Changes in social and biological factors in New Zealand perinatal mortality

Perinatal mortality in New Zealand decreased substantially during the 1970s. In 1979 it had fallen by five per 1000 to 12. The decrease applied to both high risk and low risk infants. The greater reductions occurred in infants born to mothers younger than 20 or older than 35, in infants with birthweights under 2500 g and in infants of fathers with semiskilled or unskilled occupations. The differential between the rates for nuptial and ex-nuptial infants narrowed.

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