The association high C-reactive protein (CRP) levels with the occurrence of preeclampsia (PE) is a growing matter of debate. This study aims to determine whether CRP concentration during pregnancy is a predictor of PE and whether nutritional status is a potential modifier of CRP in the context of this association.
Design and methods:
Twenty-two studies were included in a systematic literature review. A meta-analysis was performed using a subset of 17 publications with available data to calculate the weighted mean difference (WMD) of CRP in PE and control groups. A quality assessment was carried out using a scale specifically developed for this study.
The WMD of CRP between 664 women who developed PE and 2,823 controls was 1.73 mg/L (95% CI: 0.99-2.47). The heterogeneity among studies was high (I2 = 81.4; p < 0.001). The WMD was found to be lower in studies comprising PE and control groups with similar BMI (WMD = 0.85 [95% CI: 0.10-1.61]; I2 = 25.3%) compared to studies among which BMI was significantly elevated in the PE group (2.01 [95% CI: 1.23-2.78]; I2 = 0.0%), which may explain the high heterogeneity of pooled data. Only 30% of the articles were classified as high quality.
Our findings suggest that women with higher levels of CRP may have an increased risk of developing PE. Some factors should be considered in evaluating this association, such as nutritional status, gestational age at blood collection and specimen type. Further studies of high methodological quality are urgently needed.