All about your hormones

Pregnancy hormones have some unpleasant side effects: mood swings, your chest feels like it’s on fire, and your teenage pimples are back. But there are also some pleasant surprises to look out for, writes Shanda Luyt

EVEN BEFORE CONCEPTION, your hormones collaborate to create a favourable environment for your baby – and as soon as egg meets sperm, these chemical messengers go all out to ensure that the right things happen at the right time, so that your nine months run smoothly and healthily.

All these changes are the result of the more than 30 hormones coursing through your veins while you’re pregnant. You will certainly feel their effect, physically and emotionally.

The real job of these hormones is to ensure Mom and Baby’s health.

HCG: THE PREGNANCY ALARM

One of the first hormones to appear has the intimidatingly long name human chorionic gonadotropin (hCG), but it’s also commonly known as the pregnancy hormone. As it’s only present during pregnancy, this is the hormone the tests look out for. It presents in your blood and your urine. Whether you do a home test or have a blood test done at the doctor – if hCG is present, you’re pregnant!

A few days after the fertilised egg attaches itself to the uterine wall, the brand-new placenta starts producing hCG. The amount of hCG increases at an incredible rate and reaches a climax at day 70. Thereafter, it subsides, and the hormone keeps a low profile for the rest of your pregnancy.

The most important task of this hormone is to ensure the continued production of the steroid hormones oestrogen and progesterone. Without it, your progesterone level will go down, and you’ll have your period again.

As the placenta becomes more mature and is able to take over the production of oestrogen and progesterone, hCG declines. If you’re looking to blame something for that awful morning sickness

and the incredible fatigue that hits you during your first trimester, hCG is the one. It’s also the hormone that sends you to the loo every five minutes, and it suppresses your immune system to decrease the risk of your body rejecting the baby – which makes you more susceptible to illnesses during this time.

OESTROGEN: BETTER BLOOD FLOW AND SORE BOOBS

Oestrogen is perhaps the most wellknown female hormone and is produced throughout your pregnancy. As your pregnancy progresses, increasing amounts of oestrogen will be in your system. This group of hormones is usually produced in your ovaries, but during gestation, the placenta also produces it, and it plays a key part in a healthy pregnancy. It promotes blood flow to the uterus, supports uterine growth and maintains the uterine lining – all to ensure your baby has the ideal little spot to grow. Oestrogen helps with better blood circulation and also ensures that your blood volume starts increasing by 10 weeks. It also activates and regulates the production of other key hormones, including progesterone.

BABY ALSO BENEFITS FROM OESTROGEN

Oestrogen helps to develop baby’s organs and is at a later stage partially responsible for the development of female genitalia. It also regulates the bone density of Baby’s developing arms and legs. Oestrogen is one of the hormones that causes you to have sore or tender boobs early in your pregnancy and that makes them grow fuller – all in preparation for breastfeeding later. And while oestrogen is taking care of so many things, it unfortunately has a few unpleasant side effects, such as the permanent blocked nose you sometimes have when you’re pregnant, and even headache and post-nasal drip. The extra supply of blood can also make your skin appear red and patchy and make your palms itch. Blame oestrogen (together with a few others) for the pigmentation that seems to be everywhere now: darker nipples, a brown line on your belly, and dark circles around your eyes.

PROGESTERONE: KEEPS BABY INSIDE

Progesterone also becomes very important while you’re pregnant, as it prevents your womb from spontaneously aborting by building up a “lining” that can support the placenta. This is, in turn, very important for Baby’s nutrient and oxygen supply. Progesterone is initially produced by the ovaries, but from the second trimester it’s also made by the placenta. Before you fell pregnant, your uterus often naturally contracted and moved, but in your pregnancy, progesterone helps to prevent these shenanigans. It helps your uterus to swell and make space for your growing baby. As your pregnancy progresses, your progesterone level rises – until just before birth, when it drops to give the uterus a chance to contract. Progesterone stimulates the growth of breast tissue, and together with oestrogen is responsible for tender boobs early on in your pregnancy.

AND NO, PROGESTERONE IS NOT ALL GOOD NEWS

All the progesterone in your body works with the hormone relaxin to influence the smooth muscles. This is why the valve between your tummy and your throat sometimes doesn’t work very well and you experience reflux, especially in your third trimester. Progesterone and relaxin can also soften cartilage, which loosens up joints and ligaments and can cause all kinds of hip and pelvic pains. It also relaxes the digestive system and bladder, which could lead to constipation and flatulence. It can cause your gums to bleed and give you acne for the first time since your teens. And it can make you sweat more than usual!

PROLACTIN: PRACTICE FOR BREASTFEEDING

Prolactin is responsible for the increase of milk-producing cells in your chest. While you’re pregnant, progesterone and oestrogen prevent milk production, but as soon as the baby is born, there’s a dramatic drop in the level of these hormones, and prolactin can start producing milk.

Prolactin increases gradually as your pregnancy progresses, and it’s said that the increasing oestrogen in your body helps with the production of this hormone. Prolactin later also helps prevent you from falling pregnant while you’re breastfeeding – but it’s definitely not a reliable birth control method, as many moms have had to find out to their shock and horror!

Of course, there’s also a less pleasant side: prolactin is indirectly responsible for all that extra fuzz on your face, belly and other body parts. Fortunately, the extra hair gradually disappears after the birth.

RELAXIN: RELAX AND ENJOY

Relaxin is released early in your pregnancy. It keeps the movements of the uterus in check and also softens the cervix in preparation for birth. As we’ve said before, it works with progesterone to allow your muscles, ligaments and joints to relax, especially in your pelvis. In this way, it prepares the way along which your baby will travel when he’s born. But the relaxation of all these muscles can be a bit painful and cause backache and other issues.

OXYTOCIN: THE LOVE DRUG

Oxytocin is sometimes called the magic hormone as it’s apparently responsible for the “caringness” of new moms and dads. On a more practical level it’s also responsible for the regular contractions of the uterus while you’re pregnant – like Braxton-Hicks contractions – and it’s the hormone that eventually kick-starts the contractions for your labour. Contractions during breastfeeding are also ascribed to oxytocin and will help your uterus to shrink back to its original size.

A FEW MORE...

Human placental lactogen (hPL) is also produced by the placenta and helps ensure the healthy development of the foetus. It helps your breasts prepare for nursing and to discharge colostrum – the super-important first milk. There’s a link between too little hPL and underweight babies because this hormone helps organise your metabolism in such a way that you channel more sugar to Baby. The thyroid hormone thyroxine helps you absorb more oxygen and collaborates with growth hormones to stimulate Baby’s growth. It’s also very important for the healthy development of Baby’s central nervous system. Thyroid stimulating hormone ensures the release of thyroid hormones that regulate your metabolism. Insulin controls the metabolism of food through you and your baby. As your pregnancy progresses, the insulin becomes less effective, as it is no longer able to keep up with the glycaemic load. This causes temporary gestational diabetes in up to two to four percent of women. Cortisol helps develop Baby’s lungs and increases gradually in the third trimester of pregnancy. On the other hand, studies have shown that too much cortisol, the body’s stress hormone, can interfere with the functioning of progesterone. It also plays an important part in learning and memory.