What's going on during a woman's menstrual cycle is much more complex than you might think. The cast of characters during that 21-to-35 day program includes the hypothalamus, the pituitary gland, and the hormones estrogen, follicle stimulating hormone (FSH), luteinizing hormone (LH) and progesterone.
Eggs don't just drop from a woman's ovaries like apples from a tree -- the brain kicks off a carefully orchestrated process that results in a small window for an egg to be fertilized by sperm.
At the beginning of the process, one hormone triggers eggs to mature, followed by another that tells the egg to begin its road trip down the fallopian tube. Yet another hormone prepares the uterus to be as hospitable to a fertilized egg as possible. If there is no union of egg and sperm, hormone levels change and the uterus gets rid of that cushiony lining, which is what a period is.
With so many steps, there are opportunities for mishaps -- which means the possibility of infertility.
The misplaced cells that characterize endometriosis, for example, respond to the hormones telling them to swell, but they can't be shed through the vagina. The tissue and blood have nowhere to go except inside the body, where they can cause scarring and blockage of the fallopian tubes [source: WomensHealth.gov]. PCOS messes with a woman's hormones, which throws the whole process off balance. Certain types of fibroids can change the shape of the uterus, and PID damages the fallopian tubes, resulting in an egg's inability to travel and possibly a life-threatening ectopic pregnancy, when a fertilized egg grows in the wrong place [sources: Parker; CDC].
The good news is that the more we know about conditions that affect a woman's fertility, the greater the chances of finding a treatment that works. Today, there are more options for infertility treatment than ever before. Depending on the cause of a woman's abnormal cycle, the solution may be as simple as weight control. But you won't know until you talk to a doctor, so make the appointment today.