FETAL SEX AS A RISK FACTOR FOR FETAL GROWTH RESTRICTION OR SMALL FOR GESTATIONAL AGE

Objective: To evaluate the association between fetal sex and insufficient fetal growth (IFG), including fetal growth restriction (FGR) and small for gestational age (SGA). Materials and methods: A prospective cohort study was conducted at N.A. Semashko Republican Clinical Hospital from 2018 to 2023. A total of 611 women with singleton pregnancies diagnosed with IFG were included in the study, with FGR (n=435) and SGA (n=176). Results: Fetal sex in patients with IFG was associated with various factors, including parental age, age at menarche, maternal BMI, weight gain, blood pressure, hemoglobin levels, leukocyte counts, ALT and AST levels, blood creatinine, Doppler data of uteroplacental blood flow, CTG results, IFG variant (FGR or SGA), causes of IFG, prematurity, low birth weight (LBW), and the need for intensive care (IC) for the newborn. FGR, compared to SGA, was characterized by (p<0.05–0.001) a younger age of both parents, earlier age at menarche, greater weight gain, lower systolic and diastolic blood pressure in the first trimester, lower CTG indicators, lower hemoglobin levels, but higher creatinine, ALT, and AST levels, and an earlier gestational age at delivery. Female fetuses are more commonly associated with FGR, impaired blood flow in the uterine and middle cerebral arteries, LBW, severe preeclampsia (PE), and gestational arterial hypertension as causes of IFG as well as a higher need for IC in newborns. Male fetuses are more often linked to unknown causes of IFG, chronic arterial hypertension, moderate PE, and prematurity. Decision tree analysis revealed that the IFG variant is associated with fetal sex, parental age, the cause of IFG, LBW, and the need for IC. Conclusion: Fetal sex is interconnected with the IFG variant and numerous factors that contribute to or result from this condition. The specific nature of this relationship is influenced by the IFG variant (FGR or SGA), parental age, maternal and fetoplacental hemodynamics, and the maternal hemic, hepatic, and renal responses to pregnancy complicated by IFG. It is advisable to implement individualized centile tables adjusted for fetal sex during ultrasound monitoring. © 2025 Elsevier B.V., All rights reserved.