After diagnosing symmetric IUGR, which lab tests should be performed?

Diagnosing symmetric intrauterine growth restriction (IUGR) indicates that the fetus is uniformly small, often due to intrinsic factors affecting the growth potential of the fetus itself, such as chromosomal anomalies or congenital infections. In this context, maternal serum screening for viral infections is a critical step because viral infections like cytomegalovirus (CMV) and toxoplasmosis can lead to symmetric IUGR.

Testing for maternal serum markers can help identify potential infections that could adversely affect fetal development. Early identification of these infections allows for appropriate management and potential intervention, improving the chances for the fetus.

Other options are less relevant in this scenario. For instance, chest X-rays and fetal heart monitoring primarily assess respiratory conditions and fetal heart rate stability, not the essential causes of IUGR. Amniotic fluid analysis focuses on fetal distress or infections but is not specific for diagnosing symmetric IUGR causes. Ultrasound assessments can provide valuable information about growth and anatomy but do not directly identify viral or other infectious causes that may underlie symmetric IUGR. Thus, conducting maternal serum screenings is the most appropriate and relevant choice in this context.