Association of the maternal serum albumin level with fetal growth and fetal growth restriction in term-born singletons: a prospective cohort study

Objective: To investigate the association of the maternal serum albumin (MAlb) level with fetal growth and fetal growth restriction (FGR) risk in term-born singletons.

Design: Prospective cohort study.

Setting: Four hospital maternity units of the Tongji Maternal and Child Health Cohort study initiated from September 2013 to April 2016 at Wuhan City, in central China.

Patient(s): A total of 3,065 mother-offspring pairs.

Intervention(s): None.

Main outcome measure(s): Fetal growth was evaluated by birth weight (BW) and birth length. Fetal growth restriction was defined as BW below the 10th percentile.

Result(s): All MAlb levels were within the upper limit of normal. After adjustment for liver function parameters, inflammatory indicators, and others, a reverse U-shaped relationship between MAlb and fetal growth was observed. Specifically, BW increased significantly with an increasing MAlb level when the MAlb level was <36.1 g/L (per g/L: β = 36.8; 95% CI, 0.8, 72.7) but decreased with increasing the MAlb level when the MAlb level was >36.1 g/L (per g/L: β = -15.1; 95% CI, -21.2, -8.9). There was a similar association between MAlb and birth length. Furthermore, the adjusted odd ratios of FGR across increasing tertiles of the MAlb levels were 1.0 (reference), 1.1 (0.7, 1.8), and 1.7 (1.0, 2.6).

Conclusion(s): There was a reverse U-shaped association between MAlb and fetal growth. A higher MAlb level was associated with an increased risk of FGR.

Clinical trial registration number: NCT03099837.