What Are Common Labor and Delivery Complications?
A pregnancy that has gone smoothly can still have problems when it's time to deliver the baby. Your doctor and hospital are prepared to handle them. Here are some of the most common concerns:
Preterm Labor and Premature Delivery
One of the greatest dangers a baby faces is being born too early, before his or her body is mature enough to survive outside the womb. The lungs, for example, may not be able to breathe air, or the baby's body may not generate enough heat to keep warm.
A full-term pregnancy lasts about 40 weeks. Having labor contractions before 37 weeks of pregnancy is called preterm labor. Also, a baby born before 37 weeks is considered a premature baby who is at risk of complications of prematurity, such as immature lungs, respiratory distress, and digestive problems.
Prolonged Labor (Failure to Progress)
A small percentage of women, mostly first-time mothers, may have a labor which lasts too long, sometimes called "failure to progress." Both the mother and the baby are at risk for several complications, including infections, if the amniotic sac has been ruptured for a long time and the birth doesn't follow.
"Presentation" refers to the part of the baby that will appear first from the birth canal. In the weeks before your due date, the fetus usually drops lower in the uterus. Ideally, for labor, the baby is positioned head-down, facing the mother's back, with its chin tucked to its chest and the back of the head ready to enter the pelvis. That way, the smallest part of the baby's head leads the way through the cervix and into the birth canal. This normal presentation is called vertex (head down) occiput anterior.
Because the head is the largest and least flexible part of the baby, it's best for the head to lead the way into the birth canal. That way, there's little risk that the baby's body will make it through the birth canal, but the head will get caught.
Some babies present with their buttocks or feet pointed down toward the birth canal. This is called a breech presentation. Breech presentations are often seen during an ultrasound exam far before the due date, but most babies will turn to the normal head-down presentation as they get closer to the due date.
Types of breech presentation include:
- Frank breech. In a frank breech, the baby's buttocks lead the way into the pelvis; the hips are flexed, the knees extended.
- Complete breech. In a complete breech, both knees and hips are flexed, and the baby's buttocks or feet may enter the birth canal first.
- Incomplete breech. In an incomplete or footling breech, one or both feet lead the way.
Transverse lie is another type of presentation problem. A few babies lie horizontally in the uterus, called a transverse lie, which usually means the baby's shoulder will lead the way into the birth canal rather than the head.
In cephalopelvic disproportion, the baby's head is too large to fit through the mother's pelvis, either because of the size or because of the baby's poor positioning. Sometimes the baby is not facing the mother's back, but instead is turned toward her abdomen (occiput or cephalic posterior). This increases the chance of a lengthy, painful, childbirth, often called "back labor," or tearing of the birth canal.
In malpresentation, the baby is not "presenting" or positioned in the normal way. In malpresentation of the head, the baby's head is positioned wrong, with the forehead, top of the head, or face entering the birth canal, instead of the back of its head. Sometimes a placenta previa (when the placenta blocks the cervix) may cause an abnormal presentation. But many times the cause is not known.
Abnormal presentations increase a woman's risk for uterine or birth canal injuries and abnormal labor. Breech babies are at an increased risk of injury and a prolapsed umbilical cord, which cuts off the baby's blood supply. A transverse lie is the most serious abnormal presentation, and it can lead to injury of the uterus, as well as injury to the fetus.
Your doctor will determine the presentation and position of the fetus with a physical exam. Sometimes a sonogram helps in determining the position of the fetus. When a baby is in the breech position before the last six to eight weeks of pregnancy, the odds are still good that the baby will change position before birth. But the bigger the baby gets, and the closer you get to your due date, the less room there is in the uterus for the baby to turn. Doctors estimate that about 90% of fetuses who are in a breech presentation before 28 weeks will have turned by 37 weeks, while over 90% of babies who are breech after 37 weeks will most likely stay that way.
Premature Rupture of Membranes (PROM)
Normally, the membranes surrounding the baby in the uterus break and release amniotic fluid (known as the "water breaking") either right before or during labor. Premature rupture of membranes means that these membranes have ruptured too early in pregnancy, meaning prior to the onset of labor. This exposes the baby to a high risk of infection.
Umbilical Cord Prolapse
The umbilical cord is your baby's lifeline. You pass oxygen and other nutrients from your body to your baby through the umbilical cord and placenta.
Sometimes, before or during labor, the umbilical cord can slip through the cervix after your water breaks, preceding the baby into the birth canal. The cord may even protrude from the vagina -- a dangerous situation because the blood flow through the umbilical cord can become blocked or stopped. You may feel the cord in the birth canal if it prolapses, and may see the cord if it protrudes from your vagina. This is an emergency: Call an ambulance and get to the hospital right away.
Umbilical Cord Compression
Because the fetus moves and kicks inside the uterus, the umbilical cord can wrap and unwrap itself around the baby many times throughout pregnancy. While there are "cord accidents" in which the cord gets twisted around and blocks blood supply to the baby, this is extremely rare and can't be prevented.
Sometimes the umbilical cord gets stretched and compressed during labor, leading to a brief decrease in blood flow to the fetus. This can cause sudden, short drops in fetal heart rate, called variable decelerations, which are usually picked up by monitors during labor. Cord compression happens in about one in 10 deliveries. In most cases, these heart rate changes are of no major concern, and the birth proceeds normally. But a C-section may be necessary if the baby's heart rate worsens or the baby shows other signs of distress.
Amniotic Fluid Embolism
This is one of the most serious complications of labor and delivery. Very rarely, a small amount of amniotic fluid -- the fluid that surrounds the fetus in the uterus -- enters the mother's bloodstream, usually during a particularly difficult labor or a C-section. The fluid travels to the woman's lungs and may cause the arteries in the lungs to constrict. For the mother, this constriction can result in a rapid heart rate, irregular heart rhythm, collapse, shock, or even cardiac arrest and death. Widespread blood clotting is a common complication, requiring emergency care.
Preeclampsia is a complication of pregnancy involving high blood pressure that develops after 20 weeks of pregnancy or shortly after delivery. Preeclampsia may lead to premature detachment of the placenta from the uterus, maternal seizure, or stroke.
Uterine Bleeding (Postpartum Hemorrhage)
After a baby is delivered, excessive bleeding from the uterus, cervix, or vagina, called postpartum hemorrhage, can be a major concern. Excessive bleeding may result when the contractions of the uterus after delivery are impaired, and the blood vessels that opened when the placenta detached from the wall of the uterus continue to bleed. It can also result from other causes such as cervical or vaginal lacerations.
Post-Term Pregnancy and Post-Maturity
In most pregnancies that go a little beyond 41 to 42 weeks, called late-term pregnancy, there are usually no problems. But problems may develop if the placenta can no longer provide enough nourishment to maintain a healthy environment for the baby. The risks can become significant in post-term pregnancies, those that go to 42 weeks or more.