Progesterone is sometimes referred to as P4 or Prog, but is known as the “pregnancy hormone.” Progesterone is a hormone created early in pregnancy by a cyst on the ovary called the Corpus Luteum. This cyst of the ovarian follicles continues to produce progesterone for 10 weeks during pregnancy. After those initial weeks, then the placenta takes over producing progesterone. During the first trimester, progesterone levels rise exponentially, but plateau shortly after. Progesterone is key to creating a perfect environment for the ovaries to harbor the fetus by keeping the uterus muscle relaxed and helping the immune system tolerate foreign DNA. When a woman undergoes IVF or another fertility treatment, this hormone will sometimes need to be supplemented. Women’s ovarian follicles might also be poorly developed and may not secrete enough progesterone on their own. In these circumstances, progesterone will need to be supplemented as well.
The hormone progesterone is secreted during early pregnancy and prepares the uterus for pregnancy. It causes the luteal phase to start and transforms the endometrium (uterine lining) by thickening it to receive an embryo. The embryo is the result of the female’s egg when it’s fertilized by the male’s sperm. When pursuing pregnancy, the fertilized embryo will reach the uterus normally 5 days after ovulation. Then two days later, it will attach to the uterine wall. After it attaches to the uterine wall, this is when progesterone levels peak. If undergoing IVF, the client would normally go through progesterone supplementation to help encourage the fertilized embryo to attach to the uterine wall.
When a woman is pregnant they produce hCG (human chorionic gonadotropin hormone). This is a signal to the ovaries to continue to produce progesterone. hCG prevents the onset of her menses (the blood and matter discharged during ovulation) and enables a woman to become pregnant. Progesterone then continues to be produced, nurturing the fetus as it starts to grow. After 8-10 weeks of pregnancy, the placenta takes over progesterone production and increases production until the baby is born.
Estrogen, the primary female sex hormone, stimulates the growth of tissue inside the uterus. To prevent uterine overgrowth, progesterone slows this activity and redirects growth elsewhere. Your fertility doctor will augment your natural production of progesterone to avoid early miscarriage and help maintain a healthy level of progesterone during pregnancy.
Other benefits include:
In 1999, the FDA found that using synthetic progesterone may be associated with birth defects. Synthetic progesterone is primarily derived from the male hormone testosterone. Be very careful when undergoing progesterone treatments to make sure you’re not using synthetic progesterone. Always consult a doctor when considering taking progesterone during pregnancy.
Common side effects when using progesterone:
Talking with your health care provider is important when deciding what supplementation is best for you. Progesterone supports implantation and pregnancy and is an important part of infertility treatment. Health care providers usually have a preference based on experience with other methods that can help you decide which supplementation is best for your infertility treatment.