Overdue Pregnancy

Key points

There is a higher chance your baby will have some kind of problem during labour and birth if you are more than 41 weeks pregnant.
When labour doesn’t start naturally and your baby is overdue, your doctor will talk with you about inducing labour.
Most overdue babies are born healthy.

A normal, healthy pregnancy lasts from 37 to 41 weeks. Babies born during this time are called full-term babies. A baby born before the 37th week of pregnancy is called premature or preterm. If your pregnancy lasts past the end of the 41st week, it is called a post-term pregnancy. In other words, the baby is overdue. At the end of 41 weeks, your doctor may talk to you about inducing labour to make sure your baby is born healthy. This is an important decision that you and your doctor will make together.
How will you know if your baby is overdue?

Your doctor will check your due date. It can be hard to get your due date right if:

you were taking birth control pills just before you got pregnant
you cannot remember the dates of your period or menstrual cycle
your periods were not regular 

Sometimes doctors ask you to go for an ultrasound in your first trimester of pregnancy. This is the best time to find out your due date. Even if more ultrasounds are done later, the due date from your first ultrasound stays the same. Ultrasound is painless. It shows you and your doctor pictures of your baby, inside your uterus.
How can being overdue affect your pregnancy?

The placenta can get old. The placenta grows inside your uterus when you’re pregnant. It keeps the baby alive inside your body. If the placenta is getting old, it can slow down or stop your baby from growing. If the placenta is still doing its job, the baby may grow too big. A big baby can make your labour harder and longer.

There is a higher chance your baby will have some kind of problem during labour and birth if you are overdue, that is, if you are more than 41 weeks pregnant. The baby might not get enough oxygen.

Labour may have to be induced. This can make labour harder or longer. Your baby may have to be born by caesarean section, an operation to cut open your uterus and remove the baby.

The baby could get an infection if the liquid from the amniotic sac leaks out. The baby could also get an infection if the amniotic sac breaks open 18 hours or more before labour begins.
What will happen if your baby is overdue?

Many women will be waiting for labour to begin after the end of the 41st week. This is normal. If it happens to you, your doctor will keep a close eye on both you and your baby. This is very important if you have high blood pressure or diabetes. Even if your pregnancy is normal, there are things your doctor will want to do. These are discussed below.
Counting your baby’s movements

You can do this by yourself at home. Your doctor will tell you what to do. The usual ways to do this are:

Count the number of times your baby moves during a specific period of time.
Count how long it takes for your baby to move 10 times.
Write down what you find. 

Inside the uterus, every baby has their own pattern of movement. Your baby may move around more, or less, than other babies. Also, how much your baby moves can change from day to day. If you notice your baby is moving less than usual, talk to your doctor.

For more information, see Kick Counts.
Non-stress testing

This test is done in the hospital. It is painless. A belt is strapped around your belly and a machine listens to the baby’s heart rate when the baby moves inside the uterus. The test may be done once a week or more while you wait for labour to start. The test will tell you and your doctor if your baby is healthy. If your baby is not moving enough, your doctor may decide to do the test again or induce labour. This test is not always 100% correct, however.
Biophysical profile

Your doctor may want you to go for an ultrasound to see if your baby is healthy. If you have the non-stress test AND an ultrasound, your doctor will add up the results of both tests to see how your baby is doing. This is called a biophysical profile. It can help you and your doctor decide what to do next.
Vaginal examination

Your doctor may want to examine your cervix by doing a pelvic or vaginal examination. Your cervix is the opening to your uterus. It gets very soft before labour begins. If your doctor finds that your cervix is getting soft and opening, you and your doctor can talk about inducing labour. This may be the best thing for both you and your baby.
How does labour begin?

These are some signs that labour may be starting:
The mucous plug comes out

Mucous builds up at the opening of your cervix during pregnancy. Doctors call this the mucous plug. When the cervix gets soft and begins to open, the plug comes out. This can happen a few days or even a few weeks before labour starts.
Show

When labour begins, your cervix starts to get soft and open. As it opens, some blood mixed with mucous may come out of your vagina. This is called show.
Rupture of membranes

When the amniotic sac springs a leak or breaks completely, doctors say the membranes have ruptured. Many women say their "waters broke." This can happen hours before labour begins or it may not happen until after labour has started.
Contractions

During labour your uterus will squeeze and then relax. This is called "having contractions." Contractions push the baby down and out of your body. Some women feel their uterus getting hard and some women have a dull backache. Early in labour, contractions may feel like bad cramps during your period.
What if labour doesn’t start?

When labour doesn’t start naturally and your baby is overdue, your doctor will talk with you about inducing labour.
Look on the bright side

Waiting for labour to begin can make you worry. If it is your first baby, you may worry even more. Remember that most overdue babies are born healthy.