title: Preterm male infants need more initial respiratory and circulatory support than female infants.
abstract: OBJECTIVE
  The aim of this study was to investigate possible gender-related differences in clinical parameters during the first week of life that could explain the higher morbidity and mortality of preterm male infants.
  
  
  METHODS
  In total, 130 clinical variables were collected from 236 inborn infants (130 male and 106 female infants) with gestational age (GA) < 29 wk. A subgroup of 175 extremely low birthweight infants (ELBW) < 1000 g (n = 86 males; n = 89 females) was analysed separately.
  
  
  RESULTS
  At 6 postnatal h, 60.8% of the male infants needed mechanical ventilation versus 46.2% of the females (p = 0.026). Chronic lung disease (CLD) developed in 36.2% of males versus 9.8% of female infants (p = 0.004). Inotrope support with dopamine was used in more than 50% of the infants; additional inotrope support to dopamine was needed by 19.4% of male and 9.7% of female infants (p = 0.041). The gender-related difference in need for inotrope support was more evident among the ELBW infants; 67.1% of male infants needed inotrope support versus 50.6% of females (p = 0.028). At 12-24 h, male ELBW infants had lower minimum mean arterial blood pressure (mean (SD) 25(4) mmHg vs 28(6) mmHg, p = 0.004)) and lower minimum PaCO2 than females infants (4.3 (1.1) kPa vs 4.7 (0.9) kPa, p = 0.043).
  
  
  CONCLUSIONS
  There are early gender-related differences in need for ventilatory and circulatory support that may contribute to the worse long-term outcome in prematurely born male infants.
authors.affiliation: Department of Paediatrics, Lund University Hospital, Sweden. emma.elsmen@pedi.lu.se
authors.forename: E
authors.initials: E
authors.lastname: Elsmén
authors.forename: I
authors.initials: I
authors.lastname: Hansen Pupp
authors.forename: L
authors.initials: L
authors.lastname: Hellström-Westas
mesh_terms: D001034:Apgar Score; D001724:Birth Weight; D001784:Blood Gas Analysis; D001795:Blood Pressure Determination; D002316:Cardiotonic Agents / Q000008:administration & dosage; D005260:Female; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D012121:Respiration, Artificial / Q000379:methods / Q000706:statistics & numerical data*; D012127:Respiratory Distress Syndrome, Newborn / Q000628:therapy*; D012307:Risk Factors; D012737:Sex Factors; D016896:Treatment Outcome
chemical_list: D002316:Cardiotonic Agents