(865) Placental pathology in nulliparas with gestational hypertension and preeclampsia

Friday, January 31, 2025

10:30 AM – 12:30 PM

Submitting Author and Presenting Author(s)

Nadine Sunji, MD (she/her/hers)

Postdoctoral Fellow
Medical College of Wisconsin
Milwaukee, Wisconsin, United States

Coauthor(s)

ML

Melodee Liegl, MA

Medical College of Wisconsin
Milwaukee, Wisconsin, United States
AP

Amy Y. Pan, PhD

Medical College of Wisconsin
Milwaukee, Wisconsin, United States
Alexa A. Freedman, PhD (she/her/hers)

Northwestern University
Chicago, Illinois, United States
LE

Linda M. Ernst, MD

Endeavor Health
Evanston, Illinois, United States
Anna Palatnik, MD

Associate Professor
Medical College of Wisconsin
Milwaukee, Wisconsin, United States

Objective: To investigate placental pathology patterns in first-time mothers with gestational hypertension and preeclampsia.

Study Design: This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be. The present analysis included nulliparous participants with singleton gestations who developed gestational hypertension or preeclampsia and had placental pathology reports available. Placental characteristics and pathologies were described and compared between different types of hypertensive disorders of pregnancy (HDP) and by gestational age at HDP diagnosis using univariate and bivariate analyses.

Results: Of 543 participants who met inclusion criteria, 297 (54.7%) had gestational hypertension, and 246 (45.3%) had preeclampsia. Of these, 228 (42.3%) had an HDP diagnosis prior to 37 weeks. The rate of acute fetal and maternal placental inflammation was higher among those with term preeclampsia (46.2%) and gestational hypertension (42.1%) and lower among placentas of preterm preeclampsia (12.6%, p< .001; Table 1). In contrast, the rate of maternal vascular malperfusion was highest in preterm preeclampsia (62.1%) and lowest in gestational hypertension (29.6%, p< .001). The rates of fetal vascular malperfusion did not differ between HDP phenotypes. Table 2 examined placental findings by gestational age at diagnosis of ≥37 weeks, 34-36 weeks, and < 34 weeks. Presence of acute maternal and fetal inflammatory response increased with advancing gestation (19.5% at < 34 weeks, 23.8% at 34-36 weeks, and 49.8% at ≥37 weeks; p< .001) while the prevalence of maternal vascular malperfusion decreased with advancing gestation (48.8% at < 34 weeks, 44.8% at 34-36 weeks, and 31.2% at ≥37 weeks; p< .001).

Conclusion: Maternal vascular malperfusion lesions in the placenta were more common in early-onset HDP while acute inflammatory lesions were more common in late-onset HDP. This distinction helps in understanding that early- and late-onset HDP may have different underlying pathological mechanisms.