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Insulin aspart Pregnancy and Breastfeeding Warnings

Medically reviewed by Last updated on Mar 28, 2022.

Insulin aspart is also known as: Fiasp, NovoLog FlexPen, NovoLog PenFill, Novolog, ReliOn NovoLog

Insulin aspart Pregnancy Warnings

In pregnant rats and rabbits, insulin administration at doses 8 times the recommended human dose did not cause adverse developmental effects. Pre- and post-implantation losses and visceral/skeletal abnormalities were seen at higher exposures, which were considered secondary to maternal hypoglycemia. Pregnancies complicated by hyperglycemia pose an increased risk of birth defects, pregnancy loss, or other adverse events. The estimated background risk of major birth defects in women with pre-gestational diabetes and a HbA1c less than 7% is 6% to 10% compared with 20% to 25% in women with a HbA1c greater than 10%. Compared to human insulin, differences in adverse effects or health of the fetus have not been shown with insulin aspart. Patients with diabetes or a history of gestational diabetes should maintain good metabolic control before conception and during pregnancy. During pregnancy, insulin requirements may decrease during the first trimester; increase during the second and third trimesters, and rapidly decline after delivery.

AU TGA pregnancy category A: Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

Use is considered acceptable

AU TGA pregnancy category: A
US FDA pregnancy category: Not assigned

Risk Summary: Available data have not reported an association with insulin aspart and major birth defects or adverse maternal or fetal outcomes, specifically during the second trimester of pregnancy; there are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy.

Comment: For women who are pregnant, and for women who are contemplating pregnancy, intensified blood glucose control and close monitoring of blood glucose is essential.

See references

Insulin aspart Breastfeeding Warnings

Exogenous insulins, including the newer biosynthetic insulins (i.e. aspart, detemir, glargine, glulisine, lispro) appear to be excreted into breast milk. Insulin is a protein that is inactivated if taken by mouth. If absorbed, it would be destroyed in the digestive tract of the infant.

Lactation onset occurs later in women with type 1 diabetes, and there is an even greater delay in those with poor glucose control. However, once established lactation persists as long in mothers with diabetes as in mothers without. Insulin requirements are generally lower in women who breastfeed, most likely due to glucose being used for milk production.

Use is considered acceptable

Excreted into human milk: Yes

Comments: Women with diabetes who are breastfeeding may require adjustments of their insulin dose.

See references

References for pregnancy information

  1. "Product Information. NovoLOG (insulin aspart)." Novo Nordisk Pharmaceuticals Inc (2022):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. "Product Information. Fiasp (insulin aspart)." Novo Nordisk Pharmaceuticals Inc (2017):

References for breastfeeding information

  1. "Product Information. NovoLOG (insulin aspart)." Novo Nordisk Pharmaceuticals Inc (2022):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. United States National Library of Medicine "Toxnet. Toxicology Data Network." (2013):
  5. "Product Information. Fiasp (insulin aspart)." Novo Nordisk Pharmaceuticals Inc (2017):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.