A meta-analytic review of 13 studies published in the Journal of Sleep Research explored effects of hormonal contraceptives on sleep patterns in women and found no appreciable changes in women who use these types of contraceptives. The only difference found was that women who used hormonal contraceptives slept 7 minutes less on average than women who do not use these contraceptives.
Hormonal contraceptives, which allow women to plan when to have children, are one of the most commonly used medications around the world. The World Health Organization estimates that 26% of women of reproductive age worldwide use some type of hormonal contraceptive.
In recent decades, the use of hormonal contraceptives has gone beyond contraception only and they are being employed as therapy for various adverse conditions such as facial acne, seborrhea, alopecia, hirsutism and premenstrual dysphoric disorder. Their use has also been associated with lower incidence of ovary, endometrial and colorectal cancer.
It is known that sleep in women changes with age and that these changes are caused by hormonal fluctuations. There is, however, not enough knowledge about how and if hormonal contraceptives, that. by their very nature, cause changes in hormonal levels, affect sleep. So far, some studies have reported positive effects of hormonal contraceptives on sleep patterns and some have reported negative effects.
“There is strong evidence showing that alterations of female sexual hormone levels influence sleep,” said study author Gabriel Natan Pires, a psychobiology researcher at the Federal University of São Paulo.
“Most of it comes from data on postmenopausal women, since the reduction on hormone level in this stage of life is associated with an increase in sleep disorders (mainly obstructive sleep apnea and insomnia), and also because hormone replacement therapy usually improves sleep in these cases. There are also studies showing that the normal hormonal oscillations observed along the menstrual cycle are associated with sleep complaints.”
“Then, driven by the previous data regarding the relationship of female sexual hormones and sleep, we questioned if contraceptive pills would also be able to impact sleep among women of reproductive age. Hormonal contraception (mainly pills) is widely used, but there are very few studies analyzing it,” explained Pires, who conducted the research along with Andréia Bezerra as part of her PhD thesis.
“Our hypothesis was that, just like with hormone replacement therapy in menopause, the use of contraceptive pills could improve sleep in women of reproductive age. We aimed to evaluate this hypothesis by means of a meta-analysis, a type of research design that combines data from several other studies into a single analysis.
To systematize the existing knowledge on the relationship between hormonal contraceptives and sleep patterns in women, the researchers analyzed data from 13 published studies on hormonal contraceptives and sleep.
Study authors filtered a total of 3,060 papers found by searching the PubMed database using keywords about hormonal contraception and sleep for studies on women of reproductive age (18-45 years of age), that involved hormonal contraceptive use or exposure, and recorded different properties of sleep. Among these, they identified 13 studies that met their criteria and extracted data on sleep and hormonal contraceptive use from them.
Pires said he was surprised to find “that all studies available on this topic (which were used for our analysis) are purely observational, and no randomized controlled trials about it have been performed so far.”
“Most of the studies were comprised convenience samples, in which there was no restriction or control over the contraceptives being used (including type, composition, dosage, use length and administration route). The few that have controlled the type of contraceptive were all related to oral combined formulations,” the researchers wrote. They also noted that studies used different methods to assess sleep quality and characteristics.
Overall, some studies reported better sleep efficiency in women who used hormonal contraceptives and some reported better sleep efficiency in those that did not. When all the sleep characteristics were compared across different studies, the researchers found that the only difference between the two groups was in the finding that women who use hormonal contraceptives wake up on average seven minutes earlier counting from sleep onset (the time when the person falls asleep) than women not using these contraceptives.
“Unlike our hypothesis, contraceptive pills did not influence the sleep of women of reproductive age in a significant way,” Pires told PsyPost. “It means that in a general perspective, taking hormonal contraceptives is not likely to influence women’s sleep, neither improving nor worsening it.”
“But this is a general conclusion, that might be valid for most but certainly not for all women taking contraceptive pills. If a woman who’s taking contraceptive pills feels the treatment has led to any sleepiness, fatigue, insomnia or any other sleep-related symptoms, she should discuss it with her gynecologist/GP. This is especially relevant for those who are are beginning their treatment or that have changed their pill recently.”
This study systematizes available scientific knowledge on the effects of hormonal contraceptives. However, a limitation that should be taken into account is the fact that the studies included in this analysis are observational, comparing different groups of women who were not matched for their individual characteristics. This means that any differences found or lack thereof could be due to differences between groups that are not related to hormonal contraceptives. Also, the study designs do not allow any cause-and-effect conclusions.
“While our conclusions seem to be valid for contraceptive pills in general, this conclusion should not be applied to any specific contraceptive formulations individually,” Pires said. “There are several contraceptive formulations currently available, and their formulations, dosage and route of administration vary considerably. It is possible that eventually one specific contraceptive formulation could improve sleep, therefore being prefered for women with insomnia; or the opposite, that a given contraceptive presentation could worsen sleep, therefore not being recommended for women with sleep complaints.”
“In any case, these more specific conclusions would only be possible to answer when proper randomized controlled trials are performed. We are now particularly interested in contraceptives with specific administration routes, such as hormonal intrauterine devices, since the way the hormones reach the body might influence their systemic effects, including sleep.”
The paper “The effects of hormonal contraceptive use on sleep in women: A systematic review and meta-analysis” was authored by Andréia Gomes Bezerra, Monica Levy Andersen, Gabriel Natan Pires, Sergio Tufik, and Helena Hachul.
