My advice to the couple? Get a good obstetrician well before conception; get the mother immunized against infections; eat a lot of fish (omega-3 fatty acids); take adequate doses of folate and vitamin D, perhaps even choline9; avoid smoking before and during pregnancy; adopt a healthy, balanced diet; avoid excessive weight gain and/or gestational diabetes; avoid contact with people with infections; avoid exposure to cat feces (toxoplasmosis); schedule frequent prenatal visits; and hope for a smooth and uneventful delivery and a newborn with an Apgar score of 9 or 10. All this will greatly reduce the non-genetic risks of schizophrenia, but is unlikely to modify the genetic risks. However, it has been shown that a combination of both genetic and non-genetic risk factors is associated with a more severe form of schizophrenia.10
Optimal prenatal and postnatal care can be helpful for couples with a family history of schizophrenia (without moving to deliver their baby in a rural village near the equator). However, if their child starts using marijuana during adolescence, all bets are off. The risk of schizophrenia and serious cortical tissue loss increases dramatically when a carrier of risk genes use Cannabis. But that’s another editorial, to be read by clinicians in states where marijuana has been (foolishly, I believe) legalized.