How pregnancy hormones can affect you

How pregnancy hormones can affect you

As pregnancy gets underway, a storm of hormones floods the body. Aside from puberty, you’ll have never felt such a surge – as your body changes in some odd and unpleasant ways. While hormones aren’t responsible for every bloat, blemish, or mood swing during pregnancy – the truth isn’t that far off.

Understanding these tumultuous chemicals, i.e., pregnancy hormones effect, is essential to getting through the nine-month rollercoaster. From progesterone to oestrogen, we explore how these powerful pregnancy hormones affect your body and mind.

Let’s get started!

What hormones are released during pregnancy?

Most of the hormones released in pregnancy are found throughout your life. Yet, during the nine months, your regular cocktail of chemicals becomes a little more potent, and a few new ingredients are added into the mix:

  • Oestrogen, produced by the early embryo and later the placenta, rises during pregnancy and then plateaus. It’s responsible for the baby’s development.
  • Progesterone also rises during the first trimester. It helps maintain your uterus and prevents your immune systems from attacking the baby.
  • Human chorionic gonadotropin (HCG) is how pregnancy tests know you’re pregnant. Produced by the placenta, it rises during the first 60 to 90 days and is one of the pesky causes of morning sickness. It also causes you to feel more tired and a constant lack of energy.
  • Prolactin is released late in pregnancy to ready your breasts for milk production.
  • Relaxin, as the name suggests, helps your joints relax before birth.
  • Oxytocin is responsible for a range of functions: it stimulates milk production, prepares the cervix for labour, and encourages you to bond with your baby. Breastfeeding your baby soon after birth has the additional benefit of stimulating oxytocin which also helps your uterus to contract and prevent excessive blood loss.

How do pregnancy hormones affect your body

Pregnancy hormone’s effect on the body is a subject for several textbooks. Oestrogen works like a conductor, regulating your baby’s development, promoting breast tissue growth, maintaining your uterine lining, and much more.

Progesterone, alongside Relaxin, can trigger heartburn, constipation, indigestion, and bloating. But this troublesome twosome also softens the ligaments and cartilage making labour possible.

How to recognise the signs of hormones during pregnancy

While most pregnancy hormone’s effects are hidden from view, you may notice:


  • Morning sickness
  • Digestive problems
  • Increased urination
  • Breast growth and tenderness
  • Body hair growth
  • Mood changes
  • Low blood pressure and dizziness

What you can expect in each trimester

Pregnancy is like a three-course meal, with no stage like the last. The hormones regulate your body’s response and your baby’s development during these stages.

Here’s what you can expect:

In the first trimester, you’ll feel a surge of hormones coursing through your bloodstream. Mood swings may leave you irritable, while high progesterone levels can trigger morning sickness. Your breasts may feel tender, and your nose can become runny. Oh, and the HCG will cause a positive pregnancy test.

As the second trimester rolls around, your nausea tends to dissipate. Hold the celebrations. In its place comes pelvic pain, alongside dark skin from an uptick in melanin production – the so-called “mask of pregnancy”. During this period, you can develop gestational diabetes; your midwife or doctor will test for this condition.

Last but not least, the grand finale: the third trimester. As you approach labour, pelvic pain can intensify. Heartburn is a common symptom as Progesterone and Relaxin loosen up muscles of the oesophagus that leads into your stomach. If your stomach contents are quite acidic they can reflux back up your oesophagus and cause an acid reflux. It’s advisable to eat small, frequent meals. Avoid spicy or fatty foods. Even very cold liquids can cause a reflux. Breasts may produce their first milk, and feet tend to swell.

No sooner have you reached the pinnacle then labour begins – and then there’s the flurry of postpartum hormones to enjoy! For further information, speak to your midwife or doctor.

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A regular pattern of movements is a key indicator of your baby's well-being during pregnancy.

Women don't always know how to recognise a regular pattern of movements for their baby and don't know what they should be checking for. This leads to increased anxiety. When they do think something isn't quite right, they don't feel confident and they doubt themselves so don't seek advice straight away.

We're developing a device that will monitor your baby's movements during pregnancy from 24 weeks onwards so that you can have a better understanding of your baby's regular pattern of movements.

To read more helpful blogs visit our pregnancy blog.

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