Understanding your hormones during pregnancy

Understanding what is happening to your body during pregnancy will help you cope

Louise Pyne on understanding the emotional and physical ups and downs of your pregnancy

Pregnancy is one heck of a rollercoaster ride. The fluctuating hormone levels that kick in from conception until after you give birth bring with them a whole range of physical and emotional symptoms – good and bad! Here, we discover exactly what’s going on inside your body and how to feel your best while you wait with anticipation for your little arrival.

The first trimester

Rising levels of human chorionic gonadotropin (hCG) are responsible for those all-important lines that show up on your pregnancy test, confirming that you’re expecting. Produced by cells in the placenta, hCG helps the embryo to grow properly and levels of this hormone rise steadily in the first trimester, often resulting in classic morning sickness symptoms. “Initially, the effects of a rising hCG level can make you feel nauseous, and you may even vomit,” says Dr Penelope Law, consultant obstetrician and gynaecologist at The Portland Hospital (theportlandhospital.com). It’s not all doom and gloom, however, as levels drop from weeks 10-12, helping any sickness symptoms
to subside.

Along with a rise in hCG, levels of oestrogen and progesterone also increase in order to sustain a healthy placenta and foetus. “The rising oestrogen and progesterone levels may cause breast tenderness and growth, and you may feel more emotional at this time. The good news is this passes soon,” continues Dr Law. On the plus side, rising progesterone can also result in increased hair follicle production, meaning your locks will never have looked so thick and glossy!

You may also feel more tired than usual thanks to the extra cellular activity involved in creating a baby. To alleviate fatigue, make sure you eat little and often, and keep healthy snacks such as raw nuts and oatcakes in your handbag at all times.

The second trimester

You’re probably getting into the swing of pregnancy by the second trimester and becoming comfortable with your ever-changing body shape. By now, your morning sickness should have passed and your energy levels should start to soar once again. “Your body is beginning to adjust to the new levels of hormones and you’re beginning to feel physically better, so now is the time to get your maternity clothes and look up pregnancy yoga and Pilates classes,” says Dr Law.

The risk of miscarriage also falls from week 14. “This can ease anxiety, and this trimester is noted for women feeling that ‘bloom’ both physically and mentally,’ explains GP Dr Gill Jenkins. You still need to keep your diet healthy, with a good supply of fruit and veg for micronutrients and fibre, and stay active.

The third trimester

With only a few months to go, by now you’re probably experiencing a cocktail of different emotions, from pre-labour nerves to sheer excitement. All this, coupled with the physical strain of carrying a growing baby, and the third trimester can be hard work. “As your baby grows you may become less mobile, more tired and symptoms such as indigestion, back ache and difficulty sleeping are common,” says Dr Jenkins. Oestrogen and progesterone levels are high at this time, as is prolactin, a hormone which prepares the breast tissue for milk production.

Talking to your midwife will help, and have a plan for labour. “It’s important to be open-minded about your birth plan. While a water birth or home birth may be ideals, you must consider the possibility of needing more support, from simple pain relief to more complex interventions such as episiotomy or a caesarean, or a longer stay in hospital,” continues Dr Jenkins. In the last few weeks you will need more rest and support from your partner, friends or family. Even simple things such as having someone cook for you,
or give you a massage, will help.

In the run up to labour, your body is preparing for your baby’s arrival by producing oxytocin which stimulates the labour process and human bonding. Once you go into full-blown labour your ‘flight or fight’ hormones kick in. “You will be producing increasing levels of adrenaline and noradrenaline which aid you through a long labour and the first few days following delivery,” explains Dr Law.


Following delivery, hormone levels change again. “Your body will produce prolactin, which ensures that the appropriate human milk composition is produced – your body knows if your baby is born early and magically adjusts the components of your breast milk to suit the size of your baby,” continues Dr Law.

Levels of oestrogen and progesterone also rapidly fall at this time. “Emotional turmoil, causing the ‘baby blues’ can in part result from the hormone changes as well as the reality of the hard work of the post-partum period. However, for some women crashing hormone levels may trigger postnatal depression which lasts beyond the first few days and needs medical help,” explains Dr Jenkins.

Don’t fret however, as for the majority of women feeling blue, it’s simply a matter of getting rest, plenty of fluids – especially if you are breastfeeding, adequate pain relief (your midwife will advise what is safe), and taking any offer of help. “Keep your expectations of yourself and family low – let them prepare meals, and don’t feel you have to do what you previously did in regards to housework. Just enjoy your baby, or enjoy some rest while the rest of the family look after the baby for part of the day,” recommends Dr Jenkins.