Pregnancy hormones prepare your body for birth and help grow your baby.

What exactly is a hormone? It's a chemical transmission from your endocrine system's five glands to the rest of your body. They regulate your appetite, sleep, and sex drive even if you aren't pregnant. In short, everything. When you become pregnant, your pregnancy hormones transform your body into a baby-making machine with a few unexpected side effects.

What are the Main Pregnancy Hormones?

Human Chorionic Gonadotropin (HcG)

HcG is the hormone that alerts the rest of your body to the fact that you're expecting. It's also the sign used by non-prescription pregnancy tests.

What does HcG do?
Because higher levels of HcG are linked to more extreme vomiting and nausea, it's the most likely pregnancy hormone to blame for morning sickness. Another important role is to increase oestrogen and progesterone production so that they can contribute to the baby's growth.

When will HcG matter?
Your HcG levels will climb rapidly during the first two months of your pregnancy, doubling every other day, before plateauing throughout the remainder of your pregnancy.

Progesterone

Progesterone, like oestrogen, is used in birth control pills to fool your body into believing you're pregnant so you don't get pregnant in the first place.

What does progesterone do?
This hormone is extremely important during pregnancy.

This pregnancy hormone makes your breasts more sensitive throughout the first trimester and helps them prepare to start producing milk.

It relaxes the uterus, preventing it from rejecting the foetus.

It causes bloating and exhaustion.

When will progesterone matter?
During the first trimester, progesterone levels increase before levelling down. Progesterone is produced by the placenta throughout pregnancy, thus when the baby is born and the placenta is removed, progesterone levels drop, resulting in mood swings.

Estrogen

This pregnancy hormone is closely associated with females. It helped you get through puberty while also regulating your monthly cycle.

What does estrogen do?
Estrogen promotes uterine growth and foetal development during pregnancy. It also boosts blood flow, which improves your sense of smell and gives you the "glow" of pregnancy. Spider veins and an increase in appetite are two of the side effects.

When will estrogen matter?
Estrogen levels climb throughout the pregnancy, peaking in the third trimester. Because the placenta also produces oestrogen throughout pregnancy, oestrogen levels plummet after delivery.

Relaxin

The name is self-explanatory.

What does relaxin do?
Relaxin helps your placenta grow by keeping your uterus relaxed during the first trimester. It also helps to relax your ligaments. Because you're more unstable, you're more likely to fall, but it also expands your hips and helps break your water, making labour easier.

When will relaxin matter?
As your body prepares for pregnancy, relaxin levels are at their maximum throughout the first trimester.

Oxytocin

This isn't the same as Oxycontin. That is an opioid pain reliever. Nature's version is this.

What does oxytocin do?
Our favourite hormone is oxytocin (pronounced oxy-toh-son). During sex, delivery, and breastfeeding, this so-called love hormone fills your brain, giving you warmth and fuzzies.

When will oxytocin matter?
This hormone triggers contractions, keeps them continuing during labour, and causes your uterus to contract after the baby is born. Then, while you nurse, your brain generates more of it to aid in your bonding with your baby. For the win, human bodies!

Prolactin

What does prolactin do?
Prolactin aids in the production of milk, as its name suggests.

When will prolactin matter?
Prolactin levels rise 10 to 20 times during pregnancy to prepare your mammary glands for milk production. If you start breastfeeding, the levels will remain high. When you're sleeping and in the early morning, your prolactin levels are at their maximum (which may be why many women experience their highest levels of milk production around that time).