Antenatal Maternal Hemoglobin Level and Severe Maternal Morbidity

Area of Science:

• Obstetrics and Gynecology
• Maternal Health
• Anemia Research

Background:

• Prior studies indicate antenatal anemia is a risk factor for severe maternal morbidity (SMM).
• Administrative definitions for SMM, including CDC criteria, have limitations in positive predictive value.
• This study validates SMM criteria using gold-standard chart review.

Purpose of the Study:

• To investigate the association between hemoglobin levels at delivery admission and SMM.
• To compare SMM definitions using administrative data versus gold-standard chart review.
• To identify anemia as a risk factor for SMM with improved accuracy.

Main Methods:

• Retrospective case-control study of deliveries (2016-2019) at a high-acuity hospital.
• Screening of administrative data for CDC-defined SMM, followed by chart review for gold-standard confirmation.
• Bivariate analyses and multiple logistic regression to assess the relationship between admission hemoglobin and SMM.

Main Results:

• Anemia at delivery admission was more prevalent in SMM cases (43.9%) than controls (24.2%).
• SMM cases had lower admission hemoglobin levels (11.2 ± 1.7 g/dL) compared to controls (11.9 ± 1.3 g/dL).
• Lower admission hemoglobin was independently associated with an increased risk of gold-standard SMM (aOR = 0.76).

Conclusions:

• Lower hemoglobin levels at delivery admission are significantly associated with an increased risk of severe maternal morbidity.
• Anemia identified at delivery admission is a critical predictor of SMM.
• Utilizing gold-standard chart review enhances the accuracy of SMM risk factor identification.