Pregnancy can turn any seemingly sane woman into an unpredictable and volatile creature – and for good reason. The culprit? Hormones. Blamed for every bloat and blemish, this turbo cocktail of chemicals has earned itself a pretty bad rep during pregnancy. It’s not all bad news though. You’ll be glad to hear pregnancy hormones are responsible for some pretty incredible feats too. (Ahem, brace yourself for the inundation of compliments you’ll receive about your luscious locks and gorgeous glow!) Considering they take your body – and mind, for that matter – on quite a ride, here’s your essential guide to pregnancy hormones.
The first hormone to make a grand entrance after conception is ‘human chorionic gonadotropin’ (hCG). This chemical is also known as the ‘whistleblower of pregnancy’ since it’s detected by a blood or urine test to confirm you’re brewing a babe in your belly. HCG keeps other pregnancy hormones, oestrogen and progesterone, at appropriate levels until the placenta has grown enough to take over this important responsibility. During the first ten weeks of pregnancy, your hCG levels will double every two days.
Need to pee umpteen times a day? HCG elevates the blood supply to your pelvis, which, in turn, makes your bladder desperate to excrete even the tiniest droplet of urine. Fortunately, this maddening condition only lasts the duration of your first trimester (‘phew’, you’re probably thinking?!)
Other physical symptoms of early pregnancy, such as morning sickness, extreme fatigue and breast tenderness, can be pinned on our pal hCG. You’ve heard about nausea in pregnancy, but you didn’t think it would be this bad? Misleadingly, queasiness can actually occur at any time of the day and last for hours on end. Sickness tends to spike around week eight to ten when your hormone levels are at their highest. Thankfully, this often-unpleasant symptom of pregnancy should dissipate once the second trimester begins.
That’s not all folks! HCG can take you on one hell of an emotional rollercoaster too. You may experience worry, delight, excitement and fear all in the space of half an hour. Prepare to be tearful one minute, and full of happiness the next. Oh, and get ready for those inevitable outbursts at TV ads, an old, nostalgic song on the radio, and pictures of babies in oh-so-cute clothing. Don’t worry though – you have no need to question your sanity. This is very normal behaviour (even if you do find yourself doing all sorts of strange things!)
In early pregnancy, this hormone is made by the ‘corpus luteum’ – a cyst on the ovary that produces progesterone until ten weeks, after which point the placenta takes over. In the first trimester, the amount of progesterone in your body increases exponentially and then stabilises. This hormone plays a particularly vital role in pregnancy; it helps your immune system tolerate and process foreign DNA, and keeps the uterus muscles relaxed.
In addition, progesterone relaxes blood vessels throughout your body, lowering blood pressure and leading to occasional bouts of dizziness. Progesterone also triggers those not-to-glamorous digestive symptoms of pregnancy, including acid reflux, heartburn, vomiting, gas, belching and constipation. Oh, the joys! On a more positive note, this hormone increases hair growth, which can explain why your mane is looking so gorgeous these days!
Can’t remember where you parked the car? Or, even what you just ate for breakfast? In the early stages of pregnancy, progesterone brings about another baffling symptom otherwise known as ‘baby brain’. This hormone prompts forgetfulness and fogginess. Again, there’s no need to freak out and ask ‘what’s on earth’s wrong with me?!’ Just remember feeling fuzzy is normal – try to laugh it off and get on with your day.
Similar to progesterone, the corpus luteum secretes oestrogen until the placenta is strong enough to take over. This chemical signal plays a key function in pregnancy; it stimulates the hormone production in the foetus’ adrenal gland, as well as increasing the size of your uterus, enabling it to respond to oxytocin – another essential pregnancy hormone. At the end of your first trimester, your oestrogen levels will peak, and then steadily plateau.
Increased appetite, skin changes, nausea and spider veins can be largely attributed to high oestrogen levels during pregnancy. That said, some women are lucky enough to experience that much lusted after ‘pregnancy glow’ – one definite upside of this hormone.
There’s a common misconception that oxytocin triggers labour (Pitocin – a synthetic form of oxytocin – is the drug typically given to induce labour). But, in truth, your levels of this chemical don’t spike when you go into labour – it’s just that the uterus becomes hypersensitive to oxytocin as you near the end of your pregnancy. Importantly, this chemical stimulates your nipples to excrete milk and helps stretch the cervix.
This hormone is responsible for loosening up the pelvic bones in preparation for delivering your little babe through the birth canal. Did you know your body produces ten times the normal amount of this hormone during pregnancy? The downside of this chemical is that your shoulders, hips, knees and ankles may feel a little ‘looser’, which could incite inflammation, pains, aches and even clumsiness.
This all-important milk-producing hormone – a chemical that will increase ten to twenty times during your pregnancy – prepares your breast tissue for the release of milk and lactation.
Take home message
Whether you’re bawling your eyes out at a Pampers advert or suffering from a severe case of ‘baby brain’, keep in mind that it’s normal to experience fluctuations in your emotional and physical wellbeing during pregnancy. Accept that you’ll be happy at times, and want to pull your hair out at others. Understand it’s not you – it’s your hormones, seriously.