(Postdate Pregnancy; Postdates; and Prolonged Pregnancy)
A typical pregnancy lasts between 38 to 42 weeks. A postterm pregnancy lasts beyond the 42 weeks. The risk for certain health problems is higher in post-term pregnancies than in full-term pregnancies. This condition requires additional care and monitoring from your doctor.
The exact cause of a prolonged pregnancy is unknown. About 5% to 10% of pregnancies are post-term.
A risk factor is something that increases your chance of getting a disease or condition. Tell your doctor if you have had a prior postdate pregnancy. You may be more likely to have one again.
Your doctor will ask about your symptoms and medical history, and perform a physical exam.
To assess the baby’s health, your doctor may use a machine (an electronic fetal monitor) to check the baby’s heartbeat. She may also conduct an ultrasound]]> . An ultrasound is a test that uses sound waves to examine the baby. It will measure the amount of amniotic fluid around the baby and see how much the baby is moving.
To see if your body is preparing for labor, your doctor may also check your cervix to see if it is opening and thinning.
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Some women and their doctors choose to wait for labor to begin on its own. During this “wait and see” period, the physician will closely monitor the baby’s heart rate, amniotic fluid levels, breathing, and movement. If there are any signs of problems, or your pregnancy continues beyond two weeks after the due date (42 weeks of pregnancy), your doctor may recommend labor induction.
If labor has not started naturally, there are a number of ways your doctor can try to trigger or “induce” labor.
- Medicine can help the cervix open and soften (could be a pill, gel, or suppository)
- A small tear is made in your amniotic sac to “break your water” (this is painless and can triggers contractions)
- Your doctor may perform a membrane sweep, in which she uses her finger to "sweep" around the neck of your cervix to separate it from the membranes around your baby. This action releases hormones called prostaglandins, which may induce labor. A recent study showed that a membrane sweep reduced the rate of post-term pregnancy when performed on pregnant women at 41 weeks of pregnancy. *]]>
- Your doctor may give you a medicine ( ]]>oxytocin]]> ) through a vein in your arm or hand (intravenously) that will start your contractions and help them to remain strong and regular.
Full Term Fetus with Membrane
There is little that can be done in advance to reduce your chances of having a post-term pregnancy. If your pregnancy lasts beyond 42 weeks, talk to your doctor before trying any home remedies for starting labor. Most home remedies are unproven and some may be harmful to you or your baby.
The American College of Obstetricians and Gynecologists
American Academy of Family Physicians
The Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada
Briscoe D, Nguyen H, Mencer M, et al. Management of pregnancy beyond 40 weeks’ gestation. Am Fam Physician . 2005;71:1935-1941.
Inducing labor: your questions answered. MayoClinic.com website. Available at http://www.mayoclinic.com/invoke.cfm?ID=PR00117 . Accessed August 10, 2005.
Labor induction. American Academy of Family Physicians website. Available at: http://familydoctor.org/450.xml . Accessed August 10, 2005.
Overdue pregnancy: what to do when baby’s overdue. MayoClinic.com website. Available at: http://www.mayoclinic.com/invoke.cfm?ID=PR00116 . Accessed August 2, 2005.
Post-term pregnancy: what you should know. American Academy of Family Physicians website. Available at: http://www.aafp.org/afp/20050515/1942ph.html . Accessed August 15, 2005.
Pregnancy: what to expect when your due date has passed. American Academy of Family Physicians website. Available at: http://familydoctor.org/143.xml . Accessed August 10, 2005.
Sanchez-Ramos L, Olivier F, Delke I, et al. Labor induction versus expectant management for post-term pregnancies: a systematic review with meta-analysis. Obstet Gynecol . 2003;101(6):1312-1318.
*Updated section on Treatment on 7/19/06 according to the following study, as cited by DynaMed's Systematic Literature Surveillance : de Miranda E, van der Bom JG, Bonsel GJ, et al. Membrane sweeping and prevention of post-term pregnancy in low-risk pregnancies: a randomised controlled trial. BJOG . 2006 Apr;113(4):402-8. ]]>
Last reviewed November 2008 by Jeff Andrews, MD, FRCSC, FACOG]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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