40 Weeks Pregnant and Beyond: What to Do When You're Overdue
Ask any mom whose pregnancy went into extra innings: Right around your due date, the phone calls, emails, and texts start coming: "Is anything happening?" "What does the doctor say?" Playing the waiting game during the last few weeks of pregnancy is hard, but it becomes especially difficult when 40 weeks turn into 41 or 42. But the first thing to know is this: Your due date is just an estimate. In fact, only 5 percent of babies are born on their due date.
"No woman should feel nervous or anxious if she's still pregnant past her due date," says Alex C. Vidaeff, M.D., M.P.H., a maternal-fetal medicine researcher and practitioner at the University of Texas Medical School at Houston. Due dates are tricky because it's hard to pinpoint the exact age of a fetus. Reasons for this include irregular periods (since due dates are calculated based on a perfect 28-day cycle), sketchy or inaccurate menstrual history presented to the obstetrician, and mistaking spotting during very early pregnancy for a period. Doctors usually use several methods together to make their best estimate of a due date, including:
- Calculation based on your last ovulation (the most reliable method).
- Calculation based on the first day of your last menstrual period.
- Clinical examination of the uterus for size.
- Your first detection of fetal movement (the fetus usually makes its first movements between 16 and 20 weeks).
- Fetal heartbeat (in normal pregnancies, the doctor can detect it between 18 and 20 weeks).
- Ultrasound, which during early pregnancy can estimate fetal age within seven to 10 days (it's not as effective later in the pregnancy).
Even so, the reality is that 80 percent of babies arrive between 38 and 42 weeks of pregnancy, so your due date window is much bigger than you might think. "You might really be 39 weeks when you think you're at 40," says Vidaeff, adding that pregnancy length is, in many cases, genetically determined.
- RELATED: Due Date Calculator
The Risks of Going Past Due Date
Only about 1 out of every 10 babies is officially overdue, which means that the baby is born after 42 weeks of pregnancy. Recent research has shown that delivery after 40 weeks may come with certain risks, and OB-GYNs have responded. "We now change our clinical practices at 40 weeks to prevent potential complications in both mom and baby," says Carri R. Warshak, M.D., an assistant professor in the department of maternal-fetal medicine at the University of Cincinnati.
While they're rare, the risks of having an overdue baby include::
- The placenta's ability to provide baby with adequate oxygen and nutrients may be compromised.
- The volume of essential amniotic fluid may decline as baby grows (this increases the possibility of a pinched umbilical cord).
- The possibility of fetal distress increases.
- The baby could grow too large to pass safely through the birth canal (also known as macrosomia).
At the 40-week mark, your doctor or midwife will become more vigilant about monitoring the overdue baby. "Expect twice-a-week visits if you go past 40 weeks," says Sheryl A. Ross, M.D., an OB-GYN in private practice in Santa Monica, California. Methods that your physician can use to monitor your post-term baby's condition are:
- Kick count: A "kick count" is a record you keep of how often your baby moves. Your doctor will tell you to contact him immediately should you notice your baby suddenly decreases his movements. This could be a sign of fetal distress, which would require immediate testing to determine your baby's condition to asses whether delivery should be initiated quickly.
- Nonstress test: This test, a type of electronic fetal monitoring, uses a special instrument to measure how your baby's heart reacts when his body moves. This helps the doctor determine if your baby is in distress.
- Contraction stress test: When your uterus contracts, this test (which is another form of electronic fetal monitoring) measures your baby's heart rate with a special instrument. It helps determine your baby's condition during labor, and allows your doctor to see if there's any fetal distress.
- Ultrasound: Your doctor can determine your baby's size, position, breathing rate, heartbeat, and body movements with an ultrasound. Ultrasound is also useful in determining how much amniotic fluid surrounds your baby. This is important to determine because insufficient amniotic fluid for prolonged periods can cause labor complications. In addition, your doctor can assess the size and position of the placenta using ultrasound. This information is important for your doctor to know because the placenta provides your baby with life-sustaining oxygen. Plus, "if the fetus weighs more than 8 pounds, 13 ounces, you may have difficulty pushing during labor, and using a forceps or vacuum may be necessary for delivery," says Warshak.
40 Weeks Pregnant With No Signs of Labor
After 39 or 40 weeks, it's sometimes best to deliver sooner rather than later: Studies have shown that newborn admissions to the neonatal intensive care unit (NICU) increase slightly when a pregnancy lasts 40 to 42 weeks. And stillbirth, though still rare, becomes a concern: At 40 weeks, the risk is 2 to 3 per 1,000 babies; at 42 weeks, it's 4 to 7 per 1,000. If labor hasn't started spontaneously, you'll probably be induced at 41 weeks—at the latest. "If your cervix has started to dilate, odds are in your favor for a successful induction," Warshak says. Translation: You won't end up having a Cesarean section.
Whether or not you'll be induced depends on your own health, the status of your cervix, and the baby's well-being as determined by a non-invasive procedure called fetal non-stress testing. The conditions inside your uterus past due date may also stress the baby during labor and vaginal delivery. As a result, Warshak says, "Even if your cervix is at 8 centimeters and labor is progressing, we'll do a C-section if the overdue baby is not tolerating labor well."
The Midwife Philosophy
Midwives tend to wait a little longer for induction than OB-GYNs do. "In our practice, we wait until 42 weeks for women to go into labor naturally," says Joanne Hasman, C.N.M., a certified nurse-midwife at Special Beginnings Birth and Women's Center in Arnold, Md. "If they don't by then, we schedule an induction at our hospital. We also try natural methods and refer women for acupuncture, reflexology, or reiki."
At 40 to 41 weeks, if your cervix is dilated at least 2 centimeters, the midwives in Hasman's practice perform what's called a "cervical sweep," using a finger to separate the cervix from the amniotic sac. This can sometimes kick-start labor. "If the woman is really ready [to go into labor], I'll see her back here in 24 to 36 hours," Hasman says.
The C-Section Question
An ongoing concern has been whether induction, as opposed to what's known as expectant management (waiting for labor to start spontaneously while monitoring the mother's and baby's well-being), might lead to a higher risk for emergency Cesarean section, and studies have been conflicting. But a new Danish study of more than 230,000 women found that inducing labor from week 39 to week 41 is not connected with higher C-section rates compared with waiting for labor to begin spontaneously or inducing labor later.
Waiting for An Overdue Baby: 6 Things To Do
Backaches, heartburn, hemorrhoids—at 40 weeks all you want to do is hold your baby in your arms. Here are a few tips to help you cope:
Get a massage. Some Eastern healers believe that certain pressure points on the hands and feet may stimulate the body's natural labor process, although Dr. Ross says this hasn't been proven. Even if you can't get your tired bod to a prenatal massage therapist, asking your partner to give you a rubdown might help your aching back, not to mention your mood.
Become a spice girl. Sadly, there's no magic meal that's guaranteed to bring on labor (although there's that famous maternity salad dressing that some moms swear by). Still, Dr. Ross has had several clients report that things, ahem, got moving after they indulged in a spicy meal. Spicy foods fall into that "can't hurt, might help" category, and we say that once you're more than 40 weeks pregnant with no signs of labor, you've earned the right to eat your baby's weight in Mexican food.
Have an orgasm or two. Remember what we said about distraction? The hormone oxytocin surges when you have an orgasm, which can trigger labor in at-term pregnant women. As an added bonus, sperm contains prostaglandins, which can help ripen the cervix. So the more orgasms, the better!
Keep moving. We're not saying that exercising is easy when you're 40 weeks pregnant with a baby overdue, but try to stay active. Although stretching, doing prenatal yoga, or going for a short walk aren't likely to bring on labor, they're all good for you and your baby. (But don't overdo it: If you do go into labor, you don't want to be tuckered out from the get-go!)
Stay off social media. At this point in your pregnancy, it's acceptable (and maybe even advised) to pretty much avoid anyone and everyone, both in the flesh and online, who isn't your medical practitioner or your partner – in other words, anyone who might have the poor judgment to ask if you're still pregnant. Keep family and friends up-to-date with a daily blog entry, such as: "Just visited the doc, who said everything's fine." Record a new voicemail with an upbeat message: "No, baby's not here yet. Thankfully, we're all healthy. Keep checking this message for daily updates!"
Make good use of your time. If your baby is overdue, take advantage of the time to catch up on sleep, finish the nursery, and stock your larder with ready-made meals. Also consider addressing birth announcements and thank-you notes.