Aim: To evaluate the effect of faster-acting insulin aspart (faster aspart) vs. insulin aspart (IAsp) on fetal growth and glycemic control in pregnant women with type 1 or type 2 diabetes.

Methods: In a single-center, open-label trial from November 2019 to May 2022 women were stratified by diabetes type and insulin treatment modality (multiple daily injections or insulin pump) and randomized to faster aspart or IAsp from 8 to 13 weeks. Primary outcome was offspring birthweight standard deviation (SD) score. Secondary outcomes included mild hypoglycemia (managed by the woman) in the previous week, HbA1c at inclusion, 21, 33, and 35 weeks, and severe hypoglycemia (requiring third party assistance) reported in a structured interview.

Results: In total, 216 women were included and randomized to faster aspart or IAsp (n=109 vs. n=107). Baseline data were comparable in both groups. Primary outcome data were available in 94% (71% type 1 (of which 19% on insulin pump), 29% type 2 diabetes). Offspring birthweight SD score was median 0.7 (interquartile range -0.3-2.0) vs. 1.1 (0.4-1.9), mean difference -0.2 (95% confidence interval -0.6-0.1), p=0.23 with 41% vs. 46% large for gestational age infants (p=0.39). From randomization to delivery 1 (1%) vs. 7 (7%) women reported severe hypoglycemia (p=0.07) with fewer events reported by women using faster aspart compared to IAsp (1 vs. 10 events, p=0.03). At 33 weeks, women using faster aspart reported fewer mild hypoglycemic events in the previous week compared to IAsp (2.0 (0.8 - 4.0) vs. 3.0 (1.0 - 5.0), p=0.03), while HbA1c was 41 (38-46) vs. 43 (39-46) mmol/mol, p=0.28. Prevalence of preeclampsia was 15% vs. 12% (p=0.51) and preterm delivery <37 weeks 19% vs. 22% (p=0.64). No perinatal deaths were reported.

Conclusion: In pregnant women with type 1 or type 2 diabetes, use of faster aspart resulted in comparable fetal growth and HbA1c with less severe hypoglycemia compared to IAsp.


S.K.Noergaard: Research Support; Novo Nordisk A/S. E.R.Mathiesen: Advisory Panel; Novo Nordisk, Research Support; Novo Nordisk, Speaker's Bureau; Novo Nordisk. K.Nørgaard: Advisory Panel; Medtronic, Novo Nordisk, Research Support; Medtronic, Dexcom, Inc., Novo Nordisk, Zealand Pharma A/S, Speaker's Bureau; Medtronic, Novo Nordisk, Stock/Shareholder; Novo Nordisk. T.D.Clausen: None. J.Søholm: Research Support; Novo Nordisk A/S. P.Holmager: None. N.C.Do: Research Support; Novo Nordisk Foundation. P.Damm: Other Relationship; Novo Nordisk A/S. L.Ringholm: Research Support; Novo Nordisk A/S.


Novo Nordisk A/S (U1111-1209-6358)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at