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How pregnancy hormones work
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The four main pregnancy hormones

Let’s take a more detailed look at each of the 4 main hormones (hCG, hPL, oestrogen and progesterone). At how they provoke reactions in the body during pregnancy, how they work, what problems they can cause and how to accommodate for them:

hCG during pregnancy

The four main hormones
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Human chorionic gonadotropin (or human chorionic gonadotrophin) is produced by the body immediately after fertilization, even before the embryo appears. Its main job is to allow the fertilized egg to ‘fix’ and remain within the uterus.

A blood sample can detect hCG levels just 8 days after conception, and 2 weeks after, traces can be found in urine. The hCG hormone reaches its maximum levels of concentration around the 3rd month of pregnancy, then diminishes until around the 20th week, remaining at a stable level after this time until birth.

High hCG concentration levels affect the central nervous system and cause that infamous morning sickness and nausea. They also make the stomach’s walls dilate meaning that ingested food transits the digestive system slower, and can cause indigestion and vomiting. It is estimated that between 50 and 70% of pregnant women suffer from nausea. However this is considered a good sign - hCG hormone protects pregnancy. Fatigue and sleepiness are also possible symptoms.

To steer clear of these various problems, we advise you to:

  • Avoid an empty stomach, but not to eat too much at once either! Ideally eat 6 small meals a day to help prevent stomach distension.
  • Avoid drinks during a meal, especially fizzy drinks – the fizz can cause distension.
  • Avoid black tea, coffee or any cola-based sodas, rich in xanthine, an ingredient which can make symptoms worse.
  • Think positively: feelings of nausea should stop after the 3rd month of pregnancy.
  • Drink water or acidic fruit juices but not during meals. Lemon or pineapple juices are good and low-calorie to boot. You can drink up to 1.5 litres of liquids a day.
  • Nibbling on crackers in the morning, as soon as you wake up, can help to reduce morning sickness. This way, you shouldn’t feel particularly nauseous when brushing your teeth.
  • Take a nap in the day if you’re tired, but don’t overdo it. Keep your mind occupied with pleasant tasks: boredom or feeling upset can cause apathy or even depression.

HPL during pregnancy

Human placental lactogen increases throughout the pregnancy, reaching its highest point when the baby is born.  As its name indicates, this hormone prepares a woman’s body for breastfeeding. Between the 24th and 28th week, increases in hPL impede the action of insulin, a hormone produced in the pancreas and in charge of "burning" all the sugar we ingest to transform it into energy.  

If the pancreas cannot control blood sugar levels (in 2 to 5% of pregnancies), the pregnant woman develops temporary diabetes, known as gestational diabetes, which requires specific treatment. The faster this diabetes is detected, the fewer risks there are for both mother and child.

 Checking for gestational diabetes:

  • Make sure your doctor gives you a glucose test on an empty stomach and a glucose tolerance test. These are good indicators for early detection of diabetes. These tests should be repeated at some point between the 28th and 3nd week of pregnancy.
  • In most cases, a healthy balanced diet – along with suitable physical exercise – is enough to bring blood sugar levels back to normal. Cases requiring insulin injections are rare.
  • Excessive weight gain is another risk factor for contracting diabetes. Weight gain should therefore be controlled.
  • Diabetic parents in the family, a previous pregnancy giving birth to a baby weighing over 4.5kg or twins and excessive quantities of amniotic fluid are all higher risk factors for developing gestational diabetes.

Oestrogen during pregnancy

Oestrogen is already present in a woman's body before pregnancy, but it increases significantly after conception, reaching its highest level just before birth. It is one of the rare hormones that actually makes a pregnant woman look radiant! It makes hair shinier and skin clearer. Hair grows rapidly and doesn’t fall out. This is a temporary effect however as after the birth, hair loss can be an issue.

Oestrogen promotes blood irrigation, making skin look radiant. But this can also cause gums to bleed due to the combination of oestrogen and progesterone. Oestrogen multiplies the number of cells, increasing the thickness of gums; progesterone causes swelling in this area.

To avoid this type of problem:

  • Use a soft- and flexible-bristled toothbrush.
  • Use dental floss (at least once a day) for increased dental hygiene.
  • If even simple brushing is painful, don’t wait for the pain to subside, go and see your dentist.

Progesterone during pregnancy

The name progesterone is quite literal: pro (in favour of) and gesterone (meaning gestation). So progesterone's main job is to promote pregnancy. If the body lacks progesterone, an egg can be fertilized but will not “fix” in the uterus.

Right from the start of pregnancy, a woman will notice an increase – even slight – in breast size: this is due to progesterone. Breasts can even be sensitive to touch, a little swollen and more painful. This change is important; it means the body is preparing for breastfeeding.

Progesterone levels gradually increase during pregnancy and experience a peak at the time of birth. Progesterone is indirectly involved in the secretion of a hormone called relaxin (see next section), contributes to feelings of heavy legs and the appearance of varicose veins... Poor circulation means that blood sent by the heart to the legs has difficult returning and tends to cause blood vessels to dilate.

And that’s not all. Progesterone makes the intestines work at a slower pace, making bowel movements more difficult. Added to this, mood swings causing higher emotional instability, forgetfulness and even depression (20 to 40% of pregnant women suffer from some form of mild to more severe depression during pregnancy).

Posted 01.03.2011


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