Effect of stilbestrol on pregnancy compared to the effect of a placebo

Compared to a placebo, there was no benefit with the use of stilbestrol in preventing miscarriages.


Effect of stilbestrol on pregnancy compared to the effect of a placebo, American journal of obstetrics and gynecology, Volume 65, Issue 3, Pages 592–601 0002-9378(83)90615-4, March 1953.

One hundred ninety pregnant women received increasing doses of stilbestrol. Treatment was begun by at least the twentieth week of pregnancy and continued through the thirty-fifth week of pregnancy, unless the patient delivered or aborted while on the treatment. The dose of stilbestrol began with 6.3 mg. to 50 mg. a day and ended with 137.5 mg. a day.

Two hundred three similar women received an indistinguishable placebo and provided a fair comparison.

The stilbestrol had no effect on :

  • pre-eclampsia,
  • prematurity,
  • fetal weight and survival,
  • or the size of the placenta.

The importance of adequate controls is discussed.


All interventions need objective evidence of effectiveness and possible placebo effect should not be ignored. Antenatal oestrogen (stilbestrol) was not shown to be of benefit in preventing adverse fetal outcome. The miscarriage rate, preterm labour, birthweight, stillbirth or neonatal death were not positively influenced by the intervention as compared to the control group.

Another researcher presented his prospective placebo controlled trial in an annual meeting of the American Gynecological Society in 1953, the result of which contradicts Smith’s 1948 theory. The DES tragedy buttress the need for adequate and rigorous research into the use of drugs in pregnancy and ensure that they do more good than harm before being introduced for consumption.

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