The study aimed to compare glycemic control and pregnancy outcomes in women with type 1 diabetes mellitus (T1DM) using multiple daily injection therapy (MDI) and continuous subcutaneous insulin infusion (CSII) and to compare outcomes of women treated with long-acting insulin or neutral protamine Hagedorn (NPH). This multicenter prospective cohort study involved women with pregestational T1DM treated with MDI and CSII. Primary outcome was glycated hemoglobin (HbA1c) before and during pregnancy. Secondary outcomes included maternal and neonatal outcomes and quality of life. Of the 121 studied women, the average age was 28.48 years, and the average body mass index was 21.29 kg/m2 at conception and 26.32 kg/m2 at delivery. Of the studied women, 78.51% had planned pregnancy. Women treated with MDI and CSII had comparable HbA1c before pregnancy or in the first and second trimesters. In the third trimester, women on CSII therapy had significantly lower HbA1c (6.07 ± 0.62 vs 6.20 ± 0.88%, p = .017), higher HbA1c on-target rate (71.43% vs 64.62%, p = .030), and greater decline of HbA1c from preconception to the third trimester (-0.65 vs -0.30%, p = .047). Fewer daily insulin requirements were observed in those used CSII compared with MDI-treated women (0.60 ± 0.22 vs 0.73 ± 0.25 U/kg/day, p = .004). Newborns born of mothers treated with the CSII method were more likely to have neonatal jaundice (adjusted odds ratio [OR] 2.76, 95% confidence interval [CI] 1.16-6.57) and neonatal intensive care unit (adjusted OR 3.73, 95%CI 1.24-11.16), and women on CSII had lower scores in patient-reported quality of life (p = .045). In the MDI group, those receiving long-acting insulin had nonsignificant lower HbA1c and higher HbA1c on-target rate in the second and third trimesters, compared with those treated with NPH. Insulin pump users may achieve better glycemic control than multiple daily insulin injections, which did not substantially improve pregnancy outcome.