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We know this is probably not a new hormone for most mums-to-be, because it’s always busy at work in the female body. However, during pregnancy this hormone ups its game and does even more than normal.

Estrogen is actually a group of 3 hormones: estrone, estradiol and estriol (which the placenta produces). All three are important for the development and functioning of your sexual organs and your pregnancy. These hormones are mainly produced in the ovaries, adrenal glands and your fat tissues.

box of tissues

Increased estrogen levels during pregnancy will mean you need to have a good stock of tissues at the ready.

Estrogen's first job occurs during weeks 1 and 2 of pregnancy when it thickens your uterine lining and signals for your follicle to release the egg so that it can be fertilised. Afterwards, estrogen plays an important role in the growth of your uterus, the maintenance of your uterine lining in which your baby is implanted, blood circulation, the activity of other hormones, lactation and the growth and development of your baby’s organs and bones. Moreover, it works together with progesterone to prevent additional ovulation during your pregnancy. Estrogen is one busy group of hormones!

What does estrogen do to your body?

Despite how wonderful estrogen is in the development of your gorgeous baby, it, together with progesterone, is responsible for the majority of your annoying pregnancy symptoms including:

  • Breast soreness and sensitivity in your first trimester
  • Heightened sense of smell, which can influence cravings or make certain smells repulsive
  • A bloated abdomen, because it relaxes your bowel muscles

    woman holding breasts

    Increased estrogen makes your breasts super sensitive during the first trimester

  • Sinus congestion and a nasal drip, as it increases blood flow to your mucous membranes causing them to swell and soften
  • Itchy skin and rosy features, also due to increased blood flow
  • Hyperpigmentation or the discolouration of your skin, such as the darkening of your nipples and areola and the white line down your abdomen which precedes the linea nigra that will appear in week 23 of your pregnancy. On the plus side, your face will probably look a bit more tanned than normal, but it is also means you’ll need to put on sunscreen every day, because your skin is going to much more sensitive to sun exposure.

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