Fetal Growth Restriction: A Comprehensive Review of Major Guidelines.

Importance: Fetal growth restriction (FGR) is a common pregnancy complication and a significant contributor of fetal and neonatal morbidity and mortality, mainly due to the lack of effective screening, prevention, and management policies.

Objective: The aim of this study was to review and compare the most recently published influential guidelines on the management of pregnancies complicated by FGR.

Evidence acquisition: A descriptive review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Society for Maternal-Fetal Medicine, the International Federation of Gynecology and Obstetrics, the International Society of Ultrasound in Obstetrics and Gynecology, the Royal College of Obstetricians and Gynecologists, the Society of Obstetricians and Gynecologists of Canada (SOGC), the Perinatal Society of Australia and New Zealand, the Royal College of Physicians of Ireland, the French College of Gynecologists and Obstetricians (FCGO), and the German Society of Gynecology and Obstetrics on FGR was carried out.

Results: Several discrepancies were identified regarding the definition of FGR and small-for-gestational-age fetuses, the diagnostic criteria, and the need of testing for congenital infections. On the contrary, there is an overall agreement among the reviewed guidelines regarding the importance of early universal risk stratification for FGR to accordingly modify the surveillance protocols. Low-risk pregnancies should unanimously be evaluated by serial symphysis fundal height measurement, whereas the high-risk ones warrant increased sonographic surveillance. Following FGR diagnosis, all medical societies agree that umbilical artery Doppler assessment is required to further guide management, whereas amniotic fluid volume evaluation is also recommended by the ACOG, the SOGC, the Perinatal Society of Australia and New Zealand, the FCGO, and the German Society of Gynecology and Obstetrics. In case of early, severe FGR or FGR accompanied by structural abnormalities, the ACOG, the Society for Maternal-Fetal Medicine, the International Federation of Gynecology and Obstetrics, the Royal College of Obstetricians and Gynecologists, the SOGC, and the FCGO support the performance of prenatal diagnostic testing. Consistent protocols also exist on the optimal timing and mode of delivery, the importance of continuous fetal heart rate monitoring during labor, and the need for histopathological examination of the placenta after delivery. On the other hand, guidelines concerning the frequency of fetal growth and Doppler velocimetry evaluation lack uniformity, although most of the reviewed medical societies recommend an average interval of 2 weeks, reduced to weekly or less when umbilical artery abnormalities are detected. Moreover, there is a discrepancy on the appropriate timing for corticosteroids and magnesium sulfate administration, as well as the administration of aspirin as a preventive measure. Cessation of smoking, alcohol consumption, and illicit drug use are proposed as preventive measures to reduce the incidence of FGR.

Conclusions: Fetal growth restriction is a clinical entity associated with numerous adverse antenatal and postnatal events, but currently, it has no definitive cure apart from delivery. Thus, the development of uniform international protocols for the early recognition, the adequate surveillance, and the optimal management of growth-restricted fetuses seem of paramount importance to safely guide clinical practice, thereby improving perinatal outcomes of such pregnancies.