Definition
A normal pregnancy lasts 38 to 42 weeks. A post-term pregnancy lasts longer than 42 weeks. This raises the risk of certain health problems. Proper prenatal care can improve outcomes.
Causes
The most common cause is an incorrect due date. In other people, the exact cause is not known. Changes in hormone levels or certain defects with the baby may play a role.
Risk Factors
Things that may raise the risk are:
- Prior post-term pregnancy
- First pregnancy
- Older age of the mother
- Obesity
- Having a boy
Diagnosis
The doctor will review your history to make sure the due date is right. You may need:
- A pelvic exam to check the cervix for signs that labor may be near
- An ultrasound to see how much fluid is around the baby, what position the baby is in, or to check on your baby's movements
- Fetal monitoring to check baby's heartbeat
Treatment
The goal of treatment is for labor to begin. Options are:
Close Monitoring
Some women and their healthcare providers choose to wait for labor to begin on its own. During this time, the doctor will watch the baby’s heart rate, fluid levels around the baby, and the baby's breathing and movements.
The doctor may start labor if there are any problems or the pregnancy lasts longer than 42 weeks.
Starting Labor
If labor has not started on its own, there are ways the doctor can start it. These include:
- Medicines to help soften and open the cervix.
- Breaking the water by making a small tear in the sac around the baby
- Separating the membranes around the baby by running a finger around the neck of the cervix
- Giving a medicine called oxytocin to start contractions
Starting labor rather than waiting lessens the chance of needing a cesarean section.
Full Term Fetus with Intact Membranes |
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RESOURCES
The American College of Obstetricians and Gynecologists https://www.acog.org
Office on Women's Health https://www.womenshealth.gov
CANADIAN RESOURCES
The Society of Obstetricians and Gynaecologists of Canada https://www.sogc.org
Women's Health Matters—Women's College Hospital http://www.womenshealthmatters.ca
References
Labor induction. EBSCO DynaMed website. Available at: https://www.dynamed.com/management/labor-induction. Accessed September 15, 2021.
Labor induction. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/labor-induction. Accessed September 15, 2021.
Postterm pregnancy. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/postterm-pregnancy. Accessed September 15, 2021.
Pregnancy: What to expect when you're past your due date. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/pregnancy-expect-youre-past-due-date. Accessed September 15, 2021.
Revision Information
- Reviewer: EBSCO Medical Review Board Mary-Beth Seymour, RN
- Review Date: 07/2021
- Update Date: 09/15/2021