Fetal growth restriction may be the result of several possible conditions, including maternal, fetal and placental.
Q. A 34-year-old G1P0 is found to have a fetus with an estimated weight of 500 g infant at 28 weeks' gestation. Gestational dating had been confirmed by a first trimester ultrasound. How would you initially evaluate this patient?
A The definition of fetal growth restriction (FGR) is an estimated fetal weight (EFW) of less than the 10th percentile for gestational age.1 At 28 weeks' gestation, the 10th percentile for fetal weight is 720 g, so this fetus meets clinical criteria for FGR.2
FGR may be a result of several possible conditions, including maternal (eg, vascular disease), fetal (eg, aneuploidy, other genetic syndromes, infection), and placental (eg, insufficiency).3 This differential diagnosis should be considered at the time of diagnosis of FGR and reassessed subsequently at each visit based on the clinical picture. Determination of the etiology may help to guide clinical management.
A detailed ultrasound should focus on detection of fetal, umbilical cord, or placental anomalies. Fetal biometry should include measurements of the long bones. In addition to major congenital anomalies, the fetus should be assessed for ultrasound markers of fetal aneuploidy or fetal infection.