Women’s Hormones Impact Sleep

Beginning as teens, through the reproductive years, to the menopausal transition and in menopause

Many women have sleep complaints related to their menstrual cycle. It's likely that you know someone who has this problem, or have this sleep challenge yourself. Reproductive hormones shape women's sleep and sleep complaints throughout the lifespan.

The Menstrual Cycle
Over the course of the menstrual cycle, reproductive hormones vary, which is important, as these reproductive hormones influence sleep and circadian rhythms. There are two basic phases of the menstrual cycle, starting with the follicular phase. Ovulation (when the egg is released) happens in the middle, between these two phases. The second part of the menstrual cycle is the luteal phase. At the end of this phase bleeding happens.

In the first part of the menstrual cycle, in the follicular phase, estrogen rises. Right around ovulation estrogen peaks as do two hormones - luteinizing hormone and follicle-stimulating hormone. In the luteal phase, estrogen drops and progesterone is the dominant hormone. Then menses occurs and the cycle starts again.

Starting in Adolescence
Starting from adolescence, women will have sleep complaints more so than males their age. This increased prevalence continues throughout the lifespan. Often about 2 to 3 nights before, or around, the time of menstruation there will be an increase in sleep complaints. These can be either insomnia-type complaints or excessive sleepiness. Women may find they're actually sleeping more hours than they do at other times in the month. These changes are due to the influence reproductive hormones have on both sleep and on our circadian rhythm. It can also be due to cramps, pain, headache, or other premenstrual symptoms (PMS). Women with PMS are more likely to have sleep complaints, and sleep complaints worsen PMS (1). Those who use hormonal contraception have a 6% increase in sleep complaints compared to those who use non-hormonal contraception.

Pregnancy
As a woman gets into her childbearing years, if she has a pregnancy, it's likely that the pregnancy will disturb her sleep. Let's talk about what a woman can expect during each trimester.

In the first trimester, women often feel quite fatigued and they may find that they're sleeping longer at night, or want to nap during the day. This is normal as the body adjusts to pregnancy. Typically, in the second trimester, women find that their sleep is actually better, as is their energy.

Once women get into the third trimester of pregnancy, sleep is more disturbed for several different reasons. First of all, as their body changes, it may be difficult to simply be comfortable in bed. The joints may start to relax and get looser as the body prepares for delivery. It can be very helpful to have proper support from pillows. Lay on your side for sleeping, with a pillow under your upper arm so your shoulder is supported in a neutral position.  Have a pillow between your knees to keep the pelvis in neutral alignment. A pillow under the belly can also increase comfort. Long rectangular body pillows can be used. There are also slightly curved or “C” shaped pillows designed especially for pregnancy that support all these areas – place it under your head, around underneath the belly, and then between the knees.

A couple sleep disorders are more likely during the third trimester of pregnancy, primarily restless leg syndrome and obstructive sleep apnea. Restless leg syndrome is associated in some people with anemia, which is an iron deficient state. As a woman goes through pregnancy, blood volume needs to be built up. And that takes iron. So women's iron stores can get depleted by the time they're in their third trimester, which contributes to an increase in the prevalence of restless leg syndrome. Restless leg syndrome can cause difficulties falling asleep at the beginning of the night, or wake women up after that first sleep cycle. The other sleep disorder that increases in pregnancy, particularly the third trimester, is obstructive sleep apnea. In obstructive sleep apnea the airway at the back of the throat is collapsing for 10 seconds, 30 seconds, maybe as long as 45-50 seconds at a time. The diaphragm is still pumping, but no air is passing through this obstruction. The reason it happens more in late pregnancy is that many women develop edema, which is swelling of the tissues. Even the airway can become swollen, making it easier to obstruct during pregnancy.  

After pregnancy, women are at increased risk of post-partum depression if they had sleep complaints. Immediately after the birth, mothers total sleep time is an hour less than before the pregnancy. Six years later, mothers’ sleep is not fully recovered to pre-pregnancy quality or quantity (2). Even when children are older, mothers may still be vigilant during sleep to the needs of their children, leading to that sense of “sleeping with one eye open.”

Women who do shift work have greater incidence of menstrual irregularities than women who stay on a typical day schedule. We will focus on the health of shift workers in a future article.

Perimenopause
In the perimenopausal years, reproductive hormones fluctuate erratically, rather than following the predictable pattern described above. As reproductive hormones impact sleep and circadian rhythms, these fluctuations translate into more sleep complaints. This is in part due to hotflashes and nightsweats, with the severity of sleep complaints correlating somewhat with the severity of hotflashes.

Postmenopause
Postmenopausal women have the highest prevalence of sleep disorders compared to any other age group. Some sleep complaints are simply due to age-related changes that are experience by men as well. With age our slow wave sleep declines, causing the sensation of not sleeping as “deeply” as we did when younger. The circadian rhythm also shifts earlier, so women will often feel sleepy earlier in the evening, and be ready to wake earlier in the day. Sleep disorders are more prevalent, with 58% being a poor sleeper, 31% sleep apnea, 64% restless legs syndrome, 38% insomnia, and 36% daytime sleepiness (3). These are striking numbers of postmenopausal women with sleep disorders!

Sleep Skills:
Starting early in life, women’s sleep is impacted by reproductive hormones. This deserves attention and treatment to problem solve, rather than simply being resigned. Here are some steps to take:
1.    Track your menstrual cycle along with sleep to determine if there’s a correlation between symptoms in both arenas.
2.    Then get care for both sleep and for any hormonal imbalances. In my clinical experience it is necessary, and worthwhile, to address both sides of the equation.
3.    During pregnancy, note any sleep symptoms and mention them to your healthcare provider. As poor sleep during pregnancy has some negative consequences to you and your baby, treat these sleep problems as they arise. Be particularly watchful for short sleep total, restless legs syndrome, and obstructive sleep apnea.
4.    During the menopausal transition, use strategies to strengthen your sleep and circadian system so that you’re better able to withstand the effects of hotflashes and nightsweats. Do treatments with your healthcare provider to minimize menopausal symptoms.
5.    For the rest of your life, continue to take sleep problems seriously, as the prevalence is greatly increased. The good news is that these disorders are all treatable!
6. If you’d like to evaluate whether there’s correlations between your menstrual cycle, sleep and daytime experience, get the tracker by becoming a paid member.

I hope this helps you and your loved ones get the sleep you need to thrive. Come back next Thursday for a discussion of how our sleep is impacted by wildfire smoke and ways to reduce the harm.
Dr. Catherine

Resources:
- You’re Invited!  Youtube Live on how Obstructive Sleep Apnea is different in women on Saturday, Sept 9 at 8am PST
- SkilledSleeper course available: https://www.skilledsleeper.com/

Select References:
1.    Menstrual disturbances and its association with sleep disturbances: a systematic review - PMC (nih.gov)
2.    Long-term effects of pregnancy and childbirth on sleep satisfaction and duration of first-time and experienced mothers and fathers - PubMed (nih.gov)
3.    Global prevalence of sleep disorders during menopause: a meta-analysis - PMC (nih.gov)


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Use this Women’s Cycle & Sleep Tracker to see if there is a correlation between your cycle, sleep, and daytime experience. For paid subscribers only.