Pregnancy Hormones

If you are pregnant then I am sure you must be sick by now of all these acne, blemishes, bloating, food cravings and emotional outburst due to the surge of pregnancy hormones. And not to forget morning sickness and heartburn adds to the list of pregnancy sufferings.

Right now, your body is high on hormones but do you know what all hormones are playing the significant role and which one is doing what?

Knowledge about what goes on inside a pregnant woman’s body will help you which is why we have compiled a list of all the hormones involved in pregnancy.

Human Chorionic Gonadotropin (HCG)

  • Placenta produces this pregnancy hormone after implantation of the baby in your womb.
  • hCG’s primary job is to tell the woman’s body to make a nest for the developing baby and not kill it.
  • It protects the fetus by repelling the immune cells of the woman’s body. It also instructs the ovaries to hold on the process of producing mature ovum from the ovarian follicles every month.
  • The level of hCG increases eight days after ovulation. hCG level peaks on the 60th and 90th day of pregnancy.
  • In the first ten weeks of pregnancy, Human Chorionic Gonadotropin level doubles in every two days.
  • hCG comes in a pregnant woman’s urine. Pregnancy tests detect this hormone to detect pregnancy.
  • Women with higher levels of hCG experience more nausea and vomiting.
Pregnancy Hormones
Pregnancy Hormones


  • Corpus lutem is the baby cell’s shed coat. It produces one of the most critical pregnancy hormones – Progesterone.
  • Corpus luteum produces progesterone till ten weeks after which placenta starts producing this hormone.
  • Progesterone is also called ‘hormone of pregnancy’ because of the major role it plays.
  • It converts the lining of the uterus to its secretory stage so that it can prepare the uterus for implantation.
  • It also makes the cervical mucus thick rendering it unfavorable for the other sperms if you have sex after conceiving.
  • During pregnancy, it starts producing and storing milk and so the credit for lactation also goes to the hormone progesterone.
  • When the progesterone level falls, you start getting closer to labor.
  • Progesterone also results in lower blood pressure. Dizziness and gastrointestinal symptoms of pregnancy are because of progesterone. Other pregnancy symptoms like vomiting, nausea, gas, and flatulence are also due to progesterone. Pregnancy hormone progesterone also causes burping, constipation, and heartburn.
  • It also stimulates the growth of hair follicles on your breast and tummy.


  • Corpus luteum initially produces estrogen. Later the placenta takes over the task of producing estrogen during pregnancy.
  • By the end of the first trimester, your body will have higher levels of estrogen in circulation.
  • It works along with progesterone and thickens and maintains the lining of the uterus for implantation.
  • Estrogen being the great companion works with growth hormone (GH) and mediates breast maturation in pregnancy. It also induces the secretion of the hormone prolactin.
  • Estrogen triggers the development of the fetus and the development of hormones in the adrenal gland of the fetus. It also stimulates the growth of the fetus’s adrenal gland.
  • The reason for ‘pregnancy glow’ experienced by some women is estrogen and progesterone.
  • Estrogen is responsible for the food cravings and increased appetite. It causes skin pigmentation and spider veins.


  • Oxytocin is known as the birth hormone. Its levels increase during pregnancy for increased nutritional uptake by the baby. It also reduces stress and makes you feel sleepy. It’s the energy conservation hormone.
  • Oxytocin is also responsible for rhythmic uterine contractions. Baby’s movements during labor send a signal to the brain. After this oxytocin levels pick up. Another term for it is the birth hormone.
  • Oxytocin is responsible for the milk ejection reflex or the letdown reflex. 
  • Oxytocin is also responsible for creating a feeling of closeness and warmth between the mother and baby.


  • Prolactin is a part of the cocktail of hormones in pregnancy. Its level increases because of high circulating levels of estrogen and progesterone.
  • Its primary function is to produce milk.
  • It also plays a role in fertility. Prolactin inhibits the production of Follicle Stimulating Hormone (FSH) and Gonadotropin Releasing Hormone (GnRH). It naturally provides spacing between kids.
  • Prolactin is present in copious amounts during pregnancy and is responsible for enlarged breasts.


  • It is another hormone synthesized in pregnant women and also in non-pregnant women.
  • Relaxin peaks within first fourteen weeks of pregnancy and also at delivery.
  • It relaxes the uterine muscles and the ligaments that hold the pelvic bones together.
  • The level of this hormone increases to ten fold in pregnancy.
  • The downside to this hormone is that you might feel your ligaments are loose. It will include your shoulders, ankles, knees, and hips. It will result in pain, inflammation, and clumsiness.

Placental Growth Factor

It is the hormone responsible for the formation of blood vessels. If placental growth factor is not produced in sufficient quantities, then you might experience preeclampsia.

It is the condition of hypertension in late weeks of pregnancy. The blood vessels in the placenta become narrow due to deficiency of placental growth factor.

Human Placental Lactogen

It is the third hormone responsible for preparing your body for lactation. The first milk after baby delivery is colostrum. Human placental lactogen is responsible for colostrum secretion. Colostrum is rich in antibodies of type Ig A. They are essential for baby’s immunity.

Human placental lactogen also shifts the metabolism of mother to utilize her fats. It allows more sugar to be available in her bloodstream. The developing baby can only take this directly available nutrient.

A high level of Human placental lactogen can increase the blood glucose and cause gestational diabetes.

FSH (Follicle Stimulating Hormone)

It is one of the early pregnancy hormones. It is responsible for follicle maturation and release. Follicle stimulating hormone is responsible for ovulation. FSH regulates most other early pregnancy or pre-pregnancy events.

LH (Luteinizing Hormone)

Luteinizing hormone is another pre-pregnancy hormone. It is an early pregnancy hormone that has a crucial role in regulating ovulation. LH surge on the 14th day of menstrual cycle causes ovulation.

Ovulation is the release of the egg from ovaries. LH hormone release is the time when the woman is most fertile. During this phase chances of getting pregnant are highest.


  1. Thank you so much for this helpful info. I am 9 weeks pregnant and experienced a small bleed. My doctor ordered a series of blood tests to measure my HCG levels. What is an HCG level and what number should my level be?

  2. Thank you vey informative easy to understand in simple terms. I’m currently a midwifery student from the Fiji Islands in the Southern Pacific.


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