Though the pregnancy is said to be for 9 months, doctors measure the pregnancy in terms of days and weeks.
The normal pregnancy duration is nearly 37 weeks to 42 weeks, with the expected delivery date at 280 days or 40 weeks from the very first day of the last menstrual cycle.
The pregnancy beyond 42 weeks is called as the prolonged pregnancy or post term pregnancy.
Pregnancy that prolongs above 42 weeks is accompanied with some risks to the mother and the baby.
Here are the risks to the baby are mentioned.
Neonatal death or stillbirth
The occurrence of baby death or stillbirth is increased if the pregnancy continues beyond 42 weeks. But the risk is nearly small, only about four to seven deaths occur in thousand deliveries.
Large size of the body
The post term fetuses will have a good chance of developing the difficulties related to the large size of the body which is called as macrosomia. Difficulties can consist of the prolonged labor, birth trauma related to the problem in delivering the shoulders, and complication in moving through the vagina.
Dysmaturity of the fetus
It is also known as the postmaturity syndrome, which is referred to the fetus whose development after the expected delivery date has been limited in the uterus, usually because of the difficulty with the delivery of the blood to the fetus via placenta.
If there is a stress in the fetus, there will be a chance of swallowing the amniotic fluid containing meconium. This can result in the breathing problems when the babyâ€™s birth takes place.
Risks which may faced by the mother
Mother may face some risk factors related to the postterm babies larger size, and also can have complications during labor, injury increase to the perineum ( containing labia, rectum, and vagina), increased cesarean birth rate with its associated bleeding risks, infection, and also injury to the surrounding organs.
In most of the cases, a miscalculated expected delivery date is mainly responsible for considering the pregnancy as postterm.
Miscalculation of the due date
If the pregnancy advances beyond 41 weeks or 42 weeks, your doctor will first find out the accuracy of the due date. Going back to the previous tests and exams will help the doctor in finding out the length of pregnancy. Knowing about when you felt the first baby movement, when the first heart sounds of the fetus were heard, how well the babyâ€™s size correlated with the pregnancy date, uterus height at 20 weeks, and the early ultrasound test results all will give the measures of the gestation length at various points at the time of pregnancy.
If your general practitioner finds that your pregnancy is really postterm, the doctorâ€™s approach will depend upon the individual conditions. Tests to know the fetal condition will give useful information. If there is an indication that the condition of the baby may be worsening, or there is a low volume of amniotic fluid, then they will take the decision to deliver the baby.