This little organ (at birth it weighs about a pound) also helps to protect your baby from infections and potentially harmful substances. Unfortunately, it is not a foolproof filter; it can't always distinguish good substances from bad. That's why pregnant women are advised to steer clear of substances that can cause harm to their baby like alcohol, drugs, cigarette smoke and herbal supplements.
The placenta forms from the same cells as your baby does. It attaches to the wall of the uterus. The baby's umbilical cord forms on the side of the placenta nearest the baby.
In most pregnant women, the placenta forms and grows just as it should. In some cases, however, the placenta does not grow properly, it is poorly positioned in the uterus, or it does not function properly. It may be too thick or too thin, have an extra lobe, or connect abnormally to the umbilical cord or fetal membranes. Infections and blood clots can also damage the placenta. Placental problems are among the most common complications reported in the second half of pregnancy. The most common placental complications are: placental abruption, placenta previa and placenta accreta.
After the baby is born, the placenta's job is done and it is usually delivered a few minutes after the baby. Your health care provider will examine the placenta after delivery to make sure it is complete and that no parts remain inside your body. If your baby has certain complications, such as slow growth or an infection, the placenta may be sent to a laboratory for further analysis, to help identify the cause of the problem.
September 2005
