Relationship between pregnancy risk factors and ABG umbilical cord of the infant after birth

Newborn assessment using Umbilical arterial blood gas (UABG) analysis is more objective than other methods for predicting neonatal outcome. Acidic neonates may be at risk of adverse consequences after birth. This study was conducted to determine the risk factors during pregnancy and their effect on the arterial blood gas (ABG) of the neonates after birth.

This cross-sectional study was conducted on 1794 mothers hospitalized for termination of pregnancy who were referred to Imam Hossein Medical Training Center in Tehran during the years 2021-2023. Information was collected through a checklist before and after delivery. Also, to perform ABG and VBG, a blood sample was taken from the neonate's umbilical cord and extracted from the file. Data analysis was done using SPSS version 25 statistical software.

In this study, between different ABG levels and maternal characteristics, BMI, oligohydramnios, placental abruption, IUGR, acreta, PPROM, delivery mode, and labor with induction, COVID-19, HTN, heart disease, anemia, diabetes, gestational diabetes, pre-eclampsia, eclampsia and addiction statistically significant difference was observed (P < 0.05). A significant difference was observed between preterm infants, weighing less than 2500 grams, Apgar score lower than 7 in the first and fifth minutes, and hospitalization in NICU with different levels of ABG PH (P < 0.05). In the multivariable model, fetal distress (OR: 3.51, 95% CI: 1.91-6.44), GDM (Insulin, OR = 5.08; 95% CI: 2.60-9.95), Gestational age at birth (<37, OR = 2.25; 95% CI: 1.23-4.12) were associated with an increased odds of ABG acid level. Also, in the multivariable model, fetal distress (OR: 2.30, 95% CI: 1.70-3.12), GDM (Insulin, OR = 2.48; 95% CI: 1.70-3.64 and diet, OR = 2.42; 95% CI: 1.46-4.02), Labor (Induction, OR = 1.61; 95% CI: 1.10-2), Gestational age at birth (<37, OR = 1.43; 95% CI: 1.06-1.92) were associated with an increased odds of ABG hypoxia level.

It can be concluded that umbilical cord blood gas is closely related to neonatal prognosis and is a useful tool for screening newborns at risk. ABG should be considered for all deliveries, as it is an accurate screening test for hypoxia and neonatal asphyxia.