Delivery of a Fetus with a Non-Reassuring Status Is Associated with Significant Maternal Morbidity

Abstract

Objectives: When a labor process is complicated by non-reassuring fetal status (NRFS), obstetricians focus on delivery to optimize neonatal status. We explored maternal morbidity in the setting of NRFS. Our hypothesis is that delivery of a live newborn with NRFS is associated with significant maternal morbidity. Design, Participants, Setting, and Methods: A large retrospective cohort study of 27,886 women who delivered between January 2013 and December 2016 in a single health system was studied. Inclusion criteria included (1) women over the age of 18 at the time of admission; (2) singleton pregnancy; (3) live birth; and (4) gestational age greater than or equal to 37 weeks at the time of admission. NRFS was defined as umbilical cord pH less than or equal to 7.00, fetal bradycardia, late decelerations, and/or umbilical artery base excess ≤-12. Univariate and multivariate logistic regression and propensity score analyses were performed, and propensity score adjusted odds ratios (AORPS) were derived. p values <0.05 were considered statistically significant. Primary outcomes are maternal blood transfusion, maternal readmission, maternal intensive care unit (ICU) admission, and cesarean delivery in relation to umbilical artery pH, fetal bradycardia, and late decelerations.

Results: Umbilical artery pH less than or equal to 7 was associated with maternal blood transfusion (AORPS 6.83 [95% CI 2.22-21.0, p < 0.001]), maternal readmission (AORPS 12.6 [95% CI 2.26-69.8, p = 0.0039]), and cesarean delivery (AORPS 5.76 [95% CI 3.63-9.15, p < 0.0001]). Fetal bradycardia was associated with transfusion (AORPS 2.13 [95% CI 1.26-3.59, p < 0.005]) and maternal ICU admission (AORPS 3.22 [95% CI 1.23-8.46, p < 0.017]). Late decelerations were associated with cesarean delivery (AORPS 1.65 [95% CI 1.55-1.76, p < 0.0001]), clinical chorioamnionitis (AORPS 2.88 [95% CI 2.46-3.37, p < 0.0001]), and maternal need for antibiotics (AORPS 1.89 [95% CI 1.66-2.15, p < 0.0001]). Umbilical artery base excess less than or equal to -12 was associated with readmission (AORPS 6.71 [95% CI 2.22-20.3, p = 0.0007]), clinical chorioamnionitis (AORPS 1.89 [95% CI 1.24-2.89, p = 0.0031]), and maternal need for antibiotics (AORPS 1.53 [95% CI 1.03-2.26, p = 0.0344]).

Limitations: The retrospective design contributes to potential bias compared to the prospective design. However, by utilizing multivariate logistic regression analysis with a propensity score method, specifically inverse probability of treatment weighting, we attempted to minimize the impact of confounding variables. Additionally, only a portion of the data set had quantitative blood losses recorded, while the remainder had estimated blood losses.

Conclusion: NRFS is associated with significant maternal complications, in the form of increased need for blood transfusions, ICU admissions, and increased infection and readmission rates. Strategies for minimizing maternal complications need to be proactively considered in the management of NRFS.

Keywords: Bradycardia; Cesarean; Deceleration; Delivery; Fetal; Late; Maternal; Morbidity; Non-reassuring; Readmission; Transfusion.