While I tend to believe that there is no wife or baby & so no miscarriage, having suffered 3 miscarriages & my mother suffered 8, I can not just ignore the slight possibility that there is a wife & there was a baby.
Gordon, babies self-abort for so many reasons (many unknown, some even before anyone is aware of the pregnancy), but also due to the woman being unloved/uncared for, overworked (including having to be on her feet too often &/or cooking over hot stoves) especially in the first trimester.
Babies can also self-abort due to shromosonal abnormalities that make it unviable for the baby to continue to grow. Then there can be problems with the shape/position/etc of the uterus & or cervix, not to mention issues re sperm & egg viability. Also the general health of the woman can impact on her ability to carry a child to term sa can both physical & emotional abuse. So if you really do call your wife "it" that is emotional abuse & may well be a cause of her miscarrying.
Perhaps you have already made her life hell - hence the miscarriage, if you want a baby you need to be considerate of your wife, the babies mother & of her health & needs.