The impact of maternal cardiovascular status prior to labor on birth outcomes: an observational study.

OBJECTIVES

To evaluate the diagnostic accuracy of maternal characteristics, computerized cardiotocography (cCTG), maternal hemodynamics, and fetal Doppler in predicting adverse perinatal outcomes (APO) in healthy term pregnancies before labor onset.

METHODS

In this prospective observational study, 395 term pregnant women were enrolled. Data on obstetric history, cCTG, maternal hemodynamics, and fetal ultrasound were collected. Women undergoing labor induction were excluded. The primary endpoint was a composite APO, defined as cesarean or operative vaginal delivery due to pathological CTG, 5-min Apgar <7, umbilical artery pH <7.1 and/or base excess >12 mmol/L, or NICU admission. A secondary outcome, "objective APO", excluded operative delivery for pathological CTG. Logistic regression analyses were performed to assess predictors of APO.

RESULTS

Among 307 women with spontaneous labor, 41 (13.36 %) experienced a composite APO. These women were less often multiparous (7.32 vs. 27.07 %, p=0.01), had higher systemic vascular resistance [SVR: 1,353 (1,209-1,498) vs. 1,249 (1,071-1,438) dyn s cm-5, p=0.01], and lower short-term variability [STV: 7.5 (6.2-10.0) vs. 9.1 (7.6-11.0) ms, p<0.01]. Fetal Doppler indices, including cerebro-placental ratio, showed no significant differences. ROC analysis identified SVR >1,135 dyn s cm-5 (OR 6.92, 95 % CI 2.08-23.03) and STV ≤7 ms (OR 3.95, 95 % CI 1.97-7.92), as optimal predictors. Multivariate analysis confirmed STV, SVR, and parity as independent predictors. In the secondary analysis of "objective APO", both SVR and STV remained significant predictors, and the multivariable model demonstrated excellent discrimination [AUC 0.931 (95 % CI 0.896-0.957)].

CONCLUSIONS

In term pregnancies, maternal hemodynamic assessment and cCTG performed before labor may improve the identification of women at increased risk of APO.