(333) First-trimester placental volume is associated with preeclampsia and small for gestational age birthweight

Objective:
To evaluate the association between first-trimester placental volume and subsequent development of preeclampsia (PE) and small for gestational age (SGA) birthweight.

Study Design:
Pregnant women at < 13+6 weeks’ gestation without fetal, umbilical cord or placental abnormalities were enrolled in this longitudinal cohort as part of the human placenta project. A 3D placental volume was obtained in the first trimester using VOCAL technique. Pregnancy outcomes were categorized into (1) PE only, (2) SGA only (birthweight < 10%ile), or (3) both (PE+SGA) which were compared to unaffected pregnancies. Placental volume was analyzed both continuously and categorically (≤10th, 10th –< 25th, and ≥ 25th percentiles). A cause-specific Cox proportional hazards model was used to assess the risk of each outcome. Survival analysis was performed using gestational age at delivery as the time scale.

Results:
368 patients had first trimester placental volume obtained. 29 patient had PE only, 27 had FGR only, 7 had FGR and PE, and 305 pregnancies were unaffected. Smaller placental volume was associated with the PE+SGA phenotype (HR: 0.26, 95% CI: 0.13–0.50, P< 0.001), but not with isolated PE (HR: 0.75, 95% CI: 0.51–1.09, P=0.13) or isolated SGA (HR: 0.96, 95% CI: 0.64–1.43, P=0.84) (Figure 1). Cumulative incidence plots demonstrated earlier delivery among those with the smallest placental volume < 10th percentile.

Conclusion:
First trimester placental volume is strongly associated with subsequent development of PE with concurrent SGA. First-trimester placental measurements may aid in identifying pregnancies at highest risk for early-onset, multi-system placental disease.