Animal studies revealed a resorption rate that approached 100% when aspirin and dipyridamole were administered together at doses approximately 66 and 2 times, respectively, the maximum recommended daily human dose on a mg/m2 basis. Animal studies with aspirin have revealed evidence of teratogenicity and a high resorption rate (63%) at a dose approximately 44 times that contained in the maximum recommended daily human dose of aspirin-dipyridamole (based on mg/m2). Animal studies with dipyridamole have failed to reveal evidence of fetal harm. Controlled data in human pregnancy exists but cannot establish the absence of risk due to methodological limitations.

AU TGA pregnancy category C: Drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. Accompanying texts should be consulted for further details.

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.

This drug should only be used during the first two trimesters of pregnancy if clearly needed and the benefit outweighs the risk; per some authorities, use is contraindicated during the third trimester of pregnancy.

AU TGA pregnancy category: C
US FDA pregnancy category: Not assigned.

Risk Summary: Available data has not identified a clear association between use of this drug and major birth defects, miscarriage, or adverse maternal or fetal outcomes. Maternal use of high-dose aspirin can result in excessive blood loss at delivery, prolonged gestation, prolonged labor, intracranial hemorrhage in premature infants, low birth weight, stillbirth, and neonatal death.

Comments: If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.

See references

This drug should be used only if clearly needed and the benefit outweighs the risk.

Excreted into human milk: Aspirin: yes; Dipyridamole: yes

Comments:
-Chronic, high-dose maternal aspirin ingestion can cause adverse effects in the breastfed infant.
-The risk of Reye's syndrome from salicylate in breastmilk is unknown.
-Low-dose aspirin (75 to 162 mg daily) may be considered for antiplatelet therapy in breastfeeding women.

Salicylic acid was present in milk at an average concentration of 24 ng/mL in a study of 6 exclusively breastfeeding women who ingested 81 mg of aspirin daily. The calculated relative infant dose was 0.4% based on average milk consumption of 150 mL/kg/day.

See references