Preterm birth after mature fetal lung indices: is there any neonatal morbidity?

Neonatal morbidity occurs despite pulmonary maturity prior to 39 weeks gestation

OBJECTIVE

To compare outcomes among late-preterm or early-term neonates according to fetal lung maturity (FLM) status.

STUDY DESIGN

We conducted a retrospective cohort study of 234 eligible singletons delivered after FLM testing before 39 weeks gestation at our center over a 2-year time period. A primary composite neonatal outcome included death and major morbidities.

RESULT

The overall rate of primary composite morbidity was 25/46 (52.2%) and 61/188 (32.4%) in the immature/transitional and mature groups, respectively. After adjustment for confounders including gestational age, the composite outcome was not significantly different; adjusted odds ratio (aOR)=1.4 (confidence interval (CI)=0.7-3.0). The rate of respiratory distress syndrome was significantly higher in the immature/transitional group; odds ratio=3.4 (CI=1.1-10.3) as expected.

CONCLUSION

FLM status did not correlate with the spectrum of neonatal morbidities in late-preterm and early-term births. Neonatal complications remained common in both groups.

Effect of heavy metals in the meconium on preterm mortality: preliminary study

BACKGROUND

There have been many studies that have investigated the risk factors of mortality in preterm infants, but none has shown an association between preterm mortality and exposure to heavy metals or trace elements. The aim of this study was therefore to measure the levels of toxic metals (lead, cadmium) and trace elements (zinc, iron, copper) in meconium samples and elucidate their association with preterm mortality.

METHODS

Metals and trace elements were measured in the meconium of 304 preterm infants using a flame atomic absorption spectrophotometer.

RESULTS

The level of heavy metals and trace elements in non-surviving infants was significantly higher than in surviving infants. Moreover, the level of heavy metals and trace elements in non-surviving infants whose gestational age was <30 weeks (n = 11) was significantly higher than in surviving infants (n = 12). Receiver operating characteristic curve analysis showed that gestational age and meconium lead level predicted early mortality in premature newborns. Furthermore, this curve analysis showed that, when comparing meconium lead level and gestational age, meconium lead level had a similar effect on mortality as gestational age.

CONCLUSION

Meconium lead level and gestational age are associated with increased mortality risk in preterm neonates.

Neonatal morbidity after documented fetal lung maturity in late preterm and early term infants

OBJECTIVE

Fetal lung maturity often is used as the sole criterion that late preterm infants are ready for postnatal life. We therefore tested the hypothesis that fetal lung maturity testing does not predict the absence of morbidity in late preterm infants.

STUDY DESIGN

We performed a retrospective cohort study to examine 152 infants who were born in the late preterm (34 0/7 to 36 6/7 weeks) and early term (37 0/7 to 38 6/7 weeks) periods after mature fetal lung indices and compared them with 262 infants who were born at ≥39 weeks' gestation and who were matched by mode of delivery.

RESULTS

Despite documented fetal lung maturity, infants who were born at <39 weeks had significantly higher rates of neonatal morbidities compared with infants who were born at ≥39 weeks' gestation. After adjustment for significant covariates, we found that infants who were born at <39 weeks' gestation had an increased risk of composite adverse outcome (odds ratio, 3.66; 95% confidence interval, 1.48-9.09; P < .01).

CONCLUSION

Fetal lung maturity testing is insufficient to determine an infant's readiness for postnatal life.