Acute respiratory distress syndrome in neonates has been defined in 2015. Earlier identification and successful intervention into the potential pregnancy associated risk factors for the conversion from NRDS to ARDS is one of the most important components of ARDS prevention.

Pregnancy risk factors (PRF), such as intrahepatic cholestasis during pregnancy(ICP), hypertensive disorder complicating pregnancy(HDCP) and gestational diabetes mellitus(GDM), are related to NRDS, ARDS and subsequent death. Meantime, it has also been proven that the prevention of PRF reduces the risk of NRDS and ARDS. However, few study reported the relations between PRF and the conversion from NRDS to ARDS, and it also remains unknown whether treating PRF can reduce the progression from NRDS to ARDS.

We have found that PRF were related to the increase and deterioration of NRDS in a Chinese cohort. The aims of the present study were: 1). to report the effects of PRF on the conversion from NRDS to ARDS. 2). to clarify whether PRF treatment could prevention from conversion from NRDS to ARDS in a Chinese population.

Inclusion Criteria:

1. The gestational age was less than 37 weeks;
2. These neonates were diagnosed with NRDS; The diagnosis of NRDS was based on clinical manifestations and chest X-ray findings. The clinical signs and symptoms of NRDS were respiratory distress, tachypnea, nasal flaring, groan, and cyanosis after birth. The typical X-ray picture of RDS showed a grain shadow, air bronchogram or white lung.
3. informed parental consent has been obtained

Exclusion Criteria:

1. parents' decision not to participate;
2. major congenital anomalies;
3. died or left the neonatal intensive care unit(NICU) within 24 hour.

The gestational age was less than 37 weeks;