Materials and Methods: Of all women (N=2037) who gave birth by caesarean section at Shohadaye-Tajrish hospital from 2015 to 2018, 100 women with MSAF were considered as the case group and 100 with normal amniotic fluid as the control group. The gestational age (GA) at caesarean delivery, neonate’s gender, 1 and 5 minutes Apgar scores (AS), and results of umbilical cord ABG analysis were compared between the groups using chi-square and t test. Statistical analysis was performed using SPSS version 24.0.

Results: The case group had a higher mean GA (39.19±1.52 weeks vs. 38.57±0.671; P < 0.001) and the control group had a higher mean 1-minute AS (9.58±0.25 vs. 8.47±0.327; P < 0.001), while the distribution of the neonate’s gender and frequency of low/normal 5-minute AS were not different between the groups (P > 0.05). The control group had a higher mean pressure of oxygen (32.44±24.89 vs. 25.83±16.63; P = 0.029); other parameters were not different between the two groups (P > 0.05).

Conclusions: The lower pressure of oxygen in neonates with MSAF, despite no difference in acidosis suggest that various factors have to be considered in order to differentiate pathologic and physiologic MSAF.