The poor substitutes for evidence in this 2018 US study guaranteed that human transgenerational epigenetically inherited effects wouldn’t be found in the generations that followed after prenatal diethylstilbestrol (DES) exposure:
“A synthetic, nonsteroidal estrogen, DES was administered to pregnant women under the mistaken belief it would reduce pregnancy complications and losses. From the late 1930s through the early 1970s, DES was given to nearly two million pregnant women in the US alone.
Use of DES in pregnancy was discontinued after a seminal report showed a strong association with vaginal clear cell adenocarcinoma in prenatally exposed women. A recent analysis of the US National Cancer Institute (NCI) DES Combined Cohort Follow-up Study showed elevated relative risks of twelve adverse health outcomes.
We do not have sufficient data concerning the indication for DES in the grandmother to determine whether adverse pregnancy outcomes in the third generation might resemble those of their grandmothers. Fourth generation effects of prenatal exposures in humans have not been reported.”
This study had many elements in common with its wretched cited reference  “Transgenerational effects of prenatal exposure to the 1944–45 Dutch famine” which is freely available at https://obgyn.onlinelibrary.wiley.com/doi/full/10.1111/1471-0528.12136.
That study’s Methods section showed:
- Its non-statistical data was almost all unverified self-reports by a self-selected sample of the F2 grandchildren, average age 37.
- No detailed physical measurements or samples were taken of the F2 grandchildren, or of their F1 parents, or of their F0 grandparents, all of which are required as baselines for any transgenerational epigenetic inheritance findings.
- No detailed physical measurements or samples were taken of their F3 children, which is the generation that may provide transgenerational evidence if the previous generations also have detailed physical baselines.
That study’s researchers drew enough participants (360) such that their statistics package allowed them to impute and assume into existence a LOT of data. But the scientific method constrained them to make factual statements of what the evidence actually showed. They admitted:
“In conclusion, we did not find a transgenerational effect of prenatal famine exposure on the health of grandchildren in this study.”
The current study similarly used the faulty methods 1-3 above to produce results such as:
“We do not have sufficient data concerning the indication for DES in the [F0] grandmother to determine whether adverse pregnancy outcomes in the [F2] third generation might resemble those of their grandmothers. [F3] Fourth generation effects of prenatal exposures in humans have not been reported.”
What did these researchers expect from a study design that didn’t include F3 subjects, which is the only generation that didn’t have direct DES exposure? And permitted non-evidence like educational level?
Human studies of possible intergenerational and transgenerational epigenetic inheritance are urgently needed. There will be abundant evidence to discover if researchers will take their fields seriously.
https://www.sciencedirect.com/science/article/pii/S0890623818304684 “Reproductive and Hormone-Related Outcomes in Women whose Mothers were Exposed in utero to Diethylstilbestrol (DES): A Report from the US National Cancer Institute DES Third Generation Study” (not freely available)