Trends in maternal mortality.
D000022:Abortion, Spontaneous; D000293:Adolescent; D000328:Adult; D005260:Female; D006331:Heart Diseases; D006801:Humans; D007239:Infections; D008428:Maternal Mortality; D009520:New Zealand; D006473:Postpartum Hemorrhage; D011225:Pre-Eclampsia; D011247:Pregnancy