Hormones in Daily Life & Pregnancy
I’ll never forget the exhaustion I felt during certain times of the month, so tired I’d sleep for 10+ hours. I would also experience ravenous hunger, eating an entire jar of Nutella (yes, the entire thing) in one sitting. And okay, I’ll admit I have been guilty to the not so occasional spouts of agitation and irritability. My mom, the most patient woman in the world, always reasoned these behaviors back to hormones. As a teen I’d roll my eyes and express frustration towards my lack of self control. As an adult I’d like to think that body literacy and maturity has curbed some of these tendencies. Nevertheless, the more I learn about these mysterious messengers in our bodies, the more I realize that maybe my mom has always been on to something.
Hormones are chemical messengers that are produced in endocrine glands throughout the body, which are secreted directly into the bloodstream, and then carried to organs and tissues to exert their functions. When something is transmitted through the blood supply, it means that it is widely spread. It has access to go everywhere. And there are many hormones that function throughout the body.
When it comes to the cis-female body, hormones ebb and flow on a 28-day cycle. Estrogen, Progesterone, and Testosterone play roles in the regular changes of a woman’s cycle. However, there are plenty of others that I won’t get quite into.
Average Menstrual Cycle
Estrogen
Estrogen plays a crucial role in menstruation, sexual functioning, vaginal lubrication, elasticity to vaginal tissues, and bone health. It is responsible for the growing of the uterine lining (the lining that is shed during menses) and also maturing the egg prior to ovulation. Estrogen is most abundant in the first half of the menstrual cycle.
As women, our bodies go through significant transformations throughout the lifespan. During pregnancy, estrogen production is high. Immediately after childbirth estrogen levels drastically drop. If breastfeeding, this is good! It allows the production of another hormone, prolactin to be released, which maintains milk production. If you continue to breastfeed, your prolactin levels will continue to be elevated and estrogen levels will continue to be lower. No ovulation means low estrogen. This estrogen drop that occurs after childbirth and during breastfeeding mimics the hormone changes brought on by menopause.
If estrogen production allows for vaginal lubrication and elasticity of vaginal tissues, low estrogen levels can cause:
vaginal dryness
low libido
So learning how to care for yourself—how to care for your skin and tissue around the vulva when its fragile — you are getting ahead of the curve and learning how to care for yourself in the present and in the future. Your skin will be grateful for a moisturizer such as Vitamin E and clean water or silicon-based lubricant during sex (see Lube Guide for details).
Here’s why this matters: if the skin is dry, your muscles are prone to clench. If your muscles are tight, penetration can be uncomfortable. If you’re in discomfort during sex, it’s difficult find a sense of relaxation that allows for orgasms. Happy pelvis=happy human!
Testosterone
Testosterone is typically discussed in relation to men, but plays an important role in women as well! Testosterone helps women maintain muscle mass and bone strength. It is also responsible for the body’s sexual arousal response, enhances libido, and helps with a sense of overall wellbeing. In the average cycle, it surges during ovulation and just before menses. Have you ever noticed you’re more interested in sex around these times? You have that extra boost of testosterone to thank!
Another thing to note is that a common medication millions of women take daily reduces testosterone levels: oral contraceptives (or the pill). This is the reason why it’s so effective at improving acne. In addition, testosterone production drops almost in half during menopause.
Progesterone
Progesterone doesn’t get a ton of press, but it contributes to maintaining pregnancy, preparing the body for conception, and regulating the monthly cycle. It peaks in the second half of your cycle. If there’s no bun in the oven, estrogen and progesterone levels drop and menstruation occurs. If pregnant, progesterone levels remain elevated throughout pregnancy. The combo of high estrogen and progesterone levels suppress ovulation.
The increased progesterone levels to suppress ovulation is the thought process behind artificial progesterone (or progestin) in birth control pills.
Higher levels of progesterone are linked to PMS symptoms —mood swings, breast tenderness, feeling bloated.
Relaxin
Relaxin is a bit of a mystery hormone. I’ve included it because I find it incredibly interesting. Despite years of research, there is limited understanding of relaxin’s broad role in a woman’s menstrual cycle and during pregnancy. It plays a role in uterine growth and circulation. Relaxin concentration peaks 6-7 days after ovulation, with a low or non-detectable level during other times of the cycle. It’s at its highest levels during the first trimester of pregnancy.
It is more known that relaxin relaxes the wall of the uterus and prepares the uterus lining for pregnancy. Relaxin softens and widens the cervix and relaxes the ligaments of the pelvis, thus facilitating delivery for childbirth.
What’s not quite as established is how broad this role has in the female lifespan. There is some evidence that supports the role in relaxin as a requirement in a healthy pregnancy. Diminished relaxin is linked with increased risk of miscarriage and preeclampsia.
On a musculoskeletal level, relaxin promotes wound healing and bone remodeling. Some studies reported higher relaxin levels in pregnant women with pelvic girdle instability and lower back pain. The role of relaxin production appears to go even outside of the pelvis. Estrogen and relaxin receptors have been found in the human female anterior cruciate ligament (ACL). Some studies link an association between ACL injuries and stages of menstrual cycle—that there’s a higher occurrence of ACL injuries during the ovulatory phase (during ovulation) versus the luteal phase (after ovulation). The jury’s still out on these correlations, but it certainly raises the eyebrow of a pelvic floor therapist who has experienced knee pain during certain times of the month.
Conclusion
Hormones really can impact a woman’s functioning. By understanding your hormones and your cycle, you can better understand your body’s needs.
*insert my mom’s infamous "I told you so" facial expression here*Resources:
Marshall, S. A., Senadheera, S. N., Parry, L. J., & Girling, J. E. (2016). The Role of Relaxin in Normal and Abnormal Uterine Function During the Menstrual Cycle and Early Pregnancy. Reproductive Sciences, 24(3), 342–354.
Dehghan, F., Haerian, B. S., Muniandy, S., Yusof, A., Dragoo, J. L., & Salleh, N. (2014). The effect of relaxin on the musculoskeletal system. Scandinavian journal of medicine & science in sports, 24(4), e220–e229. https://doi.org/10.1111/sms.12149