Objective

To identify risk factors associated with the occurrence of meconium aspiration syndrome (MAS) among neonates.

Methods

A retrospective case-control study in a university affiliated tertiary medical center, including all neonates born with meconium stained amniotic fluid (MSAF) between March 2011 and March 2020. Patients were categorized by the occurance of MAS. Demographic, pregnancy and delivery characteristics were compared between the two groups. Risk factors for MAS were analyzed.

Results

Of 90,579 singleton deliveries, a total of 11,856 with MSAF were included. Of these newborns, 78 (0.66%) were diagnosed with MAS Four factors were independently associated with MAS: delivery at <38 0/7 weeks (aOR [95% CI]: 3.48 (1.02-11.84), p=0.046); higher body mass index (aOR [95% CI]: 1.09 (1.02-1.16), p=0.003); lower amniotic fluid index (aOR [95% CI]: 0.99 (0.98-0.99), p=0.032); higher white blood cell count (aOR [95% CI]: 1.11 (1.02-1.20), p=0.009). The presence of one, two and three of the above mentioned risk factors yielded a risk for MAS of 0.8%, 2.5% and 100% respectively.

Conclusion

We identified independent risk factors for MAS and developed a risk score calculator. This tool may assist physicians in the management of deliveries complicated by MSAF.