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” or “due month.” The end of pregnancy can be challenging, and it can be discouraging to a mother when she and others have this magical date in mind. Some women don’t even tell others the exact date because of the pressure then felt to have the baby, or to “perform” by that date. If you think others will be overly excited to have the baby born by that date, putting unrealistic or unhealthy pressure on you and the baby, consider telling people “sometime in May” rather than the exact forty-week mark. Remember, the due date is simply the date in the middle of the five-week window when you might have the baby. It is not an expiration date. Special circumstances aside, your baby will come when your baby is ready.
So-o-o, How Does It All Work?
Sometime during those five weeks at term, you will go into labor. When your body goes into labor, you are flooded (usually unbeknownst to you) with hormones that begin the work of opening the uterus wide enough to allow the baby to pass through. We break this down into three observable “stages” of birth:
Labor (First Stage): The womb contracts and gradually opens the cervix (simply the opening of the uterus).
Pushing (Second Stage): The baby is pushed out of the uterus by a different type of contraction.
Afterbirth (Third Stage): The woman’s womb contracts again to release the placenta and begins to shrink back down to its pre-pregnant size.
What Starts Labor?
Interestingly, very little is known about how God designed labor to begin and what actually “triggers” it. We know that most babies do best when they are allowed to gestate until they are ready to come out, and theories have been growing that in a healthy mom it actually is the baby that decides when he or she is ready. Scientists have recently discovered that babies release a protein in their lungs that plays a part in triggering mom’s body to go into labor.62 We know the mother responds to that release with increasing amounts of oxytocin, and that is what stimulates the uterus to begin to contract and open up.
It is amazing that we don’t actually know more about what “flips the switch,” but we do know that God designed labor and birth, so it is wise to be very careful about intervening without sufficient reason. Babies that are brought out too early often have breathing difficulties, struggle with nursing, and are more vulnerable to infection and being sent to the NICU. If a mother’s body isn’t ready, the birth is more likely to have complications and end in a cesarean section. When it is possible and other situations don’t arise, waiting until the baby’s and mom’s bodies are both ready gives the best possible chance for a simple, complication-free birth.
It can take a great amount of trust, especially at the end of a pregnancy, to know that your body will go into labor. Support and encouragement from your husband, like-minded friends, and provider are invaluable at this time. Have a project or two that you leave until those last few weeks, and keep making plans that you can look forward to. I even recommend making plans past the estimated due date, knowing that you can always cancel. Most women find it’s more helpful to have things to do and stay active and positive, rather than clearing the schedule only to sit around waiting for labor to start. Those last few weeks of pregnancy are challenging enough without adding internal pressure and frustration with your body and your baby into the mix.
There are most certainly situations that can arise where it is best to intervene and artificially induce labor for mom or baby. A good provider will be diligent in care but prudent in intervening, doing so only when it is of pressing concern.
Opening the Womb
When labor begins, the body begins to release large amounts of oxytocin into both the bloodstream and the nervous system, and the uterus begins to contract. Oxytocin, known as the “bonding hormone,” or “love hormone,” is released in torrential amounts during three main times: orgasm, labor contractions, and while breastfeeding. It is also released in much smaller amounts through touch, kissing, low lighting, good smells, and good memories. Because it is a neurotransmitter (unlike the synthetic form Pitocin), it affects both our brain chemistry and the rest of our body.
One of the main purposes of this hormone release is to bond two people together, emotionally and chemically, as happens between husband and wife. This tells us something amazing about God’s plan: husbands and wives are designed to be bonded for life, and mothers are designed and biologically created to have a real and lasting bond with their baby. God’s plan of family is written into our very bodies. This is one reason why it hurts so much when a sexual relationship ends, why a mother who never knew her baby past birth can still feel eternally connected to him or her, and why we can feel bonded after birth to the people who were with us during it. Our bodies are meant to work with our souls and are designed to reinforce and work with spiritual reality.
Oxytocin release is encouraged when a mother feels safe, respected, and private. The opposite is also true. If she feels threatened, exposed, judged, or vulnerable, it can inhibit the release of this incredibly important hormone. This means that a woman’s environment (both people and place) matters greatly to the birth process itself. The release of oxytocin begins contractions that are usually subtle at first but continue to grow and intensify. Most women who go into labor naturally have a difficult time pinpointing when exactly labor began. For most, early contractions begin gradually and gently, and are often not all that notable. There is usually not a concrete “this is it” contraction that begins labor, as we often see in the movies. The majority of women do not have their water break before labor begins, also contrary to most television and movie portrayals.