This 2014 rodent study showed how to make a less-capable pup by stressing the mother early in gestation. The study centered on a placental enzyme (OGT) that translates a mother’s stress into neuroprogramming of her developing fetus.
One finding was that this enzyme was less plentiful when the fetus was male compared with female.
Another finding was that the enzyme was less plentiful when the mother was stressed early in gestation, compared with unstressed mothers.
Informed by the first two findings, the researchers studied the placentae of male pups where the mother was stressed early in gestation. They found that these placentae had lower levels of an enzyme (Hsd17b3) that converts the precursor androstenedione into testosterone.
The resultant finding was that the male pups of stressed mothers had lower levels of testosterone than the control group of male pups.
A fourth finding was that offspring of both sexes born with a placenta where the OGT enzyme was less plentiful had 10-20% less body weight, a condition that developed after weaning. The researchers attributed this finding to reduced mitochondrial function in the hypothalamus compared with normal mice.