FRIDAY, May 3 (HealthDay News) -- Women taking birth control
pills with lower amounts of estrogen -- a commonly prescribed
contraceptive -- may be at higher risk for chronic pelvic pain and
pain during orgasm, according to new research.
A study of nearly 1,000 women found that women on the lower-dose
oral contraceptives were more likely than those on the standard
dose (with higher estrogen levels), or those not on the pill, to
report pelvic pain.
"In our practice, we have seen a lot of this anecdotally," said
Dr. Nirit Rosenblum, assistant professor of urology at NYU Langone
Medical Center in New York City, a specialist in female pelvic
medicine and reconstructive surgery.
To investigate the potential link further, she compared pain
symptoms of women on low-dose birth control pills with those not on
pills and those on standard doses.
She is scheduled to present the findings Tuesday at the American
Urological Association's annual meeting in San Diego, but
acknowledged additional research is needed to understand the
For her study, Rosenblum defined low-dose birth control pills as
those that contain less than 20 micrograms (mcg) of synthetic
estrogen. (The name often includes the word "lo.") Those that have
20 mcg or more are "standard" or normal dose.
When natural estrogen production declines at menopause, women
can begin to experience pelvic pain, Rosenblum said.
To see if low-estrogen birth control pills might mimic those
effects, she evaluated the online survey responses of 932 women,
aged 18 to 39, associated with two large universities. Women with a
history of pelvic pain, the painful pelvic condition endometriosis
or any who were pregnant were excluded from the study.
Women reported if they were on the pill or not and which dose
pill. Of the 327 women taking birth control pills, about half used
a low-dose pill. The other 605 women did not take the pill.
The women answered questions about pain. Twenty-seven percent of
those on a low-dose pill had pelvic pain symptoms or reported
chronic pelvic pain compared to 17.5 percent of those not on the
Those on normal-dose pills were less likely to have pelvic pain
overall than those not on the pill, she found.
Low-dose pill users were twice as likely to report pain during
or after orgasm than those not on the pill: 25 percent versus 12
percent. Those on higher-dose pills reported no difference in pain
at sexual climax than those not using birth control pills.
Dr. Christopher Payne, a professor of urology at Stanford
University School of Medicine and director of its division of
female urology, said the information could be helpful. However, "I
don't know if we can draw any conclusions from this," he added.
"You can only say there is an association [between the low-dose
pills and pelvic pain]," he said. "You can't say it's cause and
However, "it's certainly something people should be
knowledgeable about," he added. The proposed mechanism -- that the
lower estrogen somehow is linked with the pain -- is plausible, he
"We have observed people who have bladder pain say they often
have flare-ups in the premenstrual period, which is the lowest
estrogen level of the whole menstrual cycle," Payne said. However,
some women also report pain in other parts of the cycle, he
"This information could help clinicians be aware there could be
a connection between a woman's hormone level and her hormone
therapy and their pain," Payne said.
However, he and other pain specialists see a subgroup of women
-- those who have pain problems. Many women on the low-dose pills
could be experiencing no problems at all with the lower estrogen
levels, Payne said.
Women using low-dose pills who do experience pain might ask
their doctor about switching to another contraceptive or using a
higher dose, Rosenblum said. However, higher-dose pills are linked
with other risk factors, such as blood clots and strokes, so women
should discuss the pros and cons with their doctor.
The data and conclusions of research presented at medical
meetings should be viewed as preliminary until published in a
To learn more about pelvic pain, visit the
U.S. National Institutes of Health.