Hormones in Pregnancy

Published : 16/04/2024

Last updated: 14/07/2024

Last time you were so affected by rampaging hormones was during puberty, but it was all meant for you, to bloom into the beautiful lady you are, simultaneously making you ready for a mammas journey. 


However, pregnancy hormones are actually a bit different, they are meant to be good for the fetus, but mixed together in your system, they do feel like a hurricane of emotions surging through you. 


So its best to understand the hormones that are present during pregnancy for you to be able to make sense of things and don’t feel like you are going berserk!

List of all pregnancy related hormones

Did you know that certain hormones are help your uterine lining become soft and a safe place for the growth of the little one, some triggers your mammary glands to produce milk and some also help in formation of baby’s bones.


Also some are responsible for your frowned annoyance to silly things, like getting angry to not being able to find something. There are also the hormones that make you cry like a baby or laugh like a witch!


If you are looking for a comprehensive guide to pregnancy related hormones, or hormones that emerge after the baby is born, then you are at the right place to equip yourself with knowledge that enables your body to support and nurture a tiny human being.


Enlisted here are the main hormones that plays a key role during pregnancy and helps prepare for labor and delivery. [1]


  • FSH (follicle stimulating hormone)
  • LH (luteinizing hormone)
  • HCG (human chorionic gonadotropin)
  • Estrogen
  • Progesterone
  • Relaxin
  • HPL (human placental lactogen)
  • Oxytocin
  • Prolactin

Follicle Stimulating Hormone (FSH)

The follicle stimulating hormone is made by the pituitary gland in the brain and directs the ovaries to make eggs and estrogen. FSH helps control your monthly cycle.

FSH is the first of a cascade of hormones that’s necessary to launch your pregnancy and is present before you even conceive. FSH stimulates eggs to grow in the ovaries, which increases the production of estrogen. Rising estrogen levels signal the body to produce a surge of LH, leading to ovulation and potentially pregnancy.

Cool fact: women who have fraternal twins tend to have higher levels of FSH, including women over 35, which is why this group is more likely to have double buns in the oven [2]

Luteinizing Hormone (LH)

A hormone that’s made by the pituitary gland and works in concert with FSH to orchestrate your menstrual cycle. Luteinizing hormone levels rise just before ovulation and LH triggers the release of an egg from your ovary.


While FSH prompts the production of estrogen, estrogen calls on LH to burst the follicle and free up an egg. The post ovulatory follicle creates the corpus luteum that disintegrates in about 14 days if you are not pregnant, at which point your hormone levels will drop and your period will arrive. [3]

If a sperm and egg come together, the corpus luteum lives on, producing the right hormones, including progesterone, to ripen the uterus and nourish your growing baby.

If you’re struggling to conceive, your doctor may check your LH levels. When these are higher than normal, ovulation may be impacted or your hormones may be imbalanced on the whole, which is sometimes behind a case of polycystic ovarian syndrome (PCOS). [4]

Human Chorionic Gonadotropin (HCG)

Human chorionic gonadotropin is a hormone that gets to shine, as it’s normally produced just during pregnancy. [5]


This hormone amps up the production of estrogen and progesterone, though you and hCG may have already met if you’ve taken a home pregnancy test. Yup, it’s this chemical that coaxes a sweet happy face to appear on the pee stick.


Early on in pregnancy, hCG levels are low, but they soon rise and double every two days, peaking between weeks 7 and 12 and then falling back at the start of your second trimester. Next, the placenta starts making estrogen and progesterone, though hCG is still with you. In fact, this hormone affects the immune system, sometimes leaving you more vulnerable to colds and the flu.


Estrogen is the main female hormone that contributes to sexual development, including the growth of breasts, and it kickstarts and regulates a woman’s menstrual cycle. It also helps to keep your bones healthy and cholesterol levels under control. [6]


Along with progesterone, estrogen is one of the two main hormones that get the pregnancy party started. Produced by the ovaries and later by the placenta, estrogen helps the uterus grow, maintains uterine lining, regulates other key hormones and triggers the development of baby’s organs. And when it’s time to breastfeed, estrogen promotes the growth of breast tissue and helps milk flow.


Got a stuffy nose — or blotchy skin? Estrogen is also behind swollen mucous membranes and it causes extra blood flow to your skin, which can result in a red, itchy complexion. And estrogen joins other hormones to cause hyperpigmentation like darker nipples and melasma, brown patches on nose, cheeks and forehead. [7]


Progesterone, which is made mostly in the ovaries after each monthly ovulation and helps regulate your menstrual cycle, is the second half, along with estrogen, of the “big two” sex hormones.


This all-important hormone kicks into gear shortly after ovulation by helping the uterine lining to become receptive to implantation of a fertilized egg. Progesterone, along with the hormone relaxin, can cause some GI woes, such as heartburn, indigestion, constipation, and bloating.


Progesterone teams up with relaxin again to help soften ligaments and cartilage, and loosen your joints to prepare you for labor. And if your gums swell and start to bleed, your skin breaks out or you feel super sweaty, that’s the handiwork of this chemical, too. [8]


This hormone plays a big role in a woman’s reproductive process. Relaxin levels rise after ovulation and then helps prep the uterine wall to get it ready for pregnancy. Relaxin levels drop back down until the next cycle if there’s no fertilization that month.


If you do end up conceiving, relaxin is at the ready and lives up to its name, since it helps to relax your muscles, bones, ligaments and joints in the pelvis later in pregnancy in preparation for labor.


Relaxin also softens and lengthens the cervix. Its limbering mechanism may make you feel off balance and wobbly as you walk (be careful!). [9]

Human placental lactogen (HPL)

Human placental lactogen is also sometimes called human chorionic somatomammotropin, but the “lact” part tells you all you need to know — it’s connected to milk production.


This hormone is produced by the placenta to adjust your body’s metabolism to feed your baby. Along with placental growth factor, it preps your breasts to breastfeed. This hormone helps make colostrum, which is the antibody-rich pre-milk that precedes actual breastmilk. In some women, hPL and placental growth factor are thought to lead to insulin resistance, resulting in gestational diabetes.


Oxytocin is made by the hypothalamus and then secreted by the all-important pituitary gland. This pregnancy hormone is a critical one when it comes to labor and delivery.


Though oxytocin is around throughout your pregnancy, this muscle-contracting hormone is mostly known for stimulating labor contractions. And if your labor is slow to progress, you might get a shot of Pitocin, the synthetic version of oxytocin, to help move things along. Once you’ve delivered, oxytocin helps to shrink the uterus down in size and move milk into the breasts.[10]


Prolactin is another hormone that’s made by the pituitary gland, and if you squint you can see “lact” in this hormone, as in lactating, lactation — and milk! [11]


This milk hormone’s main job is to help enlarge your breasts and produce the milk you’ll need to feed your baby after delivery. Prolactin also charges up the adrenal glands that trigger new hair growth in unexpected places (such as on the belly and face), but this fuzz usually disappears around six months postpartum.

Other Pregnancy Hormones

Did you think that was the end of the list? In fact, there are a few other significant hormones at work during pregnancy, including the following:


Erythropoietin: Regulates red blood cell production.


Calcitonin: Promotes bone formation.


Vasopressin: High levels of this hormone lead to water retention.


Thyroxine: A thyroid hormone that increases an expectant mom’s oxygen 

consumption, interacts with growth hormones to regulate and stimulate fetal growth, and is used in the development of the baby’s central nervous system.


Insulin: Controls the metabolism of foods by both mother and baby.


Adrenocorticotropic hormone: A chemical that causes adrenal glands to pump out hormones that contribute to stretch marks and swelling.


Cortisol: An adrenal hormone that aids in fetal lung maturation. In high concentrations, cortisol, which is the body’s stress hormone, can interfere with progesterone levels. Cortisol may also adversely affect the hippocampus, which plays a critical role in learning and memory and may explain pregnancy forgetfulness and brain fog.


Endorphins: The brain’s natural happy hormones can help you endure labor pain — and perhaps forget it altogether once you meet your sweet new baby.

A Gentle Nudge from Mammas Journey

Once the baby arrives you might think that these hormones are filtered out from your system. But the truth is that these things are flowing through your system even after delivery. 


Some hormones will drop for example Estrogen and progesterone others like Oxytocin and prolactin will rise. The cocktail of these hormones are like storms raging in your system and can be tough for new mothers – leading to postpartum.


This is common for 80 percent of new mothers, therefore if you are feeling sad or out of sorts, do talk with your doctor [12]. 

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