Before looking at oral birth control, let’s review reproduction. Ovaries, or egg sacs, are attached to the uterus by means of fallopian tubes. The lower part of the uterus is known as the cervix. Each month an ovum, or egg, is released from the ovary into either the right or left fallopian tube. If a sperm, released by the woman’s partner near the cervix, traverses the uterus to fertilize this egg, the fertilized egg travels along the fallopian tube into the uterus. There it implants in the endometrium, which lines the endometrium, and spends the next nine months growing and developing into a full-fledged infant, ready for birth.
Oral birth control is composed of female hormones taken in pill form. There are two basic types of female hormone, estrogen and progesterone, each of which becomes prominent at a different time during the 28-day cycle. The mini pill is composed of progestin, a form of progesterone only, while combination estrogen and progesterone pills offer a wider variety.
The mini pill–all mini pills are the same. They thicken the cervical mucus, thin the endometrium, and slow the egg’s trip through the fallopian tube, making it difficult for the sperm to reach the egg. The mini pill can be taken by patients at high risk for blood clots, migraine attacks, high blood pressure, or hypertension (high blood pressure). This type of pill lowers the risk of endometrial cancer and is less likely to interfere with breastfeeding than combined pills.
Mini pills have disadvantages as well. If a patient takes a pill more than three hours late, she needs to use another form of birth control for the next two days. Progestin-only pills can cause irregular menstrual periods, ovarian cysts, lowered libido, tender breasts, acne, weight gain, depression, and unwanted hair growth. There is a slightly increased risk of ectopic, or out-of-place, pregnancy developing.
Combination pills–prevent release of the egg from the ovary. Should an ovum be released, then the combination pill would work like a mini pill–slowing the egg’s progress and blocking the sperm by thickening the cervical mucus and thinning the endometrium. Combination pills offer relief from several problems. Women with polycystic ovaries use combination pills to treat hirsutism. Patients’ periods grow shorter, lighter, and more predictable, or disappear altogether, along with the anemia that can accompany heavy bleeding. Dysmenorrhea, or severe menstrual cramps, can be relieved, as can premenstrual syndrome. The pain of endometriosis, in which endometrium lining the uterus grows outside the uterus, can be relieved. There is a lowered risk of ovarian, endometrial, and colorectal cancer. Bone mineral density improves, lowering the danger of fractured bones.
Some side effects of combination pills, including nausea, headaches, breast tenderness, and breakthrough bleeding, can decrease with continued use. Others can be more problematic. Elevated blood pressure can lead to heart attacks and stroke, particularly in smokers. Blood clots in the legs can migrate to the lungs, interfering with breathing. Liver disorders and gallbladder disease are also possibilities.
Patients need to discuss their health histories and have physical evaluations performed by their physicians to find the best, safest oral contraceptive available.