Teratology study in the mouse using a prostaglandin and a prostaglandin synthetase inhibitor.

Prostaglandin F2 alpha alone and in combination with sodium salicylate, was administered i.m. to pregnant CBA mice at various times on day 9 of gestation. A high frequency of rib malformations (90%) was recorded whereas the resorption rate was moderate (18%). When combining prostaglandin treatment (25 mg/kg i.m.) with sodium salicylate (500 mg/kg i.m.), the resorption rate increased. The malformation frequency remained unchanged except for the group with combined treatment at 10 a.m. (=maximum teratogenic period for salicylate induced rib malformations). This treatment resulted in a high frequency of maternal death; the resorption frequency was 75% and the surviving foetuses were malformed.