A new study, presented at the 2019 annual conference of the Radiological Society of North America, has found that women who use birth control pills may have a smaller hypothalamus, a small, key area in the brain that controls the nervous and endocrine (hormonal) system.
In the United States, nearly 13 percent of women between the ages of 15 and 49 take birth control pills for a wide range of conditions, such as irregular menstruation, polycystic ovary syndrome, endometriosis, acne, and menstrual cramps.
The birth control pill began as a way of “preventing pregnancy using hormone control.” It was originally developed to stop ovulation through the female hormone progesterone but it has now been used for a variety of conditions. Some women use it to skip menstruation or stop it completely.
Previous studies have found little or no evidence suggesting the impact of birth control pills on the hypothalamus.
The hypothalamus is a vital organ that produces hormones and helps control a wide range of bodily functions, such as mood, sex drive, sleep cycles, appetite, body temperature, and even heart rate.
Michael Lipton of Albert Einstein College of Medicine said, “There is a lack of research on the effects of oral contraceptives on this small but essential part of the living human brain.”
Lipton told Medical News Today that his team’s previous work inspired them to investigate the effects of birth control pills on the hypothalamus.
“We have reported some quite interesting findings on sex-based risk in brain injury,” he said. “Specifically, women seem to fare worse than men. Other studies have shown that the female sex hormone progesterone is neuroprotective”
“Since [oral birth control pills] are widely used, we wanted to explore the effects of [oral contraceptive pills] in healthy women to understand their potential role in our sex-divergent findings. The finding we report here is one outcome from that exploration,” he continued.
The researchers found a dramatic difference in the hypothalamus size in women who used oral contraceptive pills.
Lipton said, “I was not expecting to see such a clear and robust effect. We found a dramatic difference in the size of the brain structures between women who were taking oral contraceptives and those who were not.”
Of 50 healthy women participated in the study, 21 were on birth control pills. The researchers looked at the MRI brain scans of all of the women.
“We validated methods for assessing the volume of the hypothalamus and confirm, for the first time, that current oral contraceptive pill usage is associated with smaller hypothalamic volume,” said Lipton.
The team found that the women who were using birth control pills had a significantly smaller hypothalamus than women who were not using the pills.
“These findings are generally consistent with previous studies of [oral contraceptive pills] that support [an effect] on mood regulation. Our findings might represent a manifestation of the mechanism behind these effects or simply be unrelated. It is just too soon to tell,” added Lipton.
He concluded, “This initial study shows a strong association and should motivate further investigation into the effects of oral contraceptives on brain structure and their potential impact on brain function.” Talking about the future plans, Lipton said, “For my group, the most important and immediate goal is to incorporate the role of [oral contraceptive pills] into our ongoing studies and to further explore the role of normal sex hormone cycles related to the menstrual cycle, as well as the role of androgens (testosterone) in men and women.”