Women in combat?

Maybe not so much.  Data from 2016 indicate that 16% of deployed women became pregnant on deployment.  If we assume that only 10% of combat troops are women, we would infer that in a given year, about 1% of troops on a given ship would need to be de-deployed in a year.  20 years back, about 10% of the women on the "Love Boat" became pregnant, so it's a consistent problem.

This is  close to the proportion of soldiers in a unit that General Patton said would die in a really terrible battle when he was preparing his men for Operation Overlord.  Now we can argue all day (in a silly way, but we can) about how well qualified women are for combat positions in terms of physical and mental aptitudes, but the simple fact of the matter is that attrition of female soldiers and sailors due to pregnancy is similar to the effects of a major battle on units. 

And really, it's no surprise.  What's going on is simple; when you take young, healthy people ten thousand miles from home and put them in a situation where they are lonely and more than a little bit scared, they tend to fornicate.  All the regs in the world can't stop that, but our regs ought to acknowledge it.

One final note; a West Point graduate of my acquaintance told me a few weeks back that when the Army tried to correlate success as an officer to the experience at USMA, the only thing that correlated well was how well the candidates did in their physical education classes.  This stuff matters.