In 2015, almost two-thirds of women had a spontaneous vaginal birth, one-quarter had a caesarean section, and the remaining had an assisted vaginal birth. The average birthweight was 3.41kg and 3.7 per cent of women gave birth at home.
More than half of women who gave birth in 2015 were identified as overweight (28 per cent) or obese (25.6 per cent) - an increase over recent years.
The rate of caesarean births has increased, and are more common among women aged 35 and over, women in wealthier areas, and Indian and "other Asian" women.
Most babies were born at term, and only 7 per cent were pre-term.
Smoking while pregnant
Just over 14 per cent of pregnant New Zealanders smoked early in their pregnancy.
The report shows 14.2 per cent of pregnant women smoked, down 2 per cent compared to 2008 - about 1170 fewer smokers.
Health Minister Dr Jonathan Coleman said evidence was clear that the earlier pregnant women quit smoking, the better it is for their baby's health.
"Smoking is the primary preventable cause of stillbirth, premature delivery and low birth-weight for babies. It also increases babies' risk of sudden unexplained death in infancy (Sudi)."
The Government has a goal of cutting the overall rate of Sudi by 86 per cent, and 94 per cent for Maori, by 2025. Reducing the rate of smoking in pregnancy is a key focus as part of this work.
Women giving birth, by age group, 2015
• Younger than 20: 2799
• 20-24: 10,026
• 25-29: 15,831
• 30-34: 18,024
• 35-39: 9811
• 40 and older: 2466
Source: National Maternity Collection