Menstrual and reproductive characteristics of women whose mothers were exposed in utero to diethylstilbestrol (DES), International journal of epidemiology, NCBI PubMed PMID: 16723367, 2006 Aug.
Full text: Oxford Journals, Medicine & Health, International Journal of Epidemiology, Volume 35, Issue 4Pp. 862-868, doi: 10.1093/ije/dyl106, August 2006.
In women, prenatal exposure to diethylstilbestrol (DES) is associated with adult reproductive dysfunction. The mouse model, which replicates many DES outcomes, suggests DES causes epigenetic alterations, which are transmissable to daughters of prenatally exposed animals. We report menstrual and reproductive characteristics in a unique cohort comprising daughters of women exposed prenatally to DES.
Menstrual and reproductive outcomes and baseline characteristics were assessed by mailed questionnaire in 793 women whose mothers had documented information regarding in utero DES exposure.
Mean age at menarche was 12.6 years in both groups,
- but daughters of the exposed women attained menstrual regularization later (mean age of 16.2 years vs. 15.8 years; P = 0.05),
- and were more likely to report irregular menstrual periods, odds ratio (OR) = 1.54 [95% confidence interval (95% CI 1.02–2.32)].
A possible association between mothers’ DES exposure and daughters’ infertility was compatible with chance, age, and cohort adjusted OR = 2.19 (95% CI 0.95–5.07). We found limited evidence that daughters of the exposed had more adverse reproductive outcomes, but daughters of exposed women had fewer live births (1.6) than the unexposed (1.9) (P = 0.005).
The high risk of reproductive dysfunction seen in women exposed to DES in utero was not observed in their daughters, but most women in our cohort have not yet attempted to start their families, and further follow-up is needed to assess their reproductive health. Our findings of menstrual irregularity and possible infertility in third-generation women are preliminary but compatible with speculation regarding transgenerational transmission of DES-related epigenetic alterations in humans.
Excerpts and Discussion
The mean birth weight of offspring appeared lower in daughters of the exposed than in the unexposed (3374.2 g vs. 3540.5 g) (P = 0.08).
Our data indicate that DES Grand Daughters attain menstrual regularity at a slightly later age than daughters of the unexposed and are more likely to experience menstrual irregularity.
Our study suggests that infertility may also be more frequent in the DES Grand Daughters, and that DES exposure may exacerbate age-related infertility, a possibility compatible with findings in men who were exposed to DES in utero. The proportion of third-generation women affected by infertility (5%) in this study was far lower than that observed in the (second) generation of women exposed in utero to DES (30%).
In the prenatally exposed women, infertility is primarily due to anatomic anomalies of the uterus or fallopian tubes; other diagnoses, including hormonal/ovulatory problems, play a less striking role. Anatomic and tissue anomalies were not observed in a study of 28 third-generation women, but the number of participants was too small to rule out a low prevalence, and some irregularities (e.g. uterine, tubal) might not be evident on physical examination.
Further follow-up is needed to confirm the possible infertility in the third-generation women, and to evaluate specific diagnoses, which may provide insight into DES-related mechanisms.
It is well-known that women exposed to DES in utero have increased pregnancy complications and adverse birth outcomes, including ectopic pregnancy, pregnancy loss, and preterm delivery. Our data are not conclusive regarding adverse pregnancy outcomes in third-generation women, although daughters of the exposed had somewhat fewer live born children and babies of slightly lower average birth weight. Further follow-up will be essential to assess reproductive outcomes as more of the third-generation women enter their reproductive years.
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