The number of eggs in a woman’s ovaries is determined by a) how many eggs she was born with, and b) how quickly they diminish during her lifespan. Because the total number of eggs she will ever have is established while forming in her mother’s womb, it is important to know if there are any factors in that prenatal environment that may affect the development of the eggs within the ovaries. Women with fewer eggs may suffer later in life from infertility or early menopause. Several studies have shown through experiments with animals that paracetamol taken by the mother while pregnant may have harmful effects on the reproductive function of the resulting female offspring. However, no studies have examined this in humans. In animal models, there are three proposed mechanisms for the effects seen in the female offspring: 1) disruption of the chemical signaling from the brain to the ovaries to induce puberty, resulting in earlier age of the onset of periods (which in human studies may be associated with earlier onset of menopause), 2) disruption of the natural menstrual cycle, resulting in shorter menstrual periods (which in human studies may be associated with earlier onset of menopause), and 3) formation of fewer follicles (eggs) in the ovaries, which can be approximated by measurement of anti-mullerian hormone (AMH) in the blood. Given that paracetamol is used worldwide as the analgesic of choice during pregnancy it is of critical importance that large-scale studies of humans be performed to investigate this association. This study will look at children of mothers who did and did not use paracetamol during their pregnancies and compare 1) the age of their first period, 2) how regular their periods are, and 3) their AMH levels.