American Journal of Obstetrics and Gynecology
Original ResearchObstetricsEvidence that children born at early term (37-38 6/7 weeks) are at increased risk for diabetes and obesity-related disorders
Introduction
The long-term potentially devastating consequence of prematurity on children’s health is now well established. Rates of long-term neurodevelopmental and medical morbidities are higher among survivors of preterm deliveries compared to children born at term.1, 2, 3, 4 Prematurity has also been recognized as a risk factor for different metabolic and endocrine disorders in childhood and adolescence including hypothyroidism,5, 6 insulin insensitivity,7, 8, 9 and overweight and obesity.10 Since fetal hormonal axis development is a continuum,11, 12 it may not achieve full maturity in preterm neonates, thus influencing endocrine function later in life. In addition, the forced immediate adaptation of the hormonal axes, required for coping with preterm extrauterine life,13 may influence the function of these axes later in life. A third possible explanation for the interrelationship between prematurity and endocrine morbidity is that abnormal fetal endocrine function serves as the initial mechanism responsible for preterm parturition.13, 14
Ten years ago, the Eunice Kennedy Shriver National Institute of Child Health and Human Development changed the term referring to deliveries occurring between 34-36 weeks of gestation from “near term” to “late preterm.”15 This was due to the recognition that morbidity and mortality rates in these newborns were similar to those of preterm ones, as opposed to term newborns. Moreover, research in the past decade has revealed that even within the 5-week span of term gestation (37-42 weeks’ gestation) there appears to be a continuing fetal maturation process16 that is later reflected in short- and long-term morbidity rates of the offspring.17, 18 Indeed, short-term neonatal adverse outcome in early term deliveries (37-38 6/7 weeks) is of a higher rate when compared with later term deliveries.19, 20, 21 These short-term adverse outcomes include neonatal mortality,19 respiratory morbidity, neonatal intensive care unit admissions,20 longer durations of hospital stay at birth, increased rates of rehospitalization within the first year of life, and higher emergency department use.21 Due to the increased short-term adverse perinatal outcomes within the 5 weeks’ span of term, the Defining “Term” Pregnancy Workgroup22 redefined “term” pregnancy. “Early term” was defined when delivery occurred 37-38 6/7 weeks.
As early term offspring exhibit long-term morbidity resembling that of late preterm in several health categories,23, 24, 25, 26 and as endocrine and metabolic morbidity is more common in preterm born children, we sought to determine whether early term deliveries impact on the long-term pediatric endocrine and metabolic health of the offspring.
Section snippets
Materials and Methods
In this population-based cohort analysis, all term deliveries of singleton pregnancies occurring from January 1991 through December 2013 at the Soroka University Medical Center (SUMC) were included. SUMC is a regional tertiary center serving the entire population of southern Israel (The Negev: 60% of Israel’s area and 14.4% of Israel’s population, approximately 1,220,000 inhabitants).27
The study was approved by the SUMC Institutional Review Board Committee in accordance with the ethical
Results
During the study period 225,260 term deliveries met the inclusion criteria. Of those, 24% (n = 54,073) occurred between 37-38 6/7 weeks’ gestation and were referred to as early term deliveries. Deliveries occurring any time later (n = 171,187) were referred to as full-term deliveries.
Demographic characteristics and immediate perinatal outcomes of the different gestational age categories are presented in Table 1. Pregnancies ending at early term were more likely to be complicated by hypertensive
Principal findings
In this large cohort study, we demonstrate a significant and independent association between early term delivery and later endocrine and metabolic childhood and adolescence morbidity in the offspring. We found a 17% increase in morbidity rate in total (0- to 18-year follow-up), and a 30% increase at ages 5-18 years in the early term group of offspring. This significant association remained stable in several subgroup and sensitivity analyses.
Meaning of the findings
As morbidity was evaluated through hospitalization of
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Cited by (0)
The authors report no conflict of interest.
Cite this article as: Paz Levy D, Sheiner E, Wainstock T, et al. Evidence that children born at early term (37-38 6/7 weeks) are at increased risk for diabetes and obesity-related disorders. Am J Obstet Gynecol 2017;217:588.e1-11.