Routine screening for intrauterine growth retardation in Germany: low sensitivity and questionable benefit for diagnosed cases

Background. Antenatal screening for fetal growth retardation has proven effective in detecting at-risk pregnancies under study conditions. It is also widely believed to improve pregnancy outcomes. We assessed sensitivity of antenatal screening routines for intrauterine growth retardation under routine service conditions in Germany. We then compared pregnancy management and outcome in small for gestational age neonates with antenatally diagnosed growth retardation to neonates whose growth retardation had remained undetected. Methods. Historical prospective study covering all 2378 singleton pregnancies with antenatal records delivered within a one-year period at a tertiary level maternity hospital in Germany. Antenatal records were linked with pregnancy outcome data. Results. The sensitivity of screening routines based on ultrasound and non-systematic followup investigations was 32% as compared to 80-90% reported for ultrasound screening under study conditions. An antenatal diagnosis of intrauterine growth retardation was associated with a 5 times higher rate of preterm delivery (p<0.001), mainly as a consequence of medical interventions to avoid fetal compromise, when compared to new-horns with growth retardation not detected before delivery; admission rates to neonatal care unit were 3 times higher (p<0.001).The proportion of low Apgar scores and low cord pH, indicating fetal distress, was not significantly different in detected and undetected cases. Conclusion. Screening routines for intrauterine growth retardation currently used in Germany miss the majority of cases and do not contribute towards improved pregnancy outcome in detected cases. A benefit of elective preterm delivery in the management of suspected intrauterine growth retardation was not evident.