Adverse effects on the reproductive tract in male and female DES progeny

In utero exposure to diethylstilbestrol: Adverse effects on the reproductive tract and reproductive performance in male and female offspring, 1982


Exposure to diethylstilbestrol (DES) in utero is associated with adverse effects on the reproductive tract in male and female progeny.

  • These effects include epididymal cysts, microphallus, cryptorchidism, and testicular hypoplasia in male subjects
  • and adenosis, clear cell adenocarcinoma, and structural defects of the cervix, vagina, uterus, and fallopian tubes in female subjects.

As these offspring have reached reproductive age, reports of adverse reproductive performance have been published, including still controversial reports of menstrual dysfunction and infertility.

More well established are increased rates of spontaneous abortion, ectopic pregnancy, premature deliveries, and perinatal deaths, all contributing to an increase in overall adverse pregnancy outcome.

Often there is correlation between the DES-associated anatomic abnormalities in the reproductive tract and the adverse reproductive performance.

Altered male reproductive capacity is also suggested by diminished semen analyses and sperm penetration assays.

A detailed review of these effects of in utero DES exposure is presented.


  • In utero exposure to diethylstilbestrol: Adverse effects on the reproductive tract and reproductive performance in male and female offspring, American journal of obstetrics and gynecology, NCBI PubMed, PMID: 6121486, 1982 Apr 1.
  • Featured image credit isaac cabezas.

DES immunotoxicity

The comparative immunotoxicity of five selected compounds following developmental or adult exposure, 2006

Study Abstract

It is well established that human diseases associated with abnormal immune function, including some common infectious diseases and asthma, are considerably more prevalent at younger ages. Although not established absolutely, it is generally believed that development constitutes a period of increased immune system susceptibility to xenobiotics, since adverse effects may occur at lower doses and/or immunomodulation may be more persistent, thus increasing the relative risk of xenobiotic exposure to the immunologically immature organism.

To address this issue, a brief overview of immune maturation in humans is provided to demonstrate that functional immaturity alone predisposes the young to infection. Age-dependent differences in the immunotoxic effects of five diverse compounds, diethylstilbestrol (DES), diazepam (DZP), lead (Pb), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and tributyltin oxide (TBTO), which have undergone adult and developmental immunotoxicity testing in rodents, are then reviewed, as are human data when available. For all five chemicals, the developing immune system was found to be at greater risk than that of the adult, either because lower doses produced immunotoxicity, adverse effects were more persistent, or both.

Diethylstilbestrol immunotoxicity


Between 5 and 10 million pregnant women were given diethylstilbestrol (DES), a potent synthetic nonsteroidal estrogen, between 1938 and 1971 to prevent premature delivery or pregnancy loss. Its use was terminated when a rare form of reproductive system cancer was found in female offspring of DES-exposed mothers. Male and female reproductive systems malformations have been reported in children of treated women, as has anecdotal evidence of immune system dysfunction. DES was also used to increase weight gain in livestock, although this use is no longer permitted in most countries.

Effects on the Immune System in Humans

Both female and male children of DES-exposed mothers report a higher incidence of autoimmune diseases and asthma (Baird et al., 1996). In general, these diseases are considered to be the result of inappropriate immune system responses, or possible loss of homeostatic control, instead of immune system suppression.

Effects on the Immune System in Rodents

In utero exposure
Luster et al. (1978b) reported that a single injection of 0.1 mg DES/kg body weight on gestational day (GD) 16 did not affect the antibody response to the T-cell-dependent antigen, sheep red blood cells (SRBC), when evaluated in 7-wk-old male and female offspring of Swiss-Webster mice. The T-independent IgM response of female offspring to bacterial lipopolysaccharide (LPS) was suppressed by DES, but was similar to control responses when females were
immunized for a second time. In marked contrast, the male offspring response to LPS immunization was enhanced after both first and second immunizations, an effect attributed to the stimulating effect of estrogen on the antibody response to LPS. Delayed-type hypersensitivity responses (DTH) were suppressed in female, but not in male, offspring, even though thymus weights and T-cell responses to polyclonal stimulation were suppressed in both genders (Luster et al., 1979). Further studies suggest that DES targets early precursors of T lymphocytes in the fetal liver, accounting for thymic atrophy and suppression of DTH (Holladay et al., 1993), but not for defects in T-independent responses to LPS of female offspring.

Neonatal exposure
Nonspecific T- and B-cell proliferation was reported to be suppressed in 6-wk-old female NMRI mice given 5 μg DES/d (roughly 2.2 mg DES/kg/d) over postnatal days (PND) 1–5 (Kalland et al., 1979); suppression was still evident at 17 mo of age (normal life span ~24 mo). It is noteworthy that neither estradiol nor corticosterone exposure over PND 1–5 produced long-term suppression, and that lymphocyte proliferation was comparable to control values at 6 wk of age in females exposed to DES over PND 6–10. Lower doses (approximately 4.4, 44, or 440 μg/kg/ d) had no effect on proliferative response. The 5-μg DES/d exposure regimen also decreased NK cell activity in 6- to 8-wk-old female inbred C57Bl/6 (75%↓) and BALB/c (53%↓) mice and in outbred NMRI (28%↓) mice (Kalland, 1980a). NMRI or AKR/J female mice, exposed to 5 μg DES/d over PND 1–5, were also more likely to develop tumors after low dose injection of a known carcinogen (Kalland & Forsberg, 1981). A subsequent paper (Kalland, 1984) reported that, on a per cell basis, NK cells from DES mice were as active as cells from the control group, but that exposure reduced the number of NK cell precursors in the bone marrow. In other words, NK cells from experimental animals were as efficient as those from controls, but a deficiency in NK cell precursors produced functional suppression of NK activity at the whole animal level. The same postnatal exposure regimen (Kalland, 1980a) reduced the T-lymphocyte-dependent antibody response to SRBC by ~60%, and the T-independent response to bacterial LPS by ~40% when examined in 16- to 18-wk-old NMRI mice. Suppression of the T-dependent response was reportedly due to a defect in T-helper cells. DTH responses were likewise suppressed in 6- and 9-mo-old NMRI females exposed to approximately 2.2 mg/kg/d over PND 1–5 (Kalland & Forsberg, 1978). Kalland (1980b) also reported a persistent (at least 6.5 mo postpartum) decrease in the proportion of T cells in the spleens of DES-exposed mice.

Adult exposure
Luster et al. (1980) reported suppression of the antibody response to SRBC or LPS, and the DTH to keyhole limpet hemocyanin (KLH), in adult female mice exposed to 2 or 8 mg DES/kg/d × 5 d. The DTH was decreased in mice dosed with DES after, but not before, sensitization with KLH, suggesting that the suppressive effects of DES on DTH were not persistent. Using the same exposure regimen, resistance to bacterial or parasite infection was decreased and tumor incidence in animals challenged with tumor cells was increased at ≥2 mg DES/kg/d (Dean et al., 1980). T-cell-mediated resistance to a nematode infection was suppressed by 5 d of exposure to 0.2 mg DES/kg/d if exposure began on the day of infection; if exposure commenced 5 d before or 3 or 8 d after infection, decreased resistance was only observed at the highest dose (8 mg/kg/d) (Luebke et al., 1984).

Mode(s) of Action

DES is a potent estrogen, and likely affects immune function via the estrogen receptor (ER). Evidence includes similar effects of known estrogens (17β-estradiol) on the immune system of adult and neonatal rodents, blockade of certain immunotoxic effects by pharmacologic antagonism of the ER (Luster et al., 1984), and antagonism of estrogen-mediated immune system effects in mice lacking ERα (Staples et al., 1999). DES appears to target precursor cells in the bone marrow (adults and neonates) and fetal liver (neonates), producing a long-lasting or perhaps permanent reduction in numbers of precursor cells. This defect explains a significant portion of long-lived immunosuppressive effects (e.g., Kalland’s 1984 paper on suppressed NK activity), although the effects of adult exposure also includes damage to the thymic epithelium (Luster et al., 1984). The underlying mechanism of long-term suppression following exposure of the developing immune system to DES is not known, but the default assumption is that a critical cell population is lost to developmental exposure; either this purported population is refractory to estrogen-mediated ablation in adults or repair and recovery mechanisms are present in adults that are lacking in the developing immune system.

Data Gaps

There has been no systematic evaluation of persistent DES-mediated immunosuppression in adult animals. Dose-response data are not available for many of the of the developmental exposure studies that revealed persistent effects.


In utero exposure to 0.1 mg DES/kg during the last trimester of pregnancy suppressed T-cell- and B-cell-mediated responses only in female offspring. The gender dependence of effects was remarkable in that T-independent responses in male offspring were enhanced, yet suppressed in females. Exposure during gestation produced effects that persisted into the equivalent of young adulthood. In neonates there appears to be a critical developmental window during PND 1–5, during which exposure to DES produces persistent immune system defects that last well into adulthood or persist for most of the normal life span of the mouse. These effects are among the most persistent reported for any chemical. In adults, immunosuppression occurs at doses similar to those that produce immunotoxicity in developing animals. However, the immune system-related endpoints that have been evaluated over time in exposed adult animals (bone marrow cellularity, thymus weights) recover relatively quickly (Forsberg, 1984). In adults, recovery may occur so quickly that suppression of cell function or resistance to infection may require ongoing exposure to maintain suppression.


Immunotoxicity has been reported at similar doses when exposure occurs during late gestation, early postpartum, or as adults. However, the distinguishing feature of developmental exposure to DES is the persistence of effects, some of which are still apparent in very old mice. In contrast, immune system-related endpoints that have been evaluated (bone marrow cellularity, thymus, weights) suggest that adults recover relatively quickly (Forsberg, 1984).


  • The comparative immunotoxicity of five selected compounds following developmental or adult exposure, Journal of toxicology and environmental health. Part B, Critical reviews, NCBI PubMed, PMID: 16393867, 2006 Jan-Feb.
  • Featured image radicalremission.

Prenatal DES exposure linked to Hashimotos thyroiditis

Drug exposure, pregnancy outcome and fetal and childhood development occurring in the offspring of mothers with systemic lupus erythematosus and other chronic autoimmune diseases

2006 Study Abstract

Most autoimmune diseases occur more commonly in females and many of these young women wish to become mothers. For pregnancy to proceed successfully immunomodulation and physiological changes preparing the reproductive system need to occur.

Pregnancy occurring in a chronically ill mother who requires medications in order to maintain her own health and who may have already incurred significant organ pathology gives rise to several problems and so four questions arise:

  1. What will be the effect of the pregnancy on the underlying disease?
  2. What will be the effect of the disease on the outcome of pregnancy?
  3. How to manage the disease, just prior to, throughout and immediately after the pregnancy?
  4. The long term fetal and childhood effects of maternal disease and its management.

This paper reviews the current literature pertaining to these questions in patients with systemic lupus erythematosus (SLE) and other chronic rheumatic and autoimmune diseases.


… “Other evidence suggests that the risk of autoimmune disease, particularly Hashimotos thyroiditis, is also increased in individuals exposed to DES in utero.” …


  • Drug exposure, pregnancy outcome and fetal and childhood development occurring in the offspring of mothers with systemic lupus erythematosus and other chronic autoimmune diseases, Lupus, NCBI PubMed, PMID: 17153855, 2006.
  • Featured image cleveland clinic.

Subchronic toxicology of diethystilbestrol in the mouse

image of female-mice

The liver, bone marrow, and thymus are major target organs for DES, 1983


This study evaluated the subchronic (14-day) toxicity of selected (0.2, 1.0, and 4.0 mg/kg) daily subcutaneous injections of diethylstilbestrol (DES) in female (C57B1/6 X C3H)F1 mice.

Parameters observed included body and organ weights, gross organ morphology, histopathology, clinical chemistry, and hepatic microsomal enzyme activities.

The liver, bone marrow, and thymus are major target organs for DES.

  • Liver enlargement, with associated histopathological changes consistent with mild hepatitis, centrolobular necrosis, and sinusoidal changes were observed. Supporting the histological changes were alterations in serum enzyme levels and microsomal enzyme activity.
  • Bone marrow changes included decreases in the number of cells as well as the number of colony forming units per gram stem cells.
  • Toxicity to the thymus was evidenced by decreased thymic weights and lymphocyte depletion. The hepatic and thymic effects were observed at the lowest (0.2 mg/kg) dose. Although all parameters were not assessed for recovery, those that were evaluated returned to control levels by thirty days after treatment.


  • Subchronic toxicology of diethystilbestrol in the mouse, Drug and chemical toxicology, NCBI PubMed, PMID: 6628266, 1983.

Increased DES in hepatitis E virus-infected pregnant women promotes viral replication

Pregnant women with high DES and/or immunosuppression will be vulnerable to HEV infection, study says, 2018


Hepatitis E virus (HEV) infection causes subclinical diseases, leading to high mortality (>25%) in pregnant women. HEV replication is aggressively escalated in pregnant women, especially in the third trimester of pregnancy. Oestrogen plays an important role in pregnancy. However, the pathogenesis of HEV in pregnant women or immunosuppressive pregnant women (such as HIV-infected or organ-transplanted pregnant women) remains unclear.

We investigated the role of oestradiol in HEV infection in a cell culture system. HEV-infected pregnant women had significantly higher oestradiol levels compared with uninfected individuals. HEV infection was significantly increased in cells treated with analogues of oestradiol, diethylstilbestrol (DES) or 17β-oestradiol in a dose-dependent way. However, tamoxifen, an antagonist oestrogen, inhibited HEV replication. HEV infection inhibits oestrogen receptor (ER-α) expression.

Immunofluorescence and co-immunoprecipitation assays indicated that ER-α interacted with the helicase of HEV ORF1 indirectly. More importantly, HEV infection was exacerbated in immunosuppressive cells treated with an inhibitor of PI3K-AKT-mTOR signal pathway (LY296004) and supplemented with pregnant women serum with high oestradiol simultaneously.

These results strongly suggest that pregnant women with high oestradiol and/or immunosuppression will be vulnerable to HEV infection.


  • Increased oestradiol in hepatitis E virus-infected pregnant women promotes viral replication, Journal of viral hepatitis, NCBI PubMed, PMID: 29345855, 2018 Jun.
  • Featured image Samuel Zeller.

Antenatal exposure to DES: lessons learned…future concerns

DES-exposed offspring : certain complications have no time limit and continued follow-up is necessary, 2007


The short- and long-term effects of the widespread use of diethylstilbestrol (DES) over 3 decades have become a distant memory for many clinicians. Others are too young to remember the flurry of activity in the early 1970s on the part of many medical centers to identify the offspring of women who were prescribed DES during their pregnancies.

This medication was given in an attempt to prevent multiple pregnancy-related problems such as miscarriage, premature birth, and abnormal bleeding.

The recognition of the association of DES with an increased incidence of cervical and vaginal cancers in very young women led the Food and Drug Administration to ban its use during pregnancy in 1971.

Other pregnancy-related problems for the daughters and genitourinary tract changes in the sons did not become apparent until years later.

Ongoing follow-up of these offspring has raised concerns for their future as well as their mothers’ future. Clinicians need to be up-to-date with current knowledge regarding risks for cancer and other health-related issues.

Abstract (Third-Generation Effects)

Animal studies have shown tumor growth in older third-generation mice (human equivalent to age 70).

Multigenerational studies in humans are currently underway.

Several small studies of teenage third-generation females have not shown the same type of changes as in their mothers. Sons of DES daughters are at increased risk for hypospadias.


  • Antenatal exposure to DES: lessons learned…future concerns, Obstetrical and gynecological survey, NCBI PubMed PMID: 17634156, 2007 Aug.
  • Image credit wise owl tea ‏.

DES effects on the mammary gland: rodent models and epidemiological studies

EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals, 2015


In addition to the better-known effects of early-life DES exposure on reproductive tract development and vaginocervical cancer in humans, animal studies have also shown that DES exposure affects mammary glands. In utero and lactational exposure to high doses of DES increased mammary gland growth and decreased the number of TEBs. Neonatal high-dose exposure to DES triggered extensive ductal dilation at P33 and promoted precocious lactogenesis in postpubertal, nulliparous 12-week-old female mice. In contrast, low-dose DES reduced ductal branching at P6 and P33. Low-dose exposure to DES during pregnancy caused impaired lactation in rats.

Gestational exposure of DES in rats resulted in an increase in spontaneous mammary gland tumors. Furthermore, multiple studies in mice showed that prenatal exposure to DES increased the risk of mammary tumorigenesis in females exposed to a known carcinogen, as well as the numbers of TEBs. In mice treated prenatally with DES there was a significant increase in enhancer of Zeste homolog 2 (EZH2) protein and EZH2 activity (measured by increased mammary histone H3 trimethylation)—a histone methyltransferase that may be linked to breast cancer risk and epigenetic regulation of tumorigenesis, as well as an increase in adult mammary gland EZH2. However, two studies found that relatively high-dose exposure during neonatal development reduced TEB numbers and prevented spontaneous mammary gland tumors. The mechanism for effects of DES on reproductive tissues likely varies by tissue. Taken together, this highlights the likelihood that DES daughters may have increased risk of adverse breast outcomes, cancer, and developmental abnormalities of the vagina.


  • Full study (free access) : EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals, Endocrine Reviews, Volume 36, Issue 6, Pages E1–E150,, 1 December 2015.
  • Image credit Esther Wechsler.

DES Daughters susceptibility of the mammary gland during the perinatal period

Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement, Endocrine Reviews, 2009


Direct evidence of prenatal estrogen exposure and breast cancer risk is being gathered from the cohort of women born to mothers treated with DES during pregnancy and is discussed above (see Sections II and III).

These women are now reaching the age at which breast cancer becomes more prevalent.

In the cohort of these women who are aged 40 yr and older, there is a 2.5-fold increase in the incidence of breast cancer compared with unexposed women of the same age, suggesting that indeed, prenatal exposure to synthetic estrogens may play an important role in the development of breast neoplasms.

Consistent with this, experiments in rats showed that prenatal exposure to DES resulted in increased mammary cancer incidence during adulthood. These experiments illustrated that rats exposed prenatally to DES and challenged with the chemical carcinogen dimethylbenzanthracene (DMBA) at puberty had a significantly greater incidence of palpable mammary tumors at 10 months of age than animals exposed prenatally to vehicle. In addition, the tumor latency period was shorter in the DES-exposed compared with the vehicle-exposed group.

Both the epidemiological and experimental data are consistent with the hypothesis that excessive estrogen exposure during development may increase the risk of developing breast cancer.

In summary, exposure to estrogens throughout a woman’s life, including the period of intrauterine development, is a risk factor for the development of breast cancer. The increased incidence of breast cancer noted during the last 50 yr may have been caused, in part, by exposure of women to estrogen-mimicking chemicals that have been released into the environment from industrial and commercial sources. Epidemiological studies suggest that exposure to xenoestrogens such as DES during fetal development, to DDT around puberty, and to a mixture of xenoestrogens around menopause increases this risk.


  • Full study (free access) : Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement, Endocrine Reviews, NCBI PubMed PMC2726844, 2009 Jun.
  • Image credit pino naigro.

Prenatal DES exposure and risk of multiple sclerosis

This is the first study to assess directly the relation between prenatal DES exposure and risk of multiple sclerosis (MS). Small preliminary studies have suggested an increased risk of any autoimmune disease or, more broadly, of diseases involving impaired immune function among individuals with prenatal DES exposure. Experimental studies in laboratory animals as well as human case series have also indicated altered immune cell function associated with DES exposure, such as abnormal natural killer cell activity, T cell-mediated immunity, and thymic development.

Prenatal and Perinatal Factors and Risk of Multiple Sclerosis, 2009


A potential role of prenatal and perinatal exposures in autoimmunity has been hypothesized, but few studies have examined the relation between various prenatal and perinatal factors and risk of multiple sclerosis (MS).

The study population included participants in the Nurses’ Health Studies, 2 prospective cohorts that together comprise 238,381 female nurses, who self-reported exposure to prenatal and perinatal factors. In addition, 35,815 nurses’ mothers participated by providing detailed information regarding experiences surrounding their daughter’s birth. The following prenatal and perinatal factors were studied in relation to MS: fetal growth, birth season, preterm birth, mode of delivery, maternal weight gain, medical conditions, medication use, diethylstilbestrol exposure, prenatal health care, maternal activity level, maternal obstetric history, parental age, and prenatal and childhood passive smoke exposure.

For in utero diethylstilbestrol (DES) exposure, assessed in the NHS-II in 1993, a confirmation questionnaire was sent to all nurses who self-reported DES exposure to classify the level of certainty (very certain, somewhat certain, not certain, or not exposed). The current analysis uses a conservative approach and compares those who were very certain of DES exposure with those who self-reported as nonexposed.

The sample included 723 confirmed MS cases, including 383 with diagnosis after reporting prenatal and perinatal factors. Few associations were observed. These included an increased risk among women whose mothers reported late initiation of prenatal care (after the first trimester) (27 cases, rate ratio = 1.6; 95% confidence interval = 1.0–2.4), diabetes during pregnancy (2 cases; 10;2.5–42), and maternal prepregnancy overweight/obesity (20 cases; 1.7; 1.0–2.7). Results also suggested a possible increase in incident MS risk among women with prenatal diethylstilbestrol exposure (9 cases; 1.8; 0.93–3.5).

The featured image shows the univariate age-adjusted and multivariate-adjusted RRs and 95% CIs for the association between self-reported prenatal DES exposure and risk of MS in the NHS-II. The univariate analysis restricted to all incident cases and that restricted to cases diagnosed after 1993 both showed an increased risk of MS associated with in utero exposure to DES, with effect estimates exceeding 2.

This study provides modest support for a role of prenatal factors in MS risk. The results should be interpreted cautiously due to the limited statistical power, potential for exposure misclassification, and possibility of chance findings.


  • Full study (free access) : Prenatal and Perinatal Factors and Risk of Multiple Sclerosis, Epidemiology, NCBI PubMed, PMC3132937, 2009 Jul.
  • Featured image table/T2.

Hysteroscopic Metroplasty for the DES Drug Related Uterus

Review and meta-analysis, Journal of minimally invasive gynecology, 2013

Study Abstract

The introduction of hysteroscopy to diagnose and treat intrauterine conditions, specifically to divide the uterine septum, or metroplasty, has replaced the traditional laparotomy approach, and objective results demonstrate its salutary effects in women treated.

Hysteroscopic metroplasty averts the implications of major invasive abdominal surgery, with good and satisfactory results in pregnancy and live-birth rates, despite the lack of prospective, randomized, controlled studies.

A careful review of the published results supports this type of treatment when the uterine septum adversely affects normal reproductive function.