Nothing is more important for a fetus than the adequate control of blood pressure in the mom.  We are seeing hypertension more and more often today in pregnant women as the rate of obesity has risen.  This study reviews treatment of hypertension in pregnant women.  TWH  

B12 is a really critical vitamin,  particularly in pregnant and breastfeeding women.  We've known for a long time that women who are vegetarians have a higher risk of B12 deficiency,  which may impact their fetus, and breastfed infants.