A Cut-off Value for Gestational Week at Birth for Better Perinatal Outcomes in Early- and Late-Onset Fetal Growth Restriction.

Objective: Prediction of cut-off value for gestational week at birth for better perinatal outcomes in early- and late-onset fetal growth restriction (FGR).

Materials And Methods: This study consists of 83 singleton pregnancies with FGR that were diagnosed antenatally and confirmed postnatally between January 2017-April 2018. We used the 34 gestational week as a cut-off for early- and late-onset FGR discrimination.

Results: Early- and late-onset FGRs were detected in 22 (26.5%) and 61 (73.5%) of the cases, respectively. Expectant management significantly improved birth weight and Apgar scores at the 1, 5, and 10 minute in early-onset FGR cases (p=0.001, p=0.019, p=0.002, and p=0.001,respectively). Similar analysis revealed no significant improvements in late-onset FGR (p=0.151, p=0.727, p=0.951 and p=0.477, respectively). Umbilical cord blood gas pH was found to be similar between management modalities in both the early- and late-onset groups (p=0.186 and p=0.456, respectively). Gestational week 33.5 was found to be the threshold for better Apgar scores at the 1, 5, and 10 minute according to ROC curve analysis. Percentiles of 4.5, 2.5, and 4.5 were cut-off values for better Apgar scores at the 1, 5, and 10 minute, respectively.

Conclusion: Expectant management must be the first choice to improve Apgar scores in early-onset FGR cases, and gestational week 33.5 must be considered as a threshold for delivery. Immediate delivery might be the choice in late-onset FGR in necessary cases. However, etiology-based management and perinatal surveillance might also be considered to improve prematurity-related neonatal complications.