Usually, labor and delivery occur without any problems. Serious problems are relatively rare, and doctors can usually detect and treat them. Regular visits to a doctor or certified nurse midwife during pregnancy are important to have a healthy pregnancy and to detect problems if they occur. Some problems develop suddenly and unexpectedly, so pregnant women should call their doctor or midwife if something seems wrong (such bleeding, decreased fetal movement).
Examples of problems (complications) that can develop or become evident only after a pregnant women goes into labor or during delivery include:
Intraamniotic infection (infection and resulting inflammation of the tissues around the fetus)
Shoulder dystocia (the fetus's shoulder lodges against a woman's pubic bone, and the baby is caught in the birth canal)
Umbilical cord prolapse (the umbilical cord comes out of the birth canal before the baby)
Uterine rupture (rare)
Amniotic fluid embolism (the fluid that surrounds the fetus in the uterus enters a woman’s bloodstream, sometimes causing a life-threatening reaction)
Postpartum hemorrhage (excessive uterine bleeding at delivery)
Placenta accreta (a problem with the placenta that may be discovered during pregnancy or only after delivery of the baby)
Uterine inversion (a uterus that is turned inside out)
When complications develop, alternatives to spontaneous labor and vaginal delivery may be needed. They include
Labor started with medications (induction of labor)
Forceps or a vacuum device (called operative vaginal delivery) to deliver the baby
Timing of Labor and Delivery
The average length of pregnancy is 40 weeks, counted from the first day of the last menstrual period. The due date is set at 40 weeks, but this is an estimate. Most women do not deliver exactly on their due date, but some do.
Labor may start
Too early (preterm labor): Before the 37th week of pregnancy
Late (postterm): After the 42nd week of pregnancy
If a baby is delivered too early or too late, there is a risk of health issues.
Labor may be early or late because a woman or fetus has a medical problem or the fetus is in an abnormal position.
Determining the length of pregnancy can be difficult because the precise date of conception often cannot be determined. Early in pregnancy, an ultrasound examination can help determine how far along the pregnancy is. In mid to late pregnancy, ultrasound examinations are less reliable in determining the length of pregnancy.