Letter: Ectopic pregnancy after postcoital diethylstilbestrol

Letter 1

The report of Drs. A. R. Smythe II and P. B. Underwood, Jr., attributes the ocurrence of a tubal pregnancy to failure of high doses of postcoital stilbestrol to prevent pregnancy. This assumption is almost certainly erroneous. In a series of papers, my associates and I presented irrefutable evidence, including basal body temperature charts taken during cycles of fertilization, which indicated that ectopic conception with few exceptions precedes, not follows, the patient’s last recorded menstrual period. In other words, at the time of the “condom accident,” in the authors’ reported case, on Day 14 of the cycle the patient must have been pregnant for about three weeks.

Significantly. all previously reported “method failures” with diethylstilbestrol that had been reviewed by the authors had apparently resulted in ectopic gestation. In view of current knowledge concerning the pathologic mechanism of extrauterine pregnancies, this observation indicates that the drug, if given in adequate doses and at the appropriate time, invariably prevents pregnancy.

The association of ovulation defects and their accompanying phenomena with various pathologic conditions of gestation is a very interesting problem that has been in the center of interest of prominent reproductive biologists in recent years. Therefore, it is unfortunate that obstetricians continue to ignore the relevant data despite their considerable academic and clinical significance.
Leslie Iffy, M.D.

Letter 2

In reply to Dr. Iffy’s letter regarding ectopic pregnancies after postcoital diethylstilhestrol, I disagree with both of his points. The duration of time from this patient’s last menstrual period until a positive pregnancy test was seven weeks and five days and exactly nine weeks until the time of tubal rupture. From Dr. Iffy’s theory, she would have been 13 weeks pregnant. The abortion was a tubal abortion with an intact tubal serosa and no grossly recognizable fetus.

I do agree that a woman may have normal menses with a developing tubal pregnancy but certainly not always. In this patient, the condom accident was followed in the proper time sequence by missed menses, symptoms of pregnancy, a positive pregnancy test, and then the tubal abortion. For these reasons, I believe that the date of nine weeks from the last menstrual period is the more accurate gestational age.

As for Dr. Iffy’s second point that stilbestrol invariably prevents pregnancy, evidence strongly opposes this, as illustrated in this case and the review of the 9,000 exposures reported by Dr. John Morris as referred to in the original manuscript. I do agree that a Pearl index of 0.4 indicates a highly successful means of preventing pregnancy.

I appreciate the opportunity to answer Dr. Iffy’s letter and regret that I disagree with him; however, disagreements usually enlighten all parties involved and make medicine a challenging frontier.
Paul B. Underwood, Jr., M.D.


  • Letter: Ectopic pregnancy after postcoital diethylstilbestrol, American journal of obstetrics and gynecology, PMID: 937419, 1976 July.
  • Image credit Anthony Tran.

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