Screening for Intrauterine Growth Restriction
TORCH screening (Option A) is the most reasonable screening tool among the three choices provided, though its yield is extremely low and routine use is not cost-effective. However, the evidence strongly suggests that TORCH screening should be selective rather than routine, reserved for cases with specific clinical indicators beyond IUGR alone 1, 2, 3.
Evidence Against Routine TORCH Screening in IUGR
The available research consistently demonstrates poor diagnostic yield:
In a U.S. study of 75 IUGR infants who underwent TORCH workup, zero infants (0/75) had positive IgM titers for toxoplasma, rubella, CMV, or HSV, with only 1 infant having positive urine CMV culture 1.
A Korean study of 119 TORCH screenings in IUGR/SGA neonates found only one positive result (toxoplasmosis IgM), which was deemed false positive on repeat testing 2.
A Japanese study of 319 FGR cases found no maternal or congenital infections with toxoplasma, rubella, or HSV, though 6 cases (1.8%) had congenital CMV infection 3.
When TORCH Screening May Be Indicated
TORCH screening becomes more appropriate when IUGR is accompanied by:
- Hepatosplenomegaly, cataracts, or rash 1
- Thrombocytopenia, neutropenia, or direct hyperbilirubinemia 1
- Intracranial calcifications or hydrocephalus on imaging 1
- Structural abnormalities beyond isolated growth restriction 3
- Maternal history suggesting infection exposure 2
Why Urine Analysis (Option B) Is Not a Primary Screening Tool
Urinalysis has no established role as a screening tool for IUGR etiology. While urine CMV culture can detect congenital CMV infection, this is part of targeted TORCH evaluation rather than routine urinalysis 1, 2.
Why Chest X-Ray (Option C) Is Not a Screening Tool
Chest radiography has no role in screening for IUGR etiology and would expose the neonate to unnecessary radiation without diagnostic benefit.
The Actual Recommended Approach to IUGR Evaluation
The evidence-based workup for IUGR should focus on:
- Umbilical artery Doppler assessment, which significantly reduces perinatal deaths (RR 0.71) and guides delivery timing 4
- Evaluation of maternal factors: pregnancy-induced hypertension (19% of cases), tobacco use (43%), alcohol abuse (21%), illicit drug use (24%) 1
- Placental pathology when available: 67% of IUGR cases show placental abnormalities including infarcts, vasculitis/villitis 1
- Comprehensive anatomic ultrasound survey to identify structural anomalies 5
Cost-Effectiveness Considerations
The financial burden of routine TORCH screening is substantial without commensurate benefit: one study documented costs of $17,816 for TORCH titers, $1,318 for total IgM, $5,734 for CMV urine cultures, and $28,165 for head ultrasounds in 75 infants with zero confirmed infections 1.
Clinical Bottom Line
Among the three options presented, TORCH screening (A) is the only one with any potential diagnostic utility, but should be reserved for IUGR cases with additional clinical findings suggestive of congenital infection rather than applied routinely 1, 2, 3. The most evidence-based approach to IUGR involves Doppler assessment and evaluation of maternal/placental factors, neither of which are among your listed options 4.