• By Cara Murez HealthDay Reporter
• Posted October 3, 2022

Study Counters Myth That Contraceptive Pill Enlarges Breasts in Teen Girls

Birth control pills that contain both estrogen and progestin do not contribute to growth of enlarged breasts in teens and young women, a new study finds, and may actually be associated with developing less severe breast enlargement.

Moreover, the combination pills don't increase the risk of regrowth after breast-reduction surgery, said researcher Dr. Brian Labow and colleagues. Labow is with Boston Children's Hospital and Harvard Medical School.

The study is published in the October issue of Plastic and Reconstructive Surgery.

"Despite the positive benefits of COCs [combined oral contraceptives], many patients, parents, and providers worry that their use may worsen breast hypertrophy in adolescents," Labow and his co-authors said in a journal news release.

Sometimes breast reduction surgery is done to reduce pain and psychosocial problems in teenagers and women who have enlarged breasts, or macromastia, the study explained. In this same age group, the combination "Pill" may be prescribed as a contraceptive or to manage acne, menstrual abnormalities, endometriosis or polycystic ovary syndrome.

The contraceptives can cause fluid retention and breast tenderness or swelling.

To study whether they also contributed to enlargement, the researchers assessed 378 patients, ages 12 to 21, who were undergoing breast reduction surgery at Boston Children's Hospital.

Severity of enlargement was compared for patients who did and did not use the combination pills or other hormonal contraceptives, along with breast regrowth in the first year after reduction surgery.

Doctors compared the findings with those in a control group of 378 patients of similar age.

Patients with enlarged breasts had lower use of hormonal contraceptives overall, 38% compared to 65%. Among women taken contraceptives, those with enlarged breasts were more likely to be prescribed the combination Pill, 83% compared to 53%.

However, using those contraceptives did not seem to affect the severity of breast enlargement, researchers found.

The median amount of breast tissue removed during the reduction surgery was similar between groups, according to the study. It was actually somewhat less in patients who used combination birth control pills, compared to those with no hormonal contraceptive use.

Scores for pain and other symptoms of severely enlarged breasts, including irritation of the breast skin, difficulty exercising or problems finding clothes that fit, were similar between groups.

Two years later, researchers found no significant difference in the rate of breast regrowth between patients who did and did not use the combination pills.

About 5% of patients had postoperative breast regrowth. About half of cases were due to regrowth of the breast gland, rather than associated with weight gain, according to the study.

The team also found no increased risk of breast regrowth for women who used the combo pills after breast reduction surgery.

"Although additional research is needed, providers are encouraged to consider COCs when prescribing [hormonal contraceptives] for their patients with macromastia when indicated and appropriate," the researchers said.

More information

The U.S. National Library of Medicine has more on breast reduction.

SOURCE: Plastic and Reconstructive Surgery, news release, Sept. 29, 2022