As I recall from my reading of Sarek, getting close to two decades ago, Sarek and Amanda had medical help to conceive. So yes, it is possible, but not without outside assistance. Genetic engineers and fertility doctors and high-risk specialists and the like.
Interesting note on blood color: I was told many, many moon ago, that human blood is actually blue (thus the color of the veins visible in wrists and elbows and the like), but turns red when it's exposed to oxygen. I don't know how accurate this is, but that's what I was told by, I believe, a medical professional.
ETA: Those are all different dresses, in similar styles.