The truth about pregnancy hormones

There is nothing that can prepare us for the myriad of hormonal and psychological changes that occur when we become pregnant – it’s truly unique in the life of the expectant mother!

And it’s fair to say so are the effects, which differ between us all, leading us to be totally unpredictable in how we feel, act and respond, almost on a daily basis.

So here’s some information on the important hormones you may be interested in knowing more about!

human chorionic gonadotropin (hCG.)
The first one to take note and generally the one hormone that shouts pregnancy, is human chorionic gonadotropin (hCG.) It’s also known as the ‘announcer of pregnancy’ as this is the hormone that’s picked up by a urine or blood test to determine pregnancy.

In a ‘normal’ pregnancy, the level of hCG approximately doubles every two days during the first 10 weeks. hCG keeps the other pregnancy hormones known as estrogen and progesterone at their appropriate levels until the placenta has developed enough to take over this function (at the end of the first trimester.)

hCG is thought to be responsible for several of the symptoms experienced in early pregnancy, not least morning sickness. Morning sickness tends to peak around the eighth to tenth week of pregnancy when hormone levels are highest. It should (though not always) then taper off as the second trimester begins.

Another side effect of hCG is your developing sensitive bladder, which can stay with us throughout the pregnancy. hCG is responsible for increasing the blood supply to your pelvis, which, in turn, makes your bladder want to get rid of the tiniest amount of urine. Although it generally eases after the first trimester it may return later as your baby gets bigger and starts pushing on your bladder.

Estrogen and Progesterone
“The big two,” the main culprits that are responsible for the bulk of pregnancy symptoms experienced and continue to play a main role are estrogen and progesterone.

Estrogen is produced by the ovaries and later (post first trimester) by the placenta and helps the uterus grow, maintains the uterine lining (where your baby is), steps up blood circulation, and activates and regulates the production of other key hormones.

In early pregnancy, estrogen promotes the growth of your breasts and later on, it helps develop their milk-making machinery. Estrogen also triggers the development of your baby’s organs and regulates bone density in their developing arms and legs.

Progesterone (a "pro-gestational" hormone, hence the name) is manufactured first by the ovaries and then by the placenta starting around the second trimester. Progesterone keeps the placenta functioning properly and the uterine lining healthy and thick, and it stimulates the growth of breast tissue. It also restricts pre-pregnancy's natural contractions of the smooth muscle of the uterus, allowing your baby to grow in your womb.

Here are their main side effects:

  • Breast soreness and sensitivity, as experienced early on in pregnancy.
  • The sensitivity of smell.
  • Fatigue is due to progesterone and according to some, can have the same effect on the brain as some sleeping tablets! Especially in the first semester, it does explain the drowsiness and complete exhaustion.
  • Bloated feeling due to the relaxing of the bowel muscles
  • Progesterone also softens cartilage, which can result in hip and pubic bone pain.
  • Estrogen can cause skin to be more sensitive
  • Mood Swings
    Of course, we know that not all pregnancy symptoms are physical. Pregnancy is apt to turn any formerly sane and seemingly competent women into a rather unpredictable creature (and vice versa!)

    Apparently, it’s down to the hormones affecting our levels of neurotransmitters, the brain chemicals that regulate mood and again affects everyone differently. 
You’re most likely to experience these changes at around six to 10 weeks, and then again in the third trimester as your body prepares for labour and delivery.

    The hormones circling are certainly partly responsible for your already complex emotions feeling heightened. It’s fair to say you can expect to feel anything from mood swings of happiness to depression or states of anxiety (all on the same day!)

    The best advice, although it’s difficult to follow, is to try to work with your emotions and accept what is happening is down to your hormonal changes, which are especially prevalent in the first trimester.

    Also, talking about your feelings and the changes occurring with your partner can help and may even put you both at ease, especially as they may already feel helpless if you are suffering with pregnancy symptoms.

    Ultimately for most pregnancies, every day can bring a completely new feeling – one day we can feel on top of the world, and the next exhausted and staying close to the bathroom! Instead of being paranoid or psychoanalysing, it’s best just to blame it on the hormones and deal with it as best you can.

    What would you add to our list with your experiences of hormone changes? We’d love to hear your experience.

    Be the first to receive latest support tips, news and offers from our partners, alongside finding out what www.mumandbabyonline.co.uk has to offer, register for free here.

    Whilst we welcome feedback on this blog, we will not tolerate any abuse or misuse. Please respect the views and feelings of others. The content and advice offered is based on general recommendations and health-care professional suggestions and is designed to be used as a guide and discussion piece. It is not a substitute for examination, diagnosis or treatment by a qualified health-care / medical professional. If in doubt, always consult your doctor or health-care professional.

    Related Posts
    Nutrition for New Mums
    Keeping Your Baby Safe In The Sun
    What to eat (and avoid) when pregnant

    Leave Your Comment