The fact that the high mortality rate is occurring postpartum says to me that women are picking up infections and going septic or throwing clots, probably after C sections. The US has a high C section rate.
Since Asians have the highest rates of marriage and the least loss of death after childbirth and blacks have the lowest rates of marriage and the greatest deathrate after childbirth it would seem to imply that those who have the support of a man have the highest rate of surviving.