>>33030704The magic number is either 32 or 35 depending on which literature you believe. The pregnancy will be categorized as high risk but modern medicine has advanced enough that the chances of anything major happening to the mother is minimal.
At around 10 weeks your OB will request for a NIPS anyway so you can check if they baby has any genetic problems (if you wanna abort) and at 20 your doctor will request for a CAS to check again.
TLDR you can still impregnate your hags. Just make sure to plan your pregnancy and seek medical care at once when you suspect that your hag is pregnant. Even better if you seek consult prior to the baby making process so your doctor can prescribe vitamins to prevent other birth defects