Objective To compare the hospitalization outcomes of 34 weeks or over preterm infants with preterm premature rupture of membranes (PPROM) in obese and non-obese pregnant women. Methods A retrospective analysis of PPROM preterm infants born in our hospital and admitted to the neonatology department from January 2016 to December 2020 with a gestational age of 34 weeks or over was carried out. According to the pregnant women's body mass index (BMI) at delivery, they were divided into obese group (BMI≥30 kg/m²) and non-obese group (BMI<30 kg/m²). The general conditions, pregnancy outcomes and late premature infants hospitalization outcomes between the two groups were compared using two independent samples t test and χ² test. Results Compared with non-obese pregnant women, the incidence of respiratory complications after delivery in late preterm infants of obese pregnant women was higher, mainly manifested as high incidence of neonatal respiratory distress syndrome, assisted ventilation, oxygen inhalation and the use of surfactants, sepsis, and pneumonia, also maternal gestational diabetes incidence was increased, and the differences were statistically significant (P<0.05); other complications of neonatal hyperbilirubinemia, necrotizing enterocolitis, intraventricular hemorrhage, bronchopulmonary dysplasia were not statistically significant (P>0.05). Conclusions Compared with non-obese pregnant women with 34 weeks or over PPROM, obese pregnant women had an increased incidence of adverse outcomes in late preterm infants such as respiratory complications and sepsis.