Analysis of clinical characteristics and factors associated with short term outcomes in early term neonates

Abstract

Objective: To investigate the clinical characteristics of early term and full term neonates, and analyze the risk factors associated with short term outcomes in early term neonates. Method: Neonates with birth weight (BW) ≥2 500 g from year 2013 were analyzed retrospectively based on American Congress of Obstericians & Gynecologists (ACOG) latest definition of term infants. According to inclusion and exclusion criteria, early term (gestational age 37-38 weeks) and full term(gestational age 39-40 weeks) neonates were included, whose morbidity constituent proportion was analyzed by χ(2) test or Fisher accuracy test or t test or Wilcoxon test. Risk factors associated with short term outcomes in early term population were analyzed by Logistic regression analysis. Result: There were 3 002 discharged term infants being investigated, among whom 1 303 cases were included(768 males and 535 females), and 37, 38, 39 and 40 weeks' gestational age newborns were 160, 324, 450 and 369 respectively. Compared with full term neonates(n=819), early term neonates (n=484) had longer length of hospital stay (LOS)(6.0(5.0, 9.0) vs. 6.0(4.0, 8.0), Z=2.830, P=0.005), higher usage rate of intravenous antibiotics(86.4%(418/484) vs. 80.1%(656/819), χ(2)=8.009, P=0.005), higher assisted ventilation rate(9.5%(46/484) vs. 2.9%(24/819), χ(2)=25.528, P<0.01), higher pulmonary surfactant administration rate(4.3%(21/484) vs. 1.1%(9/819), χ(2)=14.006, P<0.01), as well as higher hypoglycemia incidence(3.9%(19/484) vs. 1.2%(10/819), χ(2)=10.226, P=0.001). There were no statistically significant differences in 1 min Apgar score (9(9, 10)vs. 9(9, 10), Z=0.860, P=0.390), 5 min Apgar score (10(9, 10) vs. 10(9, 10), Z=0.810, P=0.418), white blood cell count (15 (11, 21) ×10(9) /L vs.15 (11, 22) ×10(9) /L, Z=0.880, P=0.379), hemoglobin count(180 (159, 205) vs. 182 (160, 204) g/L, Z=0.560, P=0.576), or platelet count(303(234, 372) ×10(9)/L vs. 301(237, 391) ×10(9)/L, Z=0.550, P=0.584). BW between 2 500 g and 2 999 g(OR 1.69, 95% CI: 1.10-2.62, χ(2) =5.614, P=0.018), wet lung(OR=2.61, 95% CI: 1.61-4.24, χ(2)=15.023, P=0.000)and pneumonia(OR 1.88, 95% CI: 1.14-3.08, χ(2)=6.192, P=0.013) were risk factors in early term neonates' short term adverse outcomes. Conclusion: Early term newborns are still at their "immature" state, and respiratory disorders are major risk factors associated with short term outcomes. Hence, early delivery during 37-38 weeks should be avoided as possible as we can.