Unless you are having an elective cesarean section, your body will go through labor to deliver your baby. Labor is a unique experience for each woman, but the process has some shared similarities. What causes you to go into labor can depend on your body, your baby and your doctor’s treatment.
Labor is the part of the pregnancy process that moves you from pregnancy to delivery. Through labor, your body will open the birth canal. Contractions will help push the baby from the womb through the cervix, through the vaginal passage and into your arms. Labor is often the most traumatic part of the delivery process for expecting mothers.
While no one knows the exact cause of labor, several factors come into play during this final stage of pregnancy. First, the level of prostaglandin, a hormone, increases, causing the cervix to soften. Second, the levels of the hormone oxytocin increase, triggering contractions. Third, the sac of membranes surrounding the baby ruptures. In a normal pregnancy, these factors can occur any time from two weeks prior to your due date to two weeks after it.
Doctors can replicate the normal labor process through artificial methods. First, a doctor will check whether the membrane still connects the amniotic sac to the uterus. If so, the doctor will use a finger to separate the membrane. This can cause the body to release more prostaglandin. Second, he may manually break the mother’s water, known as amniotomy. This involves using a plastic hook to rupture the sac of membranes surrounding the baby. Third, the doctor may administer a dose of prostaglandin to soften the cervix. The dose may be a pill the mother needs to swallow or a vaginal gel insert. Finally, doctors may give the mother an injection of pitocin — a form of oxytocin — to trigger contractions.
Preterm labor occurs when a mother has normal contractions before reaching the 37th week of pregnancy. Doctors may be able to stop the labor from progressing in some situations. While doctors do not know what causes preterm labor, also called premature labor, certain factors increase a pregnant woman’s risk. Women with a history of preterm labor or cervical abnormalities and mothers carrying multiple fetuses have an increased risk. Lifestyle choices, such as drinking alcohol, smoking, using drugs, taking some prescription medications and working long hours, may contribute to preterm labor. Race, age, income and medical history also affect a mother’s risk.
Some activities may contribute to the onset of labor, but study results tend to conflict. Intercourse may contribute to labor. While sperm, which contains prostaglandin, may help soften the cervix, a study at Ohio State University concluded that sexually active pregnant women carried their babies longer than those who abstained from sex during the weeks preceding the due date. Increasing activity levels may contribute to the causes of labor for some women.
Some cultures use black or blue cohosh to induce labor; however, the Office of Dietary Supplements (ODS) recommends that pregnant women avoid taking either supplement. One case report links cohosh to a baby’s neurological complications, according to the ODS. Castor oil is another substance that may induce labor. Most doctors recommend avoiding castor oil because it is a laxative. It may lead to meconium, or fecal matter, in the amniotic sac. Expecting mothers should avoid some herbal teas, as clinical trials are unclear on whether it is safe to consume certain herbs. Possibly unsafe herbs include nettles, yellow dock and alfalfa.
Braxton Hicks contractions, also known as false labor, can make a woman think labor has started. These contractions are usually irregular and do not thin or open the cervix. Typically, it takes more than one factor to cause labor. For example, some women begin dilating without the presence of noticeable contractions. Once the membranes rupture, 80 to 90 percent of women will begin labor within a 24-hour period, according to Cedars-Sinai.