First report from the Plunket National Child Health Study: smoking during pregnancy in New Zealand.

The Plunket National Child Health Study is a 5-year longitudinal study of a birth cohort of 4285 children born in New Zealand during 1990-1991. This paper describes the major lines of epidemiological research, the methods and study design, and reports on the demographic data of New Zealand children. During this first report from the Plunket Child Health Study, we examine on the smoking rates of New Zealand mothers during pregnancy. Overall 33% of mothers smoked during pregnancy. Particularly high rates were found amongst teenage mothers,. Maori women, single women and women with lower educational levels. Over 60% of women in these categories smoked during pregnancy.