A typical pregnancy ends in labor between the 38th and 42nd week, according to FamilyDoctor.org. Any pregnancy that goes beyond 42 weeks is considered a post-term pregnancy. There are many reasons why a pregnancy goes beyond the typical due date. It is possible that the due date was miscalculated. Ultrasounds are often done throughout the pregnancy, but they can be unreliable in estimating the size of the baby and the progress of the pregnancy. As with any pregnancy, there may be complications when labor has not started well beyond the due date.
Amniotic Fluid
One of the possible risks of a post-term pregnancy is insufficient amniotic fluid, called oligohydramnios. As the baby gets bigger the fluid may start to leak or may not be enough to protect the baby. An ultrasound can reveal this complication. The American Pregnancy Association points out that decreased amniotic fluid can reduce the functioning of the placenta, which is what provides the baby blood and nutrients during pregnancy. Without this, the baby may die in the womb. Keeping a close eye on the baby with fetal non-stress test can identify potential problems. The test monitors the baby's heartbeat and movement.
Cephalopelvic Disproportion
The longer baby stays in the womb, the bigger she is likely to get. While there is the potential for the baby to be too large to fit through a woman's pelvis, called cephalopelvic disproportion, the American Pregnancy Association points out that an accurate diagnosis of this condition is difficult to achieve. Few women have true CPD and even those who have been diagnosed with it still have a reasonable chance of delivering the baby vaginally. Many birthing facilities and medical professionals do not want to take the risk of the baby not being able to come through the pelvis and may order a Caesarean delivery.
Meconium
The Mayo Clinic points out that as the baby continues to mature, the risk of swallowing fecal waste, or meconium, is greater. This can cause breathing problems or an infection after birth.
Medical Intervention
Depending on the woman's facility and medical professional, a medical induction may be standard procedure after the 41st week of pregnancy. A medical induction can include several techniques. FamilyDoctor.org suggests the doctor may rupture the membranes, also called breaking the water. Women can also be given a vaginal suppository over night of a cervix softening synthetic hormone resembling a prostaglandin. The purpose of this type of drug is to help soften the cervix and encourage dilation. Oxytocin may also be given before or after other medical interventions to trigger contractions. This drug can help soften and dilate the cervix by forcing the baby down in a repeated pattern, just as it would occur in natural labor. This can increase fetal distress and often requires the attachment of fetal monitors. When an induction fails, a cesarean section is the next step in delivering the baby.
