It is possible for alkaline phosphatase
to rise in pregnancy but not AST and ALT.
AST and ALT doesn't rise in pregnancy and if they are high,it could mean a dangerous thing.
There are several causes for it,like..
Per eclampsia,onset of high blood pressure
,proteins in urine,HELLP syndrome
A,B and C etc.
You must consult your doctor and try to find the cause and it's treatment as early as possible.