Summary: A new progestational agent, medroxyprogesterone acetate (Provera), has been used in the second and third trimesters of pregnancy in an attempt to prolong gestation and thereby increase foetal salvage. Experience in 89 pregnancies has been recorded. In 21 pregnancies, cervical suture has provided supportive therapy. Sixty‐one surviving infants have resulted from 65 pregnancies in which prolongation was achieved for a significant period of time. The intravenous injection of an aqueous suspension of crystalline Provera has been used in 12 patients. On 6 occasions, where cervical dilatation was less than 3 cm., parturition was postponed. No significant side‐effect, in either mother or infant, has resulted from the use of this synthetic progestational agent.