[Assessment of fetal maturity in high risk pregnancies: analysis according to gestational age]

To study, in high risk pregnancies, the results of fetal maturity evaluation, and analyze the perinatal results.

Between July 1998 and August 1999, 180 amniocentesis were performed at the Fetal Surveillance Unit to assess fetal maturity. The amniotic fluid exams included Shake Test and orange cells counting. The perinatal results were correlated to fetal maturity in the 75 cases that delivery occurred until 7 days after the amniotic fluid analysis.

The macroscopic aspects showed 91% of clear amniotic fluid 33% of hemorragic, and 3.3% of meconial fluid. The fetal maturity was evidenced at 28% of analyzed exams. When the fetus was immature, 13% of newborn required artificial ventilation at birth and 65% were allocated at the neonatal intensive care unit. Between the mature fetuses, only one (2.5%) required artificial ventilation at birth and 10% were allocated at the neonatal intensive care unit (p<0.05).

The fetal maturity was associated to less newborn interventions. Between the 29th and 32nd weeks 10% of amniotic fluid analysis showed maturity, providing that, when necessary, the amniotic fluid sample study can be performed at these periods. No cases of fetal maturity were diagnosed before 29th week.