Prediction of adverse pregnancy outcomes using crown-rump length at 11
to 13+6 weeks of gestation: a retrospective cohort study
Abstract
Objectives: To assess the risk of adverse pregnancy outcomes associated
with fetuses with a smaller or larger than expected crown-rump length
(CRL). Design: Retrospective cohort study Setting: A single center in
South Korea Population: A total of 960 healthy women who conceived after
in vitro fertilization. Methods: We constructed reference charts for CRL
measurements between 11 and 13+6 weeks of gestation according to the
gestational age. Small and large fetal CRLs were defined as CRLs below
the tenth and above the ninetieth centiles, respectively. Multiple
logistic regression was used to determine the risk of adverse pregnancy
outcomes associated with a small or large fetal CRLs. Main Outcome
Measure: Adverse pregnancy outcomes including preterm delivery, low
birth weight, smaller-than-gestational-age (SGA),
larger-than-gestational-age (LGA), macrosomia, and gestational diabetes.
Results: A smaller than expected CRL was associated with an increased
risk of SGA (adjusted odds ratio [aOR], 2.79; 95% confidence
interval [CI], 1.53–5.08; p < 0.001) and preterm delivery
before 34 gestational weeks (aOR, 6.48; 95% CI, 1.36–30.79; p =
0.019). A larger than expected CRL was associated with an increased risk
of LGA, even after adjustment for well-known risk factors of macrosomia
(aOR, 3.67; 95% CI, 2.04–6.59; p < 0.001), and a decreased
risk of gestational diabetes (aOR, 0.10; 95% CI, 0.01–0.76; p =
0.026). Conclusions: A larger than expected CRL at 11 to 13+6 weeks’
gestation is independently associated with the development of LGA
neonates and could be used as a predictor of excessive fetal growth.