During the menstrual cycle levels of the hormone estrogen fluctuate in a woman’s body. From around day 14 until when the period is due, estrogen levels in the body decrease, resulting in a proportionately higher level of testosterone. This imbalance in the hormones can result in the testosterone connecting to receptors in the skin more freely and increasing the size of your sebaceous glands, as well as the amount of oil that they produce. This in turn can lead to an increase in blockages of your hair follicles and a subsequent increase in acne.
During the first trimester of pregnancy, which starts from the first day of pregnancy and ends at week 12, women’s bodies release more of a hormone called progesterone. Progesterone has a similar effect on hair follicles as the hormones Testosterone and DHT, in that it causes the sebaceous gland to expand and produce more oil, which in turn can lead to more acne causing blockages forming.
It is important to remember that many acne treatments must not be used by pregnant women. If you are pregnant and are considering using an acne treatment, speak to your doctor or pharmacist first.