Effects of gender on incidence of intraventricular hemorrhage in very low and extremely low birth weight infants

Abstract

Objective To examine the relationship between gender and intraventricular hemorrhage (IVH) in very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI).Methods From January 1,1999 to December 31,2012,data on VLBWI and ELBWI,who were admitted to the neonatal intensive care unit of Yuying Children's Hospital within 14 d after birth,were retrospectively collected.The Chi-square test and t test were used to compare neonatal outcomes between male and female infants.The Logistic model was used to analyze the risk factors for IVH.Results A total of 1 008 cases were enrolled,including 615 males and 393 females,895 VLBWI and 113 ELBWI.The incidence of IVH was 15.1％ (152/1 008) and the incidence of severe IVH was 8.4％ (85/1 008).Compared with females,males had a higher total incidence of IVH [17.2％ (106/615) vs 11.7％ (46/393),x2=5.728,P＜0.05] and severe IVH [9.8％ (60/615) vs 6.4％ (25/393),x2=3.896,P＜0.05].These differences were also seen in VLBWI with a birth weight of 1 250 to 1 499 g [IVH:13.7％ (47/344) vs 7.8％ (17/217),x2=4.473,P=0.034; severe IVH:7.6％ (26/344) vs 2.8％ (6/217),x2=5.684,P=0.017].Logistic regression analysis showed that the risk factors for IVH were as follows:gestational age ＜28 weeks (aOR=2.012,95％CI:1.288-3.143,P＜0.05),neonatal respiratory distress syndrome (aOR=l.584,95％CI:1.007-2.492,P＜0.05),invasive mechanical ventilation (aOR=2.743,95％CI:1.826-4.121,P＜0.05),electrolyte disturbance (aOR=2.128,95％CI:1.092-4.149,P＜0.05) and periventricular leukomalacia (aOR=2.901,95％CI:1.312-6.416,P＜0.05),but not male sex (aOR=1.351,95％CI:0.917-1.991,P=0.128).The risk factors for severe IVH were gestational age ＜28 weeks (aOR=2.200,95％CI:1.305-3.708,P＜0.05),invasive mechanical ventilation (aOR=4.714,95％CI:2.809-7.911,P＜0.05) and electrolyte disturbance (aOR=2.232,95％CI:1.047 4.759,P＜0.05),but not male sex (aOR=1.361,95％CI:0.823 2.252,P=0.247).Conclusions Male VLBWI and ELBWI have a higher incidence of IVH and severe IVH,but male sex is not a risk factor for IVH or severe IVH. Key words: Cerebral hemorrhage; Cerebral ventricles; Infant, very low birth weight; Infant, extremely low birth weight; Sex factors