The following graphs make plane the 12-fold variation in the published rate of gastroschisis across Canada, taken directly from the attached major review by the Canadian Government (see Table B7.2A/B on page 115)!!!!
Naturally these crude rates do not adjust for maternal age which is also known to be important.
However it is noteworthy that all 9 provinces for which data exists do not intersect the confidence intervals for Nunavut!!!!
I think these trends are very striking and very noteworthy, and also very consistent with what is seen in other places internationally.