How can the father and/or the grandmother get the medical records of the mother while she was pregnant?

My son was told in June that his girlfriends was pregnant. Therefore in August he married her. During this time her due date changed from march 30 to march 7 to April 19. My son never got to go to any doctor appts. On the morning of April 20 (full term supposedly) she called me to say that she had a blight ovum and that the baby had been dead for 6 to 8 weeks. Now we want to know that true about what is and or has been going on. My son had never felt the baby move either and thought it was a lie all along.

As far as I know, you can't. Those medical records are hers, and won't be given to you or anyone else without her express permission. You'd be pretty horrified if she asked for and got your records to check if you had a genetic disease you might pass to her baby. Even though she was pregnant with your son's baby, the records still relate to her, not the baby.

No one is entitled to look at anyone's medical records.
There are strict confidentiality laws that are put in place to protect everyone.

Unless the girl signs a release letting you have a copy of the medical records, you can't see them. They are protected information... doctor/patient privilege.

According to the information you gave, this girl was 11 months pregnant yet your son thinks the pregnancy was a lie? What does he think her condition was, bloating? Even though the baby had died, in order to get it out, she would still have to give birth to it, was there no funeral? I'm sure she didn't drive herself to the hospital for this procedure! I'm sorry, this story doesn't add up.

Not to mention that a blighted ovum is found early in pregnancy. A blighted ovum does not produce a baby, so there is no giving birth and there is no funeral, usually a D&C is performed.