When Are You Late?
Most of us guess at our due dates. It is based on last menstrual periods with the speculation that you will ovulate mid month. Unless you have perfect ovulation cycles and your baby gestates perfectly on schedule- or you have IUI or IVF , you really may not know exactly when you are due. The earliest ultrasound is usually the best one to determine the age of the baby based on developement. What is considered term pregnancy? ACOG defined this in 2013, http://www.acog.org/
Definition of Term Pregnancy
ABSTRACT: In the past, the period from 3 weeks before until 2 weeks after the estimated date of delivery was considered “term,” with the expectation that neonatal outcomes from deliveries in this interval were uniform and good. Increasingly, however, research has shown that neonatal outcomes, especially respiratory morbidity, vary depending on the timing of delivery within this 5-week gestational age range. To address this lack of uniformity, a work group was convened in late 2012, which recommended that the label “term” be replaced with the designations early term (37 0/7 weeks of gestation through 38 6/7 weeks of gestation), full term (39 0/7 weeks of gestation through 40 6/7 weeks of gestation), late term (41 0/7 weeks of gestation through 41 6/7 weeks of gestation), and postterm (42 0/7 weeks of gestation and beyond) to more accurately describe deliveries occurring at or beyond 37 0/7 weeks of gestation. The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine endorse and encourage the uniform use of the work group’s recommended new gestational age designations by all clinicians, researchers, and public health officials to facilitate data reporting, delivery of quality health care, and clinical research.
In fact, approximately 7% of babies are not delivered by 42 weeks, and when that happens, it is referred to as a “post-term pregnancy. ”
ACOG even has a pamphlet with information titled What to Expect After Your Due Date.
It is stated that the risks of waiting to have your baby once you are postdates are: dysmaturity syndrome- decreased alertness, low birth weight, and increased respiratory distress, the placenta gets older and may not work as well, the fluid gets less and can cause the umbilical cord to become pinched, the chance of the baby becoming too big is increased and the risk of meconium aspiration is increased. They say it may also lead to an increase of a cesarean birth. They suggest checking on the baby’s well being by using two tests, a biophysical and a non stress test.
There is an excellent blog Birth Without Fear that addresses this as well- http://birthwithoutfearblog.com/2011/08/22/what-acog-has-to-say-about-due-dates/
The Cochran Database is considered a location of studies and summaries that are evidenced based. http://summaries.cochrane.org/
Induction of labour in women with normal pregnancies at or beyond term
A normal pregnancy lasts about 40 weeks from the start of the woman’s last menstrual period, but anything from 37 to 42 weeks is considered as being within the normal range. Births before 37 weeks are considered preterm because these babies often have breathing difficulties and other problems as some of their organs are not yet fully matured. Births after 42 weeks seem to carry a slightly increased risk for the baby and are associated with a greater number of deaths. No tests can tell if a baby would be better to be left in the womb or labor induced and the baby be born, so arbitrary time limits have been suggested. This review set out to determine if induction of labor at a prespecified time could reduce the risks for the baby. The review found 22 trials involving over 9000 women given induction of labor at various times from 37 weeks to over 42 weeks’ gestation; some were quite old trials and the quality was variable. The review grouped the trials by a policy of induction at (1) 37 to 39 weeks, (2) 39 to 40 weeks, (3) < 41 weeks, (4) 41 weeks, and (5) > 41 weeks, compared with a policy of waiting to a later date. There were fewer baby deaths when a labor induction policy was implemented. Such deaths were rare with either policy. Significantly fewer babies developed meconium aspiration syndrome and fewer cesarean sections were required in the induction group compared with the expectant management group. Women’s experiences and opinions about these choices have not been adequately evaluated.
I love this statement on the University of Maryland Medical Center site: “The monitoring and tests that are currently available for post-term pregnancies has helped to increase the likelihood of good outcomes.”
So understand the risks. Also understand the idea of guesstimates regarding due dates. But most of all, focus on doing your kick counts and get your biophysical done and your non stress tests done to determine if your baby may need a little encouragement to vacate the womb!