YOUR PREGNANCY HORMONES

What are the main pregnancy hormones?

Hormones are chemical substances secreted by special glands into your bloodstream to ensure that your body’s organs work properly. During pregnancy, changes in the levels of some hormones help your body to prepare for the growth of your baby, birth and breastfeeding. These changes can, however, make you feel unusually emotional, nauseous and tired.

Types of pregnancy hormones and their side effects

Human chorionic gonadotropin (hCG)

One of the first hormones to be produced by the fertilised embryo, and later by the placenta. hCG can be detected around 10 days after ovulation, and often after 5–6 days. The level of hCG doubles every 2-3 days until it reaches its maximum level after between 8-11 weeks. The job of hCG is to stimulate your body to produce the other hormones you need for a healthy pregnancy. It is not produced naturally by the body except during pregnancy, and it can be detected in urine, so it is the hormone used by pregnancy tests to determine whether or not you are pregnant.

Progesterone

Progesterone is a major hormone of pregnancy and high levels are needed throughout each trimester. It is first produced by the ovaries and helps build the lining of the womb to accept and nourish the fertilised egg. After about 10 weeks the placenta takes over the production of progesterone which continues to support the pregnancy. Progesterone reduces the risk of the uterus contracting before labour and it prevents the production of milk until after the baby is born. It also suppresses the mother’s immune system so that her body does not react to the presence of the developing baby.

Oestrogen

Oestrogen is first produced by the ovaries until the placenta and developing baby take over. This pregnancy hormone plays a key role in the healthy growth and metabolism of the developing baby including the development of the baby’s lungs, kidneys and liver. It regulates other pregnancy hormones, maintains the function of the placenta and prepares the breasts (along with progesterone) for the mighty job of milk production. It also enables the muscles of the womb to respond to another hormone (oxytocin) which triggers labour.

There are many other hormones involved in pregnancy, such as:

Relaxin

Relaxin, as the name suggests relaxes muscles, ligaments and even the walls of the arteries in pregnancy. It allows the arteries to carry a larger volume of blood without increasing your blood pressure. It can even relax the ligaments of the pelvis to ease delivery of the baby

Oxytocin

Oxytocin has a vital role in labour and after you give birth. Oxytocin causes the womb muscles to contract regularly during labour and after birth continues to contract the womb to reduce blood loss and help expel the placenta. The hormone also supports bonding between Mum and baby and sometimes gets the nickname of the “love hormone".

Prolactin

Prolactin is vital to milk production and breast feeding your baby. When your baby suckles the brain produces prolactin which stimulates milk production

Prostaglandins

Prostaglandins are the hormone responsible for getting your cervix ready for labour. As you head towards the end of your pregnancy, your body produces prostaglandins which encourage your cervix to start slowly softening and opening.

How pregnancy hormones affect your body

The fast rise in hCG levels leads to many of the typical symptoms of early pregnancy, such as headache, fatigue, insomnia, and fluid retention.

Pregnancy hormone levels

High levels of oestrogen can cause headaches, a stuffy nose (similar to having a cold) and sensitive skin. It can also cause some areas of skin to become darker. This usually happens around the nipples and on the abdomen, but can also occur on the face.

High progesterone levels may cause stomach problems such as indigestion, heartburn, constipation and bloating. Progesterone can also cause aches and pains in the hips, make the gums more likely to bleed, and cause an increased sweat production, greasy hair and a flare up of acne

These symptoms of hormone changes are a normal part of pregnancy and are usually nothing to worry about. If you have any symptoms that you are worried about, however, you should talk to your midwife or GP.

Emotional effects of hormone changes during pregnancy

The changes in oestrogen and progesterone levels during pregnancy can have effects on the mother’s emotional state, leading to heightened emotions and mood swings. Other pregnancy hormones can also effect mood and emotion. For example, hCG and oxytocin can cause irritability and restlessness.

Emotional changes are very common and are a normal part of pregnancy for most women. If, feeling very emotional,  down or anxious is affecting your everyday life, you should mention it to your midwife who will be able to provide help in dealing with worrying thoughts and feelings.

You can also do things to help yourself cope with changing emotions during pregnancy, such as making time for yourself to relax, eating healthily, and trying to get as much sleep as possible. It may also help to talk to friends and family about how you are feeling, or to meet other pregnant women for support.