Unintended pregnancies exist, and people have sex. But you're not going to get pulled over and cited for sexing without a license, because it tends to happen in private. So how should an insurance company verify that someone isn't having sex that could result in an immediate need for prenatal care? What happens when you're allowed to opt out, but your contraceptive fails and you have a kid anyway? The risk of ectopic pregnancies and/or miscarriages is high pretty early on, and many of those present in the ER where it's ludicrously expensive to even breathe the air.
How about diabetes or mental health care, should you be allowed to opt out of that coverage it you're sure™ it's not going to happen to you? Can women opt out of most everything to do with the prostate?
On top of all of this, as another commenter explained, the marginal cost of prenatal/pregnancy/postnatal coverage isn't even all that high. The cost of managing the opt-out would probably destroy any savings you were hoping to realize.
How about diabetes or mental health care, should you be allowed to opt out of that coverage it you're sure™ it's not going to happen to you? Can women opt out of most everything to do with the prostate?
On top of all of this, as another commenter explained, the marginal cost of prenatal/pregnancy/postnatal coverage isn't even all that high. The cost of managing the opt-out would probably destroy any savings you were hoping to realize.