Identifying the optimal gestational age with minimal complications for mother and baby has been a topic of long-standing interest.
Advances in technology and access to care over the past few decades have led to a remarkable evolution in determining gestational age and identifying optimal time for delivery. Identifying the optimal gestational age with minimal complications for mother and baby has been a topic of long-standing interest.
FIGURE 1. US Deliveries by Gestational Age Categories6
The American College of Obstetricians and Gynecologists has long recommended a minimum of 39 weeks unless a maternal or fetal complication exists to recommend earlier delivery, with specific guidance available for those optimally delivered in the late preterm and early-term periods. Tita et al determined that even in the time period identified as “term”
(> 37 weeks), there are risks to delivering before 39 weeks.1 This led to redefining epochs of gestational age, including that of “early term” to define the 37th and 38th weeks of gestation.2
Importantly, the advent of ultrasound, especially first-trimester ultrasound to optimize dating, has had major implications on gestational-age dating and, hence, timing of delivery. It was anticipated with the advent of ultrasound, especially in the first trimester, that postdates pregnancy would cease. Ultrasound has enabled further-nuanced timing of delivery, even within a 1- to 2-week time frame in the setting of maternal, fetal, or obstetrical conditions.3,4
FIGURE 2. Percent of Total US Births by Gestational Age6
By 2013, women had an average of 4 to 5 ultrasounds in pregnancy, with at least half receiving a targeted ultrasound. In addition, in 2013, the definitions of late preterm (34w0d-36w6d), early term (37w0d-38w6d), full term (39w0d-41w6d), late term (41w0d41w6d), and post term (> 42w0d) were clarified and cemented into the literature.5 Thus, by this time, the dating of pregnancy was more commonly by—or at least incorporating—ultrasound. As seen in Figure 1, this resulted in a greater percentage of full-term deliveries and fewer early-term and late-preterm deliveries in 2016.6 Furthermore, the number of late-term and postterm deliveries has continued to decline.6
Interestingly, with these changes and the improved dating utilizing ultrasound, the timing of delivery has increased the number of deliveries at 39 weeks of gestation (Figure 2),6 which is likely predominantly due—given that the greatest increase is after 2007—to enhanced use of ultrasound rather than new definitions of terminology or trials demonstrating improved outcomes with induction in specific populations at 39 weeks.7
With enhanced access to early ultrasound and optimized pregnancy dating, situations that benefit from early delivery will improve outcomes for providers, patients, and families. Although so many obstetric practices have stood the test of time, innovation on the foundation of obstetrics—identifying gestational age—has made a major impact on our field.
References:
Disparities in kidney care access for pregnant patients
December 11th 2023A recent study highlights significant disparities in kidney transplant and nephrology care access for pregnant patients with end-stage kidney disease, revealing reduced survival rates and limited access to crucial care compared to non-pregnancy-related causes.
Read More
S4E1: New RNA platform can predict pregnancy complications
February 11th 2022In this episode of Pap Talk, Contemporary OB/GYN® sat down with Maneesh Jain, CEO of Mirvie, and Michal Elovitz, MD, chief medical advisor at Mirvie, a new RNA platform that is able to predict pregnancy complications by revealing the biology of each pregnancy. They discussed recently published data regarding the platform's ability to predict preeclampsia and preterm birth.
Listen
Mediterranean diet linked to improved pregnancy outcomes
December 8th 2023A comprehensive meta-analysis scrutinizes the Mediterranean diet's impact on female reproductive health, uncovering compelling evidence that links this nutritional approach to a significant reduction in adverse pregnancy outcomes.
Read More
Mosie Baby Kit receives class 2 FDA clearance for intravaginal insemination
December 6th 2023Discover how Mosie Baby's at-home insemination kit, the first FDA-cleared of its kind, empowers individuals facing infertility challenges with an effective, easy-to-use solution for intravaginal insemination.
Read More
Link between infertility and autism spectrum disorder risk
December 6th 2023New research uncovers a connection between infertility and autism spectrum disorder risk, prompting a closer look at perinatal influences and the potential impact of fertility treatments on the developmental trajectory of children.
Read More