Effects of nifedipine on spontaneous and methylergometrine-induced activity post partum.

Intrauterine pressure changes were recorded by microtransducer catheter in 17 women immediately post partum. In all patients, spontaneous contractile activity was recorded, characterized by high contraction amplitudes (110 to 350 mm Hg). The calcium entry blocker nifedipine effectively inhibited these contractions. Both in vitro, in strips of pregnant myometrium, and in vivo, methylergometrine induced a contractile activity that could be blocked by nifedipine. The conclusion is that, for the testing of drugs that affect the contractile activity of pregnant myometrium, the use of intrauterine pressure recording by microtransducer catheters in the early postpartum period provides a suitable model.