Analysis on perinatal risk factors and clinical characteristics of complications in early term infants

Abstract

Objective To explore the perinatal risk factors and clinical characteristics of complications of early term neonates. Methods Data of 5 468 live term newborns and their mothers hospitalized in the Third Affiliated Hospital of Zhengzhou University from January 2013 to December 2013 were analyzed. Background information, morbidity and complications of the mothers were compared among early, full and late term groups (n=1 933, 3 013, 412, respectively). And background information and incidence of complications were also investigated among neonates of early, full and late term groups (n=2 033, 3 023, 412, respectively), and neonates born between 37-37+6 (n=695) and 38-38+6 weeks (n=1 338). One-way analysis of variance, LSD-t test, logistic regression analysis, Chi-square or Fisher exact test, Pearson Chi-square test, corrected Chi-square test were used for statistical analysis. Results 1. Comparison among the early, full and late term group showed that higher proportions of elder gravida [21.1%(407/1 933), 10.5%(317/3 013), 6.8%(28/412), χ2=127.690], multipara [43.7%(844/1 933), 23.1%(697/3 013), 15.0%(62/412), χ2=287.765], scarred uterus [27.9%(539/1 933), 8.9%(267/3013), 1.5%(6/412), χ2=396.521], higher incidence of cesarean section [75.2%(1 453/1 933), 56.2%(1 693/3 013), 54.1%(223/412), χ2=196.348], hypertensive disorder complicating pregnancy [9.2%(178/1 933), 3.5%(105/3 013), 2.9%(12/412), χ2=79.915], multiple pregnancy[5.1%(99/1 933), 0.3%(9/3 013), 0.0%(0/412), χ2=147.860], gravidity>1[63.1%(1 220/1 933), 47.3%(1 425/3 013), 39.6%(163/412), χ2=147.668], premature rupture of fetal membranes[20.6%(398/1 933), 14.2%(428/3 013), 10.2%(42/412), χ2=47.217], abnormal amniotic fluid[17.8%(344/1 933), 12.3%(370/3 013), 11.2%(46/412), χ2=32.777], gestational diabetes mellitus[11.5%(223/1 933), 5.9%(178/3 013), 5.1%(21/412), χ2=56.169], abnormal presentation [9.5%(184/1 933), 5.1%(155/3 013), 2.9%(12/412), χ2=43.511], abnormal placenta [7.6%(146/1 933), 3.1%(92/3 013), 2.7%(11/412), χ2=57.739], hysteromyoma[4.9%(94/1 933), 2.3%(68/3 013), 0.7%(3/412), χ2=35.062] in the early term group than in the full and late term group, respectively ( all P<0.016). Multivariate logistic analysis showed that multiple pregnancy (OR=21.736, 95%CI: 10.785-43.806),scarred uterus (OR=3.302, 95%CI: 2.679-4.071) and hypertensive disorder complicating pregnancy(OR=2.658, 95%CI: 2.040-3.465) were the leading three perinatal risk factors for early term delivery. 2. The incidence of the following neonatal conditions were different among early, full and late term infants (all P<0.05): hyperbilirubinemia [12.5%(255/2 033), 3.9%(119/3 023), 4.9%(20/412), χ2=138.343], infectious diseases [4.3%(88/2 033), 2.0%(59/3 023), 1.7%(7/412), χ2=27.122], asphyxia[3.0%(60/2 033, 1.4%(42/3 023), 1.0%(4/412), χ2=17.795], brain damage [2.3%(46/2 033), 0.5%(15/3,023), 10.%(4/412)], respiratory distress syndrome [1.1%(23/2 033), 0.2%(7/3 023), 0.0%(0/412)], feeding problems [2.0%(41/2 033), 0.3%(10/3 023), 1.0% (4/412) ], surgical diseases[2.0%(41/2 033), 0.9%(28/3 023), 1.5%(6/412), χ2=0.709], intracranial hemorrhage [1.9%(39/2 033), 0.9%(26/3 023), 0.5%(2/412) , χ2=13.263], wet lung [0.9%(19/2 033), 0.4%(11/3 023), 0.5%(2/412)]. Incidences of the above complications in the early term infants were all higher than in the full term infants, but when compared with the later term infants, only that of hyperbilirubinemia and infectious diseases was higher (all P<0.016). Incidence of admission ot NICU [24.5%(170/695) vs 11.5%(153/1 338), χ2=57.729], hyperbilirubinemia [19.0%(132/695) vs 9.2%(123/1 338), χ2=40.046], infectious diseases[6.2%(43/695) vs 3.4%(45/1 338), χ2=8.807], brain damage[4.0%(28/695) vs 1.3%(18/1 338), χ2=14.828], and NRDS[2.0%(14/695) vs 0.5%(9/1 338), χ2=7.329], feeding problems [3.2%(22/695) vs 1.5%(20/1 338), χ2=6.271], intracranial hemorrhage [3.2%(22/695) vs 1.3%(17/1 338), χ2=8.684], wet lung [1.7%(12/695) vs 0.5%(7/1 338), χ2=7.049] of the early term infants born at 37-37+6 weeks were all higher than those born at 38-38+6 weeks(all P<0.05). Conclusions Multiple pregnancy, scarred uterus and hypertensive disorder of pregnancy are the three leading perinatal risk factors of early term delivery. The incidence of neonatal complications among early term infants are higher than those among full term infants, and early term infants are more likely to stay in NICU. We should take preventive measures to decrease the rate of early term delivery and improve the follow-up management of early term infants. Key words: Infant, newborn; Infant, premature; Peripartum period; Risk factors; Intensive care units, neonatal; Infant mortality