Phenotypes of fetal macrosomia and risk of stillbirth among term deliveries over the previous four decades

Abstract

Objectives To evaluate the association between macrosomia and stillbirth over the previous four decades and to determine the consistency of the relationship. Methods This was a population‐based retrospective cohort study using United States Natality and Fetal Death Data from 1982 to 2017 and restricted to the gestational age range of 37‐41 weeks inclusive. Macrosomia was defined as birthweight ≥4000 g and subdivided into its grades as previously recommended: grade 1 (4000‐4499 g), grade 2 (4500‐4999 g), and grade 3 (≥5000 g). We calculated temporal trends of stillbirth among fetuses with macrosomia over the years using joinpoint regression. We generated odds ratios from adjusted binomial logistic regression models to examine the association between macrosomia and risk of stillbirth stratified by grades using normal‐weight infants (2500‐3999 g) as referent. Results Within the fetal macrosomia group, the rate of stillbirth declined from 2.04/1000 in 1982 to 1.05/1000 by the end of the study period (2017), representing a drop of about 48.5%. For the normal‐weight fetuses, stillbirth rate declined from 1.95/1000 to 0.83/1000, equivalent to a decline of 57.4%. Macrosomia was significantly associated with elevated risk for stillbirth: grade 2 (OR = 1.27; 95% CI = 1.22‐1.32) and grade 3 (OR = 5.97; 95% CI = 5.69‐6.22). Conclusions Fetal macrosomia is a significant risk factor for fetal demise with the worst intrauterine survival observed among those classified as grade 3. Fetal macrosomia is a heterogeneous rather than a homogeneous entity in terms of risk profiles, and this needs to be considered in future policy guidelines.

Fetal Growth Acceleration – Current Approach to the Big Baby Issue

“…Macrosomia was defined as weight >4000 g and further divided into subgroups of grade one -4000-4499g, grade 2 -4500-4999 g, and grade 3 ->5000 g. The authors observed a substantial fall in stillbirth rates during the study period in both macrosomic and normal weight fetuses. Grade 1 macrosomia was not a stillbirth risk factor (0,95 stillbirths per 1000 pregnancies), while grade 2 macrosomia increased the risk 2 fold (2,43/1000) and grade 3 had a stillbirth rate (13,03/1000) -similar to that of low birthweight fetuses (15.54/1000) [34].…”

Trends in childhood viable pregnancy and risk of stillbirth in the United States

“…We used joinpoint regression, which is a modeling technique, to detect the change in the rate of events over time. [16] We also calculated the average annual percentage change (AAPC) for trends in rates of viable pregnancies, live birth and stillbirth in both child and teen mothers over the study period.…”

Risk of Stillbirth Among Foreign-Born Mothers in the United States

“…Traditional fetal mortality rates are expressed as deaths per 1000 total births, while fetuses-at-risk rates are expressed per 1000 fetuses at risk of mortality. This technique has been recommended as a more sensitive approach to understand the intersection of birthweight-specific and gestational age-specific perinatal mortality risks [8,9]. Adjusted Cox proportional-hazards regression models measuring the association between maternal nativity and stillbirth for the entire study population and among various racial/ethnic groups were created.…”