Pregnancy hormones are chemicals secreted by the endocrine glands that control the physiological process of pregnancy, from conception to delivery.
List of pregnancy hormones and their functions;
1. Human chorionic gonadotropin; made by the placenta forming cells chorion /placenta, it is found in the blood after 9-10 days of conception and in the urine 12- 14 days.
It nourishes the fertilized egg (corpus luteum) after it is fertilized and implanted in the uterus.
2. Estrogen; this hormone is produced for the first 12 weeks of pregnancy, after which the placenta takes over its production
Its main function is to stop lactation, ovulation and menstruation, by inhibiting the activities of prolactin, follicle stimulating hormone and luteinizing hormone.
It also acts on the ductal system of the breast causing growth in preparation for lactation, it makes the uterus grow, and causes softening and relaxation of pelvic girdle.
3. Progesterone; initially secreted by corpus luteum, and later by the placenta.
Its main function is to maintain the endometrium by causing endometrial glands to secret nutrients used by the fetus. It also reduces the maternal immune response so that the baby is not rejected.
It relaxes the muscles in other to prevent premature expulsion of fetus and caused development of milk glands in readiness for lactation
4. Prolactin; secreted by maternal anterior lobe of pituitary gland, responsible for lactation after delivery when the levels of estrogen and progesterone are reduced.
5. Relaxin; softens the cervix, causes relaxation of the pelvic ligaments and muscles thereby inhibiting muscular contraction.
6. Human placenta lactogen, produced by placenta, its main function is to regulate feto-placenta growth, by converting fat in maternal diet to energy for fetal use.