Women's Healthcare Topics

40 Weeks Pregnant

Reviewed by James Brann, M.D.

When should You Head to the Hospital?
Before 40 weeks pregnant, your doctor should have already talked to you about when to head to the hospital or birthing center.

Some doctors may prefer for you to come sooner than later, depending on your individual situation. Women who have high-risk pregnancies may be asked to come at the first sign of labor, whereas others with low-risk pregnancies might be asked to come after contractions have been regular for an hour or more.

If your water breaks, regardless of whether you're having any other signs of labor, you need to go to the hospital right away. This is a sign that labor is imminent.

Talking to Your Doctor about Labor Induction
After pregnancy week 40, you may be advised to undergo a labor induction. Labor induction is commonly used when your labor doesn't start on its own, and your doctor is worried about the risks of a prolonged pregnancy. After pregnancy week 42, the placenta becomes less effective at delivering nutrients to your little baby, and this can cause all kinds of complications.

In some cses, you may opt for a planned labor induction. Women plan to induce labor for a number of reasons, including convenience (such as being able to control when your baby will come into the world) and medical reasons (continuing the pregnancy is not recommended). In the United States, over 20 percent of all pregnancies are induced. Because labor induction can increase your likelihood of delivering a premature baby (due to the possibility of your estimated due date being inaccurate), most doctors do not recommend labor induction before 38 weeks pregnant.

Methods of Labor Induction
To induce your labor, your doctor may perform one of the following methods:

Stripping the Membranes - Your doctor places his or her gloved fingers just inside your cervix and sweeps the amniotic membranes (the thin membranes that connect the wall of the uterus to the amniotic sac). The purpose of stripping the membranes is to cause your body to produce prostaglandins, which help soften your cervix and start labor.

When your doctor stripes the membranes, you may experience intense cramping and some bleeding (or spotting). This procedure may feel uncomfortable, and it is only performed in term pregnancies.

Ripening or Dilating the Cervix - If your cervix is not quite ready for delivery, your doctor can induce labor by using certain medications or devices that will soften your cervix and help it dilate for labor. You may be given synthetic prostaglandins to help begin labor, either by mouth or inserted into the vagina.

Rupturing the Amniotic Sac - Your doctor may artificially break your water to induce labor. During this procedure, called an "amniotomy," your doctor uses a thin plastic hook to rupture, or break, your amniotic sac. This is performed for term pregnancies and only if your cervix is partially dilated and your baby's head has moved down into your pelvis.

In many cases, you will go into labor within a few hours of your water breaking. However, every woman's labor is different. Another method of labor induction may be performed, in addition to an amniotomy, if your labor does not occur.

Oxytocin or Pitocin - Your doctor may use oxytocin (Pitocin), which is a synthetic hormone that causes contractions. Oxytocin may be used to induce labor, or to make your contractions stronger.

Giving Birth Section

Signs of Labor

If you haven't already, review the signs of labor so that you can recognize them when the time comes. Signs of labor include lightening (baby drops into the pelvis), a loss of your mucous plus (also called a bloody show), your water breaks (rupture of membranes), and labor contractions that come at regular intervals and get progressively stronger and closer together.

Lightening (baby "drops" into the pelvis) - You should have felt your baby descend into your pelvis a few weeks ago. By now, your bump should be lower in your abdomen, and you have probably felt increasing discomfort in your pelvic area. (You're probably waddling too.)

Diarrhea and flu-like symptoms - In the hours prior to the onset of labor, you can experience frequent bowel movements and diarrhea. You may also start to get nauseous and even vomit. It may feel like you're battling morning sickness all over again.

Cervix effacement and dilation might be taking place without your knowledge. In late pregnancy, Braxton Hicks contractions can begin to thin out and open your cervix just a little bit. As you enter labor, your cervix will continue to dilate and efface. When your baby is ready to be born, your cervix will have dilated to 10 centimeters!

Your water breaks - If your bag of water breaks, you should be having regular contractions. Some women don't have any contractions until after their water breaks. This is a sign that your baby is ready to come out into the world. When your water breaks, it can be a gush of fluid - just like a dramatization that you'd see on TV. However, you may also feel a trickle of fluid from your vagina.

Braxton Hicks contractions will become more intense now. There's a good chance that these practice contractions will turn into real labor pains this week. If your contractions aren't going away, regardless of whether you take a short rest or walk around, you're having real contractions! At this final week in your pregnancy, it's a good idea to start timing your contractions.

Contractions - When you're in labor, you will start to feel true contractions. Unlike Braxton Hicks contractions, you are going to feel contractions that get stronger, occur closer together, and last longer. At first, they may be 10 or 20 minutes apart. As labor progresses, they are going to start hitting you every 3 to 4 minutes. It's a good idea to head to the hospital when your contractions are coming every five minutes for at least one hour.

Pelvic pressure is probably causing you a lot of discomfort. Most babies are in the head-down position by now, so don't be surprised if your little one's head decides to bump against your bladder and hips. Fortunately, this pelvic pressure will go away once your baby is born.

Difficulty sleeping is an understatement. Your huge belly makes it uncomfortable to even side sleep these days. Some women find that the only place to rest is a comfy recliner. Although it may be tempting to take some herbs or sleep aids, resist the temptation. You won't have to suffer through this symptom for much longer.

Post-Term Pregnancy

A post-term pregnancy, or a pregnancy that lasts longer than 42 weeks, increases your baby's risk of being a stillbirth (baby with no heartbeat), being overly large, and experiencing fetal distress. If you have a post-term pregnancy, you're at increased risk of having a difficult labor and delivery and you may face a complicated C-section.

Although you're anxious for baby to come at 40 weeks pregnant, try not to worry about having a post-term pregnancy. They only occur in 10 percent of all pregnancies. Most babies are born between pregnancy week 37 and 42. So try to relax during this last week of your pregnancy.

Get as much rest as you can. You are going to need it during labor and delivery and in the first months after your baby's born.

Natural Labor Induction

Are you thinking about ways to induce your labor naturally? If you are, you should take great care to make sure that you don't try to do anything that might be harmful to your baby.

There are a number of natural “labor inducers” that will stimulate labor contractions and start labor. Some women will swear by these methods, whereas others simply had fun trying. Here is a list of the more common natural labor inducers women have been trying since the dawn of time:

  • Make Love With Your Partner This week - Not only will this help the two of you feel closer, but it may just start your labor. Sexual intercourse is a natural labor inducer, after all.

  • Walking - Walking is great exercise. It can help stimulate labor particularly if you are having contractions that aren't yet regular. Walking can help your baby move further down into the birth canal for delivery. Most women find walking also helps relieve some of the discomfort associated with contractions.

  • Spicy Foods - Some people believe that spicy foods or foods that contain cumin and garlic help trigger labor. While there is no specific 'science' behind this idea, there is nothing wrong with trying.

  • Nipple Stimulation - Nipple stimulation can be a very powerful way of inducing labor. Nipple stimulation causes the body to release oxytocin, which like pitocin (a synthetic substance used to induce labor contractions) can cause uterine contractions. Nipple stimulation can lead to very long and very strong uterine contractions. This can be dangerous for your baby because the long contraction can cause your baby's heart rate to slow. You should only perform nipple stimulation if you have your doctor’s approval and even then you should monitor your contractions slowly to be sure you don't over stimulate. Generally you should ease off nipple stimulation during each contraction to help minimize a prolonged contraction.

  • Castor Oil - You should not try inducing labor with castor oil unless you talk with your doctor first. Many midwives suggest that women who are past their due dates consider using castor oil. It may trigger spasms in the colon and intestines, which surround the uterus. These can result in labor contractions. Castor oil is foul smelling and generally tastes very bad. It will cause horrible diarrhea in most women. If you are considering this, be sure to talk with your doctor first to see what dose they might recommend, or what other methods they might suggest.

  • Membrane stripping - In some cases, your doctor may strip your membranes. This can sometimes help start labor. During a vaginal examination your doctor will place a finger through the cervix and basically 'sweep' the membranes. This helps release the amniotic membranes from the lower uterine cavity. Sweeping of the membranes may release prostaglandins, which can help start contractions.

  • Primrose oil - There is also some evidence that supplementation with evening primrose oil may help soften the cervix and prepare your body for delivery. You should be able to find evening primrose oil supplements at your pharmacy. Ask your healthcare provider about dosing.

Most natural labor induction methods will only work if your cervix is ripe and you are ready to go into labor anyway. You should never try to induce labor before you are 40 weeks pregnant to ensure that your baby is ready.