The effect of the prognostic nutritional index in the first trimester on birth weight: A retrospective study

Abstract Aim The study aimed to investigate the effect of the maternal prognostic nutritional index (PNI) in the first trimester on birth weight. Methods This retrospective study was conducted on term births between 2015 and 2022. The subjects were classified into three categories based on their birth weight: small gestational age (SGA), adequate gestational age (AGA), and large gestational age (LGA). The values of PNI, albumin (ALB), and hemoglobin (HB) were determined in the first trimester. PNI, ALB, and HB levels, demographic, obstetric, and neonatal outcomes were compared in the three groups. Results A total of 302 singleton pregnancies were included, with 79 cases classified as SGA (26.2%), 147 cases as AGA (48.6%), and 76 cases as LGA (25.2%). The mean ages and body mass index (BMI) of the groups were found to be similar ( p < 0.05). HB (12.3 ± 1.28 g/dL), ALB (3.5 ± 0.37 g/dL), and PNI (35.7 ± 3.78) levels were found to be lower in the SGA group ( p < 0.05). The cut‐off values for ALB and PNI were 3.5 g/dL and 35, respectively (80.3% and 81% sensitivity and 54.4% specificity). A positive correlation was identified between the 1 min Apgar score and both ALB and PNI ( p = 0.002, r = 0.176). Discussion A reduction in PNI, HB, and ALB levels was observed in the SGA group, whereas no significant difference was identified in the LGA group. To achieve an adequate birth weight, it is recommended that the nutritional status and anemia of the mother be improved before and during pregnancy.