The side effects of cesarean with the increasing rate section began to attract the attention of pediatricians in recent years. Previous studies reported that the incidence of neonatal pnermothorax by full-term cesarean section, especially selective cesarean section, was significantly higher than vaginal birth or non-selective cesarean section. In addition, with an extensive establishment of NICUs in China and widely use of mechanical ventilation, the rate of successful neonatal rescue was improved obviously, but the incidence of pneumothorax was increasing. Studies suggested that the incidence of neonatal iatrogenic pneumothorax was highly relevant with selective cesarean section and mechanical ventilation. The indications for cesarean section and mechanical ventilation should be carefully considered.

Objective To investigate the cerebral haemodynamics change and morbidity of periventricular-intraventricular hemorrhages(PIVH) in premature infants with or without patent ductus ateriosus (PDA).Methods Bedside Echocardiography and transcranial sonography (TCS) were performed on 85 cases of preterm infants in 48 h,48 to 96 h,96 to 120 h,120 to 168 h after birth (gestational age≤34 weeks and birth weight≤2 000 g).PDA,peak systolic velocity (Vs),end-diastolic velocity (Vd),pulsatility index (PI) and resistant index (RI) of anterior and middle cerebral artery(ACA and MCA) and PIVH were monitored simutaneously.Results According to the Echocardiography and clinical symptoms,all the cases were divided into 3 groups:haemodynamic significant PDA group (hsPDA group,n =23),non-hsPDA group(nhsPDA group,n =38) and non-PDA group(nPDA group,n =24).The mean birth weight and gestational age did not differ significantly among the 3 groups.Single and multiple Logistic analysis indicated that invasive mechanical ventilation less than 48 h after birth was related to hsPDA (x2 =11.182,P =0.019; OR =10.06,P =0.039).Repetitive measurement deviation analysis found that:Vd of ACA and MCA were lower in the hsPDA group than those in the nhsPDA group (P =0.000,P =0.001) and the nPDA group (P =0.003,P =0.013),while PI and RI were higher than in the other 2 groups.Compared with non-closed group,at 7 days after birth in hsPDA group,RI and PI of closed group were significantly lower,while Vd was significantly higher.Nevertheless,there was no significant difference in hemodynamic parameters when comparison with nPDA group at 7 days after birth.There was no statistical difference in the grading and severity of PIVH with or without PDA.However,the rate of severe PIVH was found higher in hsPDA group than the other 2 groups(17.39％ vs 8.33％ vs 5.26％,x2 =2.405,P =0.280).Conclusions The invasive mechanical ventilation less than 48 h after birth was probably associated with preterm hsPDA.HsPDA could result in major cerebral haemodynamic changes and increase the morbidity of severe PIVH.