Association of cesarean delivery on maternal request with neonatal iron stores at birth

Cesarean has been suggested to decrease neonatal iron stores at birth. However, few studies have differentiated the effect induced by cesarean operation from that related to medical indications.

We aimed to estimate the association of cesarean delivery on maternal request (CDMR), a subtype of cesarean without any medical indications, with a spectrum of indicators reflecting iron stores at birth.

This prospective cohort study involved 288 term singleton neonates born to women without any complications by CDMR or spontaneous vaginal delivery (SVD). Measured hematological iron-related indicators in cord blood included serum ferritin (SF), hemoglobin (Hb), red blood cell (RBC), and hematocrit (Hct). Blood flow volume (BFV) of cord vein when clamping was measured to reflect placental transfusion status during birth. Quantile regression was used to assess the association between delivery mode and the iron store indicators.

CDMR (n = 154) versus SVD group (n = 134) had lower conditional median cord blood SF (-34.80; 95% CI -64.70, -4.90 μg/L; P = 0.02), Hb (-10.67; 95% CI -18.87, -2.47 g/L; P = 0.01), RBC (-0.30; 95% CI -0.48, -0.12 ×10¹²/L; P = 0.002), and Hct (-3.06; 95% CI -6.08, -0.04 %; P = 0.047). The BFV was higher in CDMR than SVD group at the 25th centile (0.51; 95% CI 0.19, 0.82 ml/cm³; P = 0.002), median (0.49; 95% CI 0.04, 0.95 ml/cm³; P = 0.03) and the 75th centile (0.54; 95% CI 0.06, 1.03 ml/cm³; P = 0.03).

The cesarean operation per se likely hampered placental transfusion from mother to neonate and decreased iron stores at birth.