The most important consideration is the D antigen aka Rh antigen which doesn't affect the first pregnancy, as others have said. If mom is Rh- and dad is Rh+, there is a chance that the fetus is Rh+. During pregnancy and especially during childbirth or miscarriage, the mother and fetus exchange blood. Mom's body recognizes the fetus' Rh+ blood as foreign and generates antibodies against this factor. This won't affect the initial pregnancy. However, if mom gets pregnant again with an Rh+ baby, then the antibodies will cross the placenta and attack the baby's red blood cells, causing a disease called hemolytic disease of the newborn. Its a serious form of anemia that can kill the baby.

This is why Rh- moms are given Rhogam, an antibody against this antigen. The idea is that during that first pregnancy, the Rhogam will "hide" the Rh antigen from the mother's immune system, preventing the formation of those antibodies and protecting future pregnancies.

You can have HIV without having AIDS, and you can have fever and night sweats without having AIDS. One of the initial presentations of HIV infection is flu like symptoms. Those people don't have AIDS, they have very early stage HIV infection.

This is true, just a small correction for clarity. AIDS isn't really a set of symptoms. Its defined as an HIV infection that has progressed to a point where the person has a CD4 count under 200 or has an "AIDS-defining condition". The 2 often go hand in hand because these AIDS defining conditions usually happen at very low CD4 counts. So you can have AIDS and then actually regress back to just an HIV infection with HAART when the CD4 count recovers.

No, pain is an entirely subjective experience that you can't really objectively measure considering every single person exoeriences it differently. What may be a minor annoyance to one person is excruciating in another.

In medicine, we often will ask how bad something is on a scale of 1 to 10, but thats a ballpark measurement. Most of the time we visually assess for signs of extreme pain. If you walk into someone's room and they're writhing around, or they're sitting completely dead still those are both alarming. If someone with sickle cell disease says something hurts I usually assume they're experiencing a super high level of pain because they hurt every day. So if they tell us they're in pain they're in A LOT of pain. I won't have that mindset in someone who has no morbid health conditions.

Overall just very situational.