The Everyday Miracle
Most of us know by now how conception works. The husband’s sperm meets the wife’s egg. At that very moment God infuses a new, never-before-existing soul into a new body. Within a week or two that blastocyst baby has traveled through one of the woman’s fallopian tubes and becomes embedded in the uterus, an incredible miracle every time. There, he or she will hopefully stay tucked away in the mother’s womb for another nine months or so, growing at phenomenal rates, developing organs, sustained by the mother’s blood. The baby is attached via an umbilical cord from the abdomen to the placenta. That place where the umbilical cord is attached will eventually become a belly button. The placenta, truly an amazing thing and sometimes referred to in the birth world as “the tree of life,” is an entirely new organ that the mother grows in order to feed and nourish her baby. It is firmly attached to the uterus on one side and to the baby via the umbilical cord on the other. It is the only organ that the human body routinely grows from scratch and then discards. For the baby in utero, it functions as almost every major organ at once.
All of this occurs with very little conscious “doing” on the mother’s part. She may be eating well and supplementing with vitamins and doing her best to take care of herself for her baby’s sake, which are all good and helpful, but she doesn’t have to consciously do any of the growing or nourishing of her baby. Her body is giving, nourishing, and growing this baby, while she works and plays, sleeps and eats. We sometimes hear about women who don’t even realize they are pregnant until halfway through or even further along in their pregnancies. Their body grew a baby without their awareness that it was happening. This, of course, does not mean that pregnancy is always successful. We know the heartbreak of miscarriage. Not every baby develops properly — sometimes this is avoidable and sometimes it isn’t. But this doesn’t discount the fact that the baby’s development lies mostly outside of the mother’s conscious will and work.
Where the miraculous meets the natural, a baby develops and grows against all odds and yet outside of any drastic intervention. The same holds true for birth itself. We can cooperate with our body’s good design, work with it, understand what is happening, and have a good provider so that appropriate measures can be taken to help if needed. But it’s truly transformative for a woman to realize that her body already knows how to give birth and the majority of the time would do it just fine without a whole lot of help.
When Are You Actually Due?
Before we discuss the biological interplay of how birth happens, let’s talk about how long a pregnancy truly lasts.
When will that baby finally be ready, anyway? Babies are considered “at term” when they are anywhere from thirty-seven to forty-two weeks. This means, contrary to what your due date suggests, there is actually a full five weeks during which mom could naturally go into labor. Almost all women, when left on their own, will naturally go into labor sometime during those five weeks.
This is why it’s helpful to consider your due date an estimate, and it’s vitally important that it be accurately calculated. Women who practice natural family planning or who at least have an understanding of their cycles and fertility have an advantage in this area. They have a better idea of the signs of ovulation and can better estimate within a day or two when baby was likely conceived.
The standard for dating a pregnancy, even today, is still to go by the start date of your last period and count from there. This means that, according to the dating system most in use, pregnancy begins before the baby was even conceived! So, when a woman talks about being six weeks pregnant, her baby is actually only about four weeks old. And that’s only if she ovulated right on day fourteen of her cycle — which is a big, and often incorrect, assumption. Using the date of your last period to determine your due date assumes that you experienced the “official” twenty-eight-day cycle and ovulated on day fourteen. But how many women have that textbook cycle every month? (It’s worth noting that the same medical system that mocks the “rhythm method” actually uses it when dating pregnancies this way.)
This method of dating, based on gestation of ten lunar months, follows Naegele’s Rule, attributed to a nineteenth-century German doctor. This method calculates the estimated due date by adding one year to the first day of the last menstrual period, subtracting three months, and adding seven days. The result is approximately 280 days (forty weeks) from the start of the last period, and this is how the paper-wheel calculators in your provider’s office or online calculators usually work. It is actually unclear whether Naegele himself used the first day of the period or the last day to calculate the due date, which would change the calculation significantly.56
Clearly, there are many ways in which using the first day of the last menstrual cycle can give a flawed result. An accurate due date can make the difference between going into labor naturally with a simple, complication-free birth and being pressured into an induction (and the risks included) for being “late” because the doctor thinks the pregnancy is further along than it truly is. This can even mean the difference between a healthy baby and a baby sent to the NICU or who has other struggles simply because they were taken out before they were ready.
Many obstetricians nowadays use early ultrasounds to date pregnancy. Using the ultrasounds and measurements of the baby, they can make a fairly accurate estimate of gestational age and when the baby is due. While this method is more accurate in determining the gestational age of a baby than the last menstrual period is, there is still room for error. The most accurate ultrasounds are those done in the first trimester. Many moms, however, are concerned about ultrasounds since, despite widespread and frequent use, their effects have not been sufficiently studied in controlled trials.57 The American College of Obstetricians and Gynecologists has also warned against non-medically indicated ultrasound use,58 stating that it hasn’t been adequately studied and additional side effects could be discovered. Dating a pregnancy can be considered a medical use, and it may be necessary for some women, but, if possible, the most accurate “official” due date comes from knowing within a day or two when the baby was conceived and calculating from there.
What we call the due date is simply the day of the pregnancy counted forward to forty weeks (based on the last menstrual cycle). This is the midpoint of when a healthy woman will typically go into labor. It’s interesting to note that the number forty is used often in Scripture by God to represent the fullness of something. Certainly, this shouldn’t be considered a coincidence! Recent studies have shown that (using the traditional dating) the median date for women going into natural labor with their first baby and an uncomplicated pregnancy is actually forty-one weeks plus one day. For multiparas (mothers who have already given birth), the median was forty weeks plus three days.59
It is important not only to know your true estimated due date, but also to know that the date is not an expiration or “eviction” date, as you may have heard some people say. Nothing dramatic happens on that date, and your baby does not have a calendar in the womb to know when his or her “due date” is. It is important for you to know how far along you actually are, as well as the current standards of care, which do not consider a baby “overdue” until past forty-two weeks.60 New standards have been put into place and encouraged since 2013 based on research that showed when babies at term had the best outcomes. Those new standards broke the five-week span into three groups:
Early term — 37–39 weeks
Full term — 39–41 weeks
Late term — 41–42 weeks
Notice that it is only when a mother goes past that forty-two-week mark that she is considered “overdue” or “post date.”61
Consider your estimated due date just that — an estimate. It might help to think of it and talk about it as a “due time”
