The association between early glycated hemoglobin (HbA1c) and the risk of neonatal respiratory distress syndrome (NRDS) with preterm premature rupture of membranes (PPROM) population remains largely unknown. The impact of diabetes mellitus (DM) on NRDS is also controversial. HbA1c was assessed in early and late pregnancy. Multivariate logistic regression and restricted cubic spline (RCS) analyses were performed to evaluate the association between the HbA1c and the incidence of NRDS in non-DM group. Propensity score matching (PSM) was performed to balance baseline characteristics between DM group and non-DM group. Among 536 patients with the mean age was 30.7 ± 5.1 years, 117 (21.8%) had DM. The RCS revealed that a linear relationship was found between HbA1c and the incidence of NRDS in non-DM group, with a threshold of approximately 5% (31 mmol/mol). The effect size and CI below and above the threshold value were 1.70 (1.24–2.31) and 1.26 (0.81–1.96), respectively. The ΔHbA1c (late HbA1c minus early HbA1c) was independently associated with incidence of NRDS in DM group. Before and after PSM, no significant association was not observed between DM and the incidence of NRDS. Our findings indicated that higher early HbA1c levels were associated with a risk of NRDS in women without diabetes. Women with diabetes who experience an increase in HbA1c level during pregnancy may be more likely to give birth to infants affected by NRDS.