Pregnancy is one of the most hormonally charged events you can go through. One minute you’re sobbing over a tragically soggy bottom on Bake Off, the next, you’re hunting around for Marmite to spread on your post-dinner Twirl. If you don’t feel quite yourself, that’ll be because your body’s producing more oestrogen during those nine months than you would normally over an entire lifetime. And then, before you know it, the baby’s here and… you still feel up in the air. You’ve gone from mood swings to not remembering where you put your house keys or what your next door neighbour of five years is called. Maybe you feel foggy years after giving birth.

While some of us might already be familiar with the hormonal rollercoaster of pregnancy, we rarely hear about how our bodies change after having a baby. It’s often the kind of thing you only discover when it happens to you. So, to find out why you might still be feeling like your brain is struggling to engage months after having a baby, we’ve been talking to Dr Ghazala Aziz-Scott, clinical director and specialist in women’s integrative health at the Marion Gluck Clinic. This is your comprehensive, expert-led guide to everything that happens to your hormones, from conception to breastfeeding.  

Congratulations! You’ve peed on a stick and it’s tested positive for something called human chorionic gonadotropic hormone – a chemical which marks the start of this hormonal rollercoaster. When you’re trying to conceive, Dr Aziz-Scott says that “good levels of progesterone” during the luteal phase are essential for thickening up the womb lining. When an egg is fertilized, that thicker lining will help the embryo to implant, and the corpus luteum (a temporary collection of cells that stays in your ovaries after you’ve ovulated) will carry on producing progesterone. 

Over the next few weeks, the placenta and foetus will start producing progesterone as well.

Other hormones being produced during pregnancy include human placental lactogen, prolactin and oxytocin. 

The two biggest hormonal players in this whole process are oestrogen and progesterone. Oestrogen from the placenta helps to maintain the pregnancy and helps the foetus to develop. Progesterone keeps the womb lining thick so the foetus can remain implanted and suppresses contractions – an important factor in avoiding pre-term labour. Both hormones are important for immune regulation.

Keep catching colds? Wondering why you can’t get on the Tube without getting another bug? You’re more susceptible to bugs and colds when pregnant, and that happens for good reason. “Your immune system needs to be a bit down-regulated because you don’t want your body to reject the pregnancy as a foreign object,” Dr Aziz-Scott explains. Even when you aren’t pregnant, when progesterone rises ahead of your period, you might find your immune system struggles more than usual (ie period flu). 

OK, you’ve made it to the really hard bit. Childbirth is painful but your body is psyching itself up to handle it, thanks to its production of oxytocin. Known as the ‘love hormone’, production of this chemical ramps up as the pregnancy progresses – and it’s important for a variety of things. “It helps with contractions in labour and milk production, and it also strengthens the bond between mother and baby,” says Dr Aziz-Scott. “It increases during pregnancy and spikes at delivery”. 

You’ve done it! You’re lying there, holding this bundle that you’ve grown and feeling overwhelmed at the fact that you’ve birthed the most magical human to ever exist. That’ll be the oxytocin talking. Take all the photos but maybe wait before you start contacting modelling agencies just yet.

Oxytocin is involved in milk production, while prolactin signals breast tissue to grow and helps with milk. Its levels spike after delivery when breastfeeding needs to kick in. For the next few days, you’ll be flooded with feel-good oxytocin, which will override any other hormonal fluctuations – even though your oestrogen and progesterone-producing placenta has now gone. 

If you’re wondering what to do with that placenta, the wellness industry quickly adopted the idea of drying and encapsulating the organ for various supposed health benefits. As the main hormone producer during pregnancy, it’d follow that consuming your placenta might help slow the rapid decline in oestrogen and progesterone post-labour, right? Dr Aziz-Scott is quick to give that notion a definite “no”. “The hormones will just get digested, so no, I don’t think you’d get a boost – although placentas are probably very high in iron and other nutrients. It’s like a self-made black pudding.” 

Ahh, halcyon days. You’ve caught your breath, the baby is tiny and adorable and people have started dropping cooked meals at your door. Now’s the time to get this baby to latch on and get feeding – and if you do manage it, you’ll have prolactin to thank. 

It’s been on the rise for some time but levels increase significantly after giving birth. The more you attempt to breastfeed, the more prolactin will be produced. It’s a pro-lactation hormone that helps to stimulate the breast tissue and produce milk – and it’s linked to oxytocin. That love hormone gets released in response to breastfeeding, bonding you to your baby. It’s also really useful for reducing postpartum bleeding as it can help the uterus to contract.

You come crashing down back to earth about a week after the birth. That’s when oxytocin starts to reduce, along with the rest of your pregnancy hormones. Dropped oestrogen is responsible for hair shedding, while decreasing progesterone can have a huge mental knock. Women, Dr Aziz-Scott says, tend to be quite happy in pregnancy because progesterone stimulates our GABA receptors (GABA being the main inhibitory neutrotransmitter in the brain). “When you’ve got good levels of progesterone, your GABA receptors are really happy – you feel calm and relaxed. But when you then get a rapid drop of oestrogen and progesterone, you’re likely to experience the ‘baby blues’ or postnatal depression (PND).”

Of course, PND is a complicated illness that goes beyond hormonal imbalance. “Other factors contribute to a women’s mood,” Dr Aziz-Scott highlights. “[You’ve got to ask] is the baby healthy? Did she have a really terrible delivery? Is there much family support? Is the husband being supported? What’s their socio-economic status? Women who’ve had mental health issues before they gave birth are more at risk, as are those who have financial difficulties or other medical conditions.” She also suggests that we tend to “recycle our own emotional world” when we have babies, so any repressed trauma or discomfort from our childhoods can come back up.  

Some women breastfeed for a couple of months, others a couple of years. You’ve decided to carry on for a while and that means your menstrual cycle – and your regular ebb and flow of hormones – has been arrested. That’s because prolactin again stops ovulation, so women who breastfeed don’t ovulate. And if you’re not ovulating, you’re not going to get pregnant. “It’s probably an evolutionary thing,” says Dr Aziz-Scott. “There are some women who still get pregnant while breastfeeding, but for the majority of women, your body doesn’t want to get pregnant while breastfeeding another child. So usually, you won’t have periods.”

The moment you start weaning your baby, however, the amount of breastmilk you produce starts to go down and you might start to get breakthrough ovulation. If you choose not to breastfeed for whatever reason, your prolactin levels will return to normal in three-to-six weeks after giving birth. 

Motherhood obviously changes you, but are any of those changes hormonal in the long term? Can having umpteen pregnancies change you hormonally? Dr Aziz-Scott says that it’s not pregnancy that changes us but the age at which we go through it. “You’ve got to remember that as you’re having multiple pregnancies, you’re progressing through your natural hormonal changes. Women are having kids a lot later in life these days, with the average age of [first] pregnancy being around 31 in the UK. If we have kids in our late 30s and early 40s, our bodies might also be going through perimenopause – and if you’ve already got kids and are pregnant, you’re also dealing with the stress of already having dependents, so your stress levels are going to have an impact on your sex hormones and menstrual cycle.”

In other words, once pregnancy is done, you hop off one hormonal rollercoaster and line up for the next ride. 

Images: Getty