy for a specific patient with endometriosis, “we need to understand and avoid the possible side effects of hormonal contraceptives that often result in discontinuing treatment,” Dr. Grandi said.
Dr. Grandi reports no relevant financial disclosures.