Yes, our instructions mention that Tretinoin cream should not be used ifpregnant, breastfeeding or planning a pregnancy.
Vit. A healthy and very important, even in pregnancy (vitamin supplements intended for pregnant women do contain vit. A because it is so important) but the problem starts when you reach excessive levels of vit. A. Excessive levels can theoretically be dangerous for the fetus (at least they were for rats), especially in the first stages of pregnancy. You have to be careful, particularly with your oral intake.
The companies producing vit. A creams advise not to use it in pregnancy, just to stay totally on the safe side. If you have just a couple of scars, it is OK but it should not be used on large areas. In your case, the areas are large.
In general, in pregnancy and breastfeeding, you must be careful with everything, not just vit. A. (BTW, dermarolling highly enhances the absorption of all substances applied on the skin right after rolling).