One of the most common questions a pregnant woman is asked after announcing she has a baby on the way is “When are you due?” And the askers are not often looking for a roundabout answer. They want a specific date—time, too, if you don’t mind. It’s no wonder then that moms-to-be start to hang their hopes on that red-pen-circled block on the calendar with visions of a birthday dancing in their heads. But sometimes baby has a different plan. Here’s the lowdown on the “plus” side of your 40-plus week gestation.
Pinning it down
First order of business for your doctor at your inaugural OB visit: Assign a due date. A due date is calculated to be 40 weeks from the first day of your last menstrual period. But just how sure are they about that potentially fateful day? Myra J. Wick, MD, PhD, OB/GYN and medical editor-in-chief of Mayo Clinic Guide to a Healthy Pregnancy, explains the process for nailing down a delivery day estimate: “The ‘due date’ is traditionally based on the last menstrual period. [But] this is accurate only in women with regular normal menstrual cycles. In women who have irregular periods or are unsure of dates, ultrasound is used.”
However, even ultrasounds have a variation in accuracy, depending on how far along the mom is when the ultrasound is performed. Wick reports, “Overall in the U.S., 6 percent of pregnancies are postterm, which is defined as a pregnancy that extends to or beyond 42 weeks. However, in pregnancies dated by first trimester ultrasound, only 2 percent of these pregnancies become postterm pregnancies. Thus, most ‘postterm pregnancies’ result from inaccurate last menstrual period dating.”
Once you have your date stamp, just how much stock should you put in it? Not a whole lot, says Nancy Lantz, RN, BSN, ICCE, CD, president-elect of the International Childbirth Educators Association. “Less than 5 percent of babies are born on their given due date. By definition [a due date] is only an estimate. Both the World Health Organization and the American Congress of Obstetricians and Gynecologists consider a baby to be ‘at term’ between 37 and 42 weeks of gestation.” That’s a fairly wide margin on either side, so cut your body some slack if you find yourself still heavy with child on a postdelivery date. Baby may just not be ready yet, and that’s perfectly normal.
A time for action
When doctors suggest medical intervention to get things going, it’s usually for good reason. At your 40-week checkup, and perhaps a week or so before, your caregiver may begin to discuss testing of the baby to ensure he or she is still at optimal health levels to remain in utero. Says Wick, “Antenatal surveillance (checking fetal well-being) is recommended for postterm pregnancies. This can be accomplished with a nonstress test combined with amniotic fluid volume, a biophysical profile, or a contraction stress test.” Lantz adds that your doctor will be particularly interested to see that the baby is still growing, that your fluid levels are holding steady, and that the placenta is still doing its job. “The placenta can age and get calcifications in utero that can disturb the flow of oxygen and nutrition to the baby,” she adds. If your doctor finds anything concerning, it’s likely she’ll begin to discuss induction options.
Staying the course
In addition to being physically uncomfortable, women who find themselves on the other side of their due date with no baby to show for it often struggle emotionally. Playing the waiting game for even a day longer than you expect is taxing for any mom-to-be. But Lantz advises mothers to take a pause and assess how things really are before asking for unnecessary induction. “I try to see where they are emotionally with it. I ask them what their concerns are. Is your baby still kicking? How’s the amniotic fluid? Have you had a nonstress test? Make the decision that’s best for you. I work with moms to trust their bodies. Your baby’s brain is still developing … [so ask yourself] ‘What can you do for you today?’ Go to the spa, whatever it takes to get you through the day.”
After all, even though those last few days or weeks may seem longer than all of the nine preceding months, your baby will come. Remember to focus on the carrot on the end of the stick, and you’ll be cradling your sweet babe in no time.