The influence of blood donation before pregnancy on neonatal birth weight

To evaluate the effect of blood donation before pregnancy on neonatal birth weight.

A total of 14996 women with singleton pregnancies at full-term in Ningbo Medical Center Lihuili Hospital and Ningbo Women's and Children's Hospital from November 2019 to November 2020 were enrolled in this study. Detailed records of whole blood donation before pregnancy were obtained through Alipay software. The records were classified into three groups: nondonors, low-frequency donors and high-frequency donors according to the total numbers of blood donations in the 3-year period before pregnancy. The demographics and clinical information of the enrolled participants and their fetuses were collected from electronic medical records (EMRs). The effect of blood donations in the 3-year period before pregnancy on neonatal birth weight was analyzed.

There was no significant difference in neonatal birth weight among the three groups (P = 0.373). In line with this, there was no association between the number of blood donations in the 3-year period before pregnancy and neonatal birth weight (β = 14.5; 95% confidence interval [CI]: -3.9, 31.4; P = 0.094) in the bootstrapped multivariate linear regression analysis models, adjusted for maternal age, number of pregnancies, number of deliveries, gestational age, mode of delivery, years of education and blood type in pregnant women. Compared to the nondonors, the risk of fetal macrosomia was higher in both low-frequency donors and all donors (OR: 1.539, 95% CI: 1.058, 2.134, P = 0.016; OR: 1.454, 95% CI: 1.033, 1.952, P = 0.021, respectively), in the bootstrapped binary logistic regression analysis models after adjusting for the variables mentioned above.

Our study showed that maternal blood donation in the 3-year period before pregnancy may not lead to a reduction in neonatal birth weight, but may be associated with the incidence of fetal macrosomia.