Diagnosis of cervical incompetency is crucial ; routine cerclage placement is not recommended
1989 Study Abstract
Twenty-three diethylstilbestrol (DES)-exposed patients were evaluated through 27 pregnancies to determine their eligibility for admission to a prospective protocol that combined serial ultrasound surveillance of the lower uterine segment-cervical complex with periodic pelvic examinations to diagnose cervical incompetency.
Of these, 21 pregnant women, including seven vaginectomy patients, were matched to 84 low-risk controls to determine the following:
the effect of DES exposure on reproductive performance,
the efficacy of ultrasound selection of cerclage candidates,
and the influence of previous partial vaginectomy on reproductive outcome.
Five DES-exposed patients were diagnosed as having cervical incompetency and had cerclages placed. There were no missed diagnoses of cervical incompetency. The DES-exposed patients delivered statistically earlier in gestation than did controls (268 +/- 13 versus 276 +/- 10 days). It was not evident that this difference was important clinically, as there were no neonatal deaths, very low birth weight infants, second-trimester losses, or deliveries before 252 days (36 weeks) among the study patients.
Previous vaginectomy did not affect the frequency of the diagnosis of cervical failure or the neonatal outcome. After ultrasound surveillance and treatment for incompetent cervix, a majority of our patients delivered at term without cerclage placement. Therefore, routine cerclage placement is not recommended. Knowledge of the ultrasound criteria for diagnosing cervical incompetency is required.
Sources and more information
Ultrasound surveillance of the cervix during pregnancy in diethylstilbestrol-exposed offspring, Obstetrics and Gynecology 1989 Feb;73(2):230-9., NCBI PMID: 2643065.
Vessey MP, National Center for Biotechnology Information, 1989
1989 Study Abstract
Herbst and his colleagues first showed in 1971 that girls born to mothers who had taken diethylstilbestrol (DES) during pregnancy were at an increased risk of clear-cell adenocarcinoma of the vagina and cervix. At first it was feared that these girls would have a high probability of developing clear-cell carcinomas, but the latest report from the Registry for Research on Hormonal Transplacental Carcinogenesis of the University of Chicago puts the risk at only 1 per 1000 of those exposed, from birth through to age 34.
On this basis, Herbst and his colleagues have suggested that DES is not a complete carcinogen, but that some other factor is involved in the pathogenesis of clear-cell carcinoma of the vagina and cervix.
Women exposed in utero to DES have a high prevalence of vaginal adenosis and tend, therefore, to have an extensive transformation zone on the cervix and in the vagina. There is considerable controversy as to whether or not such women are at increased risk for vaginal and cervical intraepithelial neoplasia.
The latest findings from the Study of the Incidence and Natural History of Genital Tract Anomalies and Cancer in Offspring Exposed in Utero to Synthetic Estrogens (the DESAD project) are, however, worrying; during follow-up, vaginal and cervical intraepithelial neoplasia occurred at a rate of 15.7/1000 woman-years in the exposed and at a rate of 7.9/1000 woman-years in the controls (p = 0.01).
There is some evidence that exposure in utero to exogenous oestrogens increases the risk of testicular cancer in males. The findings, however, are not conclusive, and the effect does not seem to be specific to DES and related nonsteroidal oestrogens.
Sources and more information
Epidemiological studies of the effects of diethylstilboestrol, IARC Sci Publ. 1989;(96):335-48. NCBI PMID: 2680951.
The seminal vesicle of prenatally DES-exposed male mice acquired two key characteristics of female tissues
Previous studies from our laboratory on the feminization of the male mouse reproductive tract after prenatal exposure to Diethylstilbestrol (DES) showed that the mRNA for the major estrogen-inducible uterine secretory protein, lactoferrin (LF), was constitutively expressed in the seminal vesicle of male mice exposed prenatally to DES, but not in the seminal vesicle of control mice. After castration, treatment with 17 beta-estradiol (20 micrograms/kg.day) for 3 days induced the LF mRNA in the seminal vesicle of both control and prenatally DES-exposed mice; however, the levels in DES-treated tissues were approximately 6-fold higher than those in control tissue. This report describes the presence of LF in seminal vesicle tissues and secretions of prenatally DES-exposed mice, as determined by immunohistochemistry and Western blot analysis. Further, these data are correlated with immunolocalization of the estrogen receptor in the seminal vesicle tissue. We conclude that the seminal vesicle of prenatally DES-exposed male mice has acquired two key characteristics of female tissues, namely LF production/regulation and estrogen receptor localization/distribution similar to that in uterine tissues.
Female gene expression in the seminal vesicle of mice after prenatal exposure to diethylstilbestrol, NCBI, PMID: 2707167, 1989 May;124(5):2568-76.