Abnormal menstrual cycles can occur at any point in a woman's reproductive years. These periods of abnormality can occur for any reason, from stress to influenza. However, some events that happen in a woman's life, such as childbirth, can cause periods to be abnormal for a certain amount of time.
Hormones Before Childbirth
The menstrual cycle is controlled by a combination of the luteinizing hormone, follicle-stimulating hormone, estrogen and progesterone. Luteinizing and follicle-stimulating hormone are both released from the pituitary gland, located in the brain. The release of these hormones causes the reproductive organs to produce and release estrogen and progesterone, which are both used to control the ovulation and menstruating process. These hormones secrete at low levels until an egg is matured for fertilization. Once this occurs, levels of estrogen, progesterone and luteinizing hormone surge, causing a follicle to rupture and release the matured egg. According to the American Pregnancy Association, if this egg is not fertilized within 12 to 24 hours, a few weeks after the egg's release, hormone levels will sharply decrease and menstrual bleeding will occur. As stated by Merck Manuals, this bleeding lasts for three to seven days and reoccurs every 25 to 36 days.
Bleeding After Childbirth
When conception occurs, the reproductive hormones will remain elevated until giving birth. This keeps the menstrual cycle from occurring during the pregnancy. After childbirth, the hormone levels drop, although menstruation may take up to three weeks to begin. After giving birth, some women will experience a bleed immediately; this is not menstrual blood. After giving birth, the uterus contracts, causing the expulsion of blood, mucus and tissue as it returns to its normal size.
Time Frame
Once the baby is born, menstrual bleeding should occur within a month, although this bleeding may be heavier, lighter, longer or shorter than usual, and this irregularity may last for months. Women with medical conditions such as endometriosis or polycystic ovary syndrome may continue to have irregular cycles, as they did pre-pregnancy. However, in some women, pregnancy may regulate the body, causing the menstrual cycles to become normal after childbirth.
Considerations
Women who breastfeed may take longer to menstruate after giving birth than women who don't. After birth, a hormone is activated that causes the breasts to produce milk, but it also stops ovulation from occurring. As long as a woman is actively breastfeeding, this hormone's level will remain high. When she stops breastfeeding, menstruation will resume, although the exact time that it will begin differs from woman to woman.
Warnings
If bleeding begins and there is extreme pain, large blood clots, profuse bleeding or bleeding that is bright in color, contact a physician immediately.
