Meconium aspiration syndrome - the experience of a tertiary center

Background: Approximately 5 % of infants born with a meconium-stained amniotic fl uid (MSAF) develop meconium aspiration syndrome (MAS). Aim: The aims of this study were to analyse demographic data, morbidity and mortality associated with MAS and to identify possible risk factors. Methods: Retrospective chart review of newborns with MAS delivered at a tertiary center from January 1st, 1997 to December 31st, 2008. Results: MAS was responsible for 1.4 % of all Neonatal Intensive Care Unit (NICU) admissions, with a trend towards a decreasing incidence during the duration of the study, especially in the cases of thin meconium. Seventy two newborns were analysed during the study period: 55.6 % (n = 40) were of the female gender, 62.5 % were delivered by caesarean section, 93 % had > 36 weeks of gestational age and 91.2 % had a birth weight over 2500 g. Sixty-nine percent had an Apgar score < 7 at 1 minute and 23.6 % an Apgar score < 7 at 5 minutes; foetal bradicardia was present in 26.4 % of the newborns and tachycardia in 1.4 %. The presence of meconium was associated with severe asphyxia and carried a bad prognosis with an increased risk of developing hypoxia (58.3 %), need of mechanical ventilatory support (43.1 %), respiratory and/or metabolic acidosis (30.6 %), pulmonary hypertension (11.1 %) and hypoxic ischemic encephalopathy (29.2 %). The mortality rate was 2.8 %. Thick meconium was associated with higher morbidity and mortality rates. Conclusions: The number of admissions for MAS has been decreasing mostly because of a lower admission rate due to thin meconium; the number of cases with thick meconium has remained constant throughout the years. An Apgar score < 7 at 1 minute and signs of foetal distress during labour were associated with MAS. The MAS related morbidity remains signifi cant.