Omega6 polyunsaturated fats are linked to some risks for the new mother and the unborn child.
As a rule, in the Western and also Italian diets, the consumption of omega6 polyunsaturated fatty acids is much higher than it should be . In particular, there are many studies that point the finger at linoleic acid, which causes inflammation and increases cardiovascular risks.

This fatty acid is found mainly in soybean oil, grape seed oil, sesame oil and wheat germ oil, but also in mayonnaise and sunflower oil is present for almost 40% every 100 grams. Finally, peanut oil, sunflower seeds, rice oil, pumpkin seeds and rice oil and rapeseed oil also have it in very high quantities, from a quarter to a fifth about 100 grams. Also considering that this fatty acid is found in many other foods, from the fatty parts of pork to olive oil to pistachios, walnuts and almonds, if you are not careful it is easy to overdo it.

A correct daily dose is not established: the current one, of 16 grams for men and 12 for women, is already considered excessive, and results from the analysis of diets from 1990 onwards. Before, much less was consumed. Although essential, this type of fatty acid should not exceed about 8 grams per day for men and 6 for women .

Fried foods, seed abuse, and many packaged foods or sauces have these oils among the ingredients (even in organic).
Now, a study in The Journal of Physiology reveals that a higher content of linoleic acid in the diet is also risky for the pregnant woman.

OMEGA 6 IN PREGNANCY: LINOLEIC ACID RISKY FOR THE GESTANT

According to the new study, exceeding the maximum dose by three times (so I assume a consumption of about 18 grams per day, equal for example to 2 and a half tablespoons of soybean oil or less than about 40 grams of mayonnaise) per day for women in pregnancy can lead to the formation of inflammatory proteins in the liver. These proteins would cause more uterine contractions, but at the same time block the development of the fetus.

So on the one hand there could be a risk of miscarriage or gestational complications with too many omega 6s in pregnancy. On the other hand, the risk of problems in the development of the child. The concentrations of cholesterol and leptin would also increase: the latter could lead to overweight in the pregnant woman.
It also appears that women who consume too many fatty acids give birth to more girls than boys.