An overdue pregnancy can leave you tired and anxious. Find out what might cause an overdue pregnancy and what it can mean for you and your baby.

By Mayo Clinic Staff

Your due date has come and gone — and you're still pregnant. What's going on?

Although your due date might seem to have magical qualities, it's simply a calculated estimate of when your baby will be 40 weeks. Your due date does not estimate when your baby will arrive. It's normal to give birth before or after your due date. In fact, your pregnancy must continue two weeks past your due date to earn the official label of postterm pregnancy.

You might be more likely to have a postterm pregnancy if:

  • This is your first pregnancy
  • You've had a prior overdue pregnancy
  • Your baby is a boy
  • You're obese
  • Your due date was calculated incorrectly, possibly due to confusion over the exact date of the start of your last menstrual period or if your due date was based on a late second- or third-trimester ultrasound.

Rarely, an overdue pregnancy might be related to problems with the placenta or the baby.

Whatever the cause, you're probably tired of being pregnant, not to mention anxious. Rest assured, an overdue pregnancy won't last forever. Labor could begin at any time.

Research shows that when pregnancy extends between 41 weeks and 41 weeks and 6 days (late-term pregnancy) as well as 42 weeks or beyond (postterm pregnancy), your baby might be at increased risk of health problems, including:

  • Being significantly larger than average at birth (fetal macrosomia), which might increase the risk of an operative vaginal delivery, C-section, or getting a shoulder stuck behind your pelvic bone during delivery (shoulder dystocia)
  • Postmaturity syndrome, which is marked by decreased fat beneath the skin, a lack of a greasy coating (vernix caseosa), decreased soft, downy hair (lanugo), and staining of the amniotic fluid, skin and umbilical cord by your baby's first bowel movement (meconium)
  • Low amniotic fluid (oligohydramnios), which can affect your baby's heart rate and compress the umbilical cord during contractions

Late-term and postterm pregnancies can also pose risks, such as delivery complications:

  • Severe vaginal tears
  • Infection
  • Postpartum bleeding

Prenatal care will continue after you pass your due date. During visits, your health care provider will check your baby's size, heart rate, position and ask about your baby's movements.

If you're more than one week past your due date, your health care provider might do fetal heart rate monitoring (nonstress test) and an amniotic fluid volume assessment or a combination of a nonstress test and a fetal ultrasound (biophysical profile). In some cases, labor induction might be recommended. Labor induction is the stimulation of uterine contractions during pregnancy before labor begins on its own to achieve a vaginal birth.

If you and your health care provider choose labor induction, you might be given medication to help your cervix ripen. Your health care provider might dilate your cervix by inserting into it a small tube (catheter) with an inflatable balloon on the end. Filling the balloon with saline and resting it against the inside of the cervix helps ripen the cervix. If your amniotic sac is still intact, your health care provider might break your water by creating an opening with a thin plastic hook.

If necessary, you might also be given medication to kick-start your contractions. A common choice is Pitocin, a synthetic version of oxytocin — a hormone that causes the uterus to contract.

You're in the homestretch! Whether your health care provider suggests a wait-and-see approach or schedules an induction, stay in touch and make sure you know what to do if you think you're in labor. In the meantime, do your best to enjoy the rest of your pregnancy.

July 01, 2017