Double blind trial of ritodrine and placebo in twin pregnancy.
O'Connor M C, Murphy H, Dalrymple I J·British journal of obstetrics and gynaecology
In a double blind trial, 25 patients with twin pregnancy were given 40 mg of ritodrine hydrochloride by mouth daily and 24 similar patients received a placebo. The ritodrine group had no significant prolongation of pregnancy nor increase in birth weight, and a high incidence of side effects occurred.