Somewhere in Nigeria, a woman is pregnant and alone. She cannot afford antenatal care. She does not know where to go, or who to call. And without intervention, she may not survive her delivery. This is not a rare story. Nigeria accounts for more than a quarter of all maternal deaths worldwide. A woman giving birth there faces a 1 in 19 lifetime risk of dying during pregnancy or childbirth. In the United States, that risk is 1 in 4,900. The gap between those two numbers is not fate. It is a fail…