Adashi, E. Y., Rock, J. A., Sapp, K. C., Martin, E. J., Wentz, A. C., & Jones, G. S. (1979). Gestational outcome of clomiphene-related conceptions. Fertility and Sterility, 31(6), 620-626. https://doi.org/10.1016/s0015-0282(16)44051-3
Adashi EY, Rock JA, Sapp KC, Martin EJ, Wentz AC, Jones GS. Gestational outcome of clomiphene-related conceptions. Fertil Steril. 1979;31(6):620-626. doi:10.1016/s0015-0282(16)44051-3
Adashi, Eli Y., et al. "Gestational outcome of clomiphene-related conceptions." Fertility and Sterility, vol. 31, no. 6, 1979, pp. 620-626.
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Twins occurred in about 13% of 86 clomiphene-related pregnancies
In a Johns Hopkins nonconcurrent prospective analysis, about 13 out of 100 clomiphene pregnancies (n = 86) produced twins, against 0 out of 100 after ovarian wedge resection (n = 51). The authors found little or no added miscarriage risk against the rate expected in infertile women. Birth defects were not increased against commonly quoted rates for the general population.
Key Findings
Twinning: 12.8% in the clomiphene series and 0% after wedge resection. The study-to-wedge-resection odds ratio was 12.6, and all twin pregnancies were polyzygotic.
Spontaneous abortion: 26.5% in the clomiphene series and 21.6% after wedge resection. The authors reported the difference was not statistically significant.
Birth defects: 3.1% in the clomiphene series (two defects, both in twins) and none after wedge resection.
Perinatal mortality in the clomiphene series was 4.9% and fell to 1.9% when twins were excluded. Three perinatal losses occurred, two of them twins.
Interpretation
The study is a nonconcurrent prospective analysis of 137 chart pairs from one clinic, with follow-up of up to 15 years. The clomiphene group was older and more often white and private patients (non-ward). Twinning was the only outcome that differed significantly between groups. The authors state that sample size precluded meaningful interpretation of ectopic pregnancy, perinatal mortality and birth defect rates.
RRM Context
Clomiphene stimulates ovulation. Restorative reproductive medicine asks why ovulation fails and treats that cause, within an evaluation of both partners. This series reports twinning among pregnancies that followed ovulation induction with clomiphene. The authors report that twinning accounted for most illness and death around birth, and that all birth defects occurred among twins.
Our editorial summary of this paper, not the article's abstract.
Abstract
The experience of the gynecologic endocrinology and infertility clinic at The Johns Hopkins Hospital has been subjected to a nonconcurrent prospective analysis in an attempt to evaluate the gestational fate of clomiphene-related conceptions (study series, n = 86). This latter series was contrasted with a series of pregnancies following bilateral ovarian wedge resection (BOWR) (n = 51) in a comparative analysis of gestational outcome event rates. Post-therapy follow-up was available for varying time spans of up to 15 years. A 12.8% twinning rate constituted the single most important complication of clomiphene therapy, resulting in measurable increments in perinatal morbidity and mortality rates. The observation of a 26.5% spontaneous abortion rate would seem to suggest that clomiphene-related conceptions are at little or more risk for spontaneous abortion than would have been expected from the infertile population under discussion. A 3.1% incidence of post-clomiphene birth defects was not increased as compared with commonly quoted rates for the population at large. The corresponding incidence rates of twinning, spontaneous abortion, and birth defects for the BOWR series were 0%, 21.6%, and 0%, respectively.
