Maternal serum 25-hydroxyvitamin D and C-reactive protein levels in pregnancies complicated with threatened preterm labour

Abstract

Objective and methods: To measure 25-hydroxyvitamin D [25(OH)D] and C-reactive protein (CRP) serum levels in singleton gestations complicated with threatened preterm labour (TPL, n = 59) and compare to normal controls matched for gestational age (n = 64). Cases were treated after blood sample according to institutional protocol. Also, analyte levels were compared among cases according to the outcome.

Results: Mean serum 25(OH)D levels were similar between cases and controls, with median white blood cell count and CRP levels found significantly higher in TPL cases. Women with TPL delivering preterm displayed shorter mean cervical lengths along with higher CRP and lower 25(OH)D serum levels when compared to those delivering at term. Two multiple linear regression models were constructed to analyse factors related to gestational age at delivery (pooled analysis and only those with TPL). In both models, gestational age positively correlated to cervical length and inversely to CRP levels; whereas, in the TPL model, only 25(OH)D levels correlated positively.

Conclusion: Women complicated with TPL showed similar serum 25(OH)D yet higher CRP levels as compared to controls. TPL cases delivering preterm displayed lower 25(OH)D and higher CRP correlated levels.

Chinese abstract

目标和方法: 选择孕周匹配的先兆早产单胎妊娠孕妇(TPL, n= 59)和正常对照组孕妇(n = 64), 检测她们的25-羟维生素D [25(OH) D]和C-反应蛋白(CRP) 血清水平。根据实验设计采集血清样本后对病例采取治疗。同时, 根据治疗最终结局比较两组研究对象的血清检测水平。

结果: 平均血清25(OH) D水平在病例和对照之间是相似的, 中位白细胞计数和CRP水平在TPL病例中显著升高。在最终分娩的病例中, 发生早产的TPL孕妇具有更短的平均宫颈长度以及更高的CRP和更低的25(OH) D血清水平。构建两个多元线性回归模型以分析与分娩孕周相关的因素(合并分析, 仅合并TPL的病例) 。在两种模型中, 分娩孕周与宫颈长度呈正相关, 与CRP水平呈负相关; 而在TPL模型中, 只有25(OH) D水平正相关。

结论: 与对照组相比, 先兆早产的孕妇具有相似的血清25(OH) D水平, 但其CRP水平更高。TPL病例中发生早产与更低的25(OH) D和更高的CRP水平相关。

Keywords:

• C-reactive protein
• pregnancy
• preterm delivery
• preterm labour, vitamin D

Declaration of interest

The authors declare having no conflicts of interest.

The present study was supported by the grant PI-0487/2011 from the “Fundación Pública Andaluza Progreso y Salud” for Financiation of Biomedical Research in Health Sciences in Andalucía (Spain) to study hormone factors in preterm labour.