[Neonatal morbidity associated with meconial amniotic fluid].

BACKGROUND: The significance of meconium-stained amniotic fluid (MSAF) is discussed, both in regards to obstetric and pediatric management. The primary concerns regarding MSAF have been its significance as a sign of fetal distress/perinatal asphyxia and the prevention of associated morbidity such as meconium aspiration syndrome. The objectives of our study were: (1) To know the incidence and type of MSAF, (2) to study the associated morbidity in newborns with MSAF admitted to the Neonatal Care Unit (NCU), and (3) to analyze the perinatal differences between newborns with moderate versus thick MSAF.

PATIENTS AND METHODS: A retrospective study was performed to know the incidence of MSAF in all of the deliveries in our hospital during a 4 year period. The consistency of meconium was classified into 3 classes, thin (light), moderate or thick (heavy). On the other hand, a prospective analysis was undertaken to determine the morbidity of all meconium-stained neonates admitted to our NCU during this period, mainly in relation to perinatal asphyxia, pulmonary, gastrointestinal and infectious pathology and neonatal mortality.

RESULTS: The presence of MASF complicates 18% of all of our deliveries with it being mild in 10.8%, moderate in 4.4% and severe in 2.8%. Of all newborns with MSAF, one third were admitted to the NCU, mainly for two reasons, association with perinatal asphyxia (124 cases) and observation of a risk of meconium aspiration syndrome (85 cases). The main neonatal morbidities associated with MSAF in our populations were perinatal asphyxia in 56.1% (32 cases of severe perinatal asphyxia and 92 non-severe), pulmonary pathology in 34% (meconium aspiration syndrome in 32 cases and other respiratory abnormalities in 43) and gastrointestinal pathology in 30.5% (transitory feeding intolerance in all cases). Four cases of meconium-stained neonates were exitus. The neonatal morbidity is significantly more frequent in relation to thick meconium and also if perinatal asphyxia is associated to MSAF.

CONCLUSIONS: Although the relationship between MSAF and perinatal asphyxia is controversial, their association increases neonatal morbidity. In accordance with our results, thick meconium is implicated as a risk factor influencing the well being during the intrapartum and postpartum periods.