Almost 10 per cent of pregnant woman are victims of violence during pregnancy, putting their unborn children at risk, new research suggests.
Two studies from of Auckland University, published in the Australian and New Zealand Journal of Obstetrics and Gynaecology, have provided previously unavailable information on women's reproductive health in New Zealand.
One of the studies found almost 10 per cent of pregnant women had experienced violence.
Three-quarters of those women had been beaten by the same person, which was usually the father of the child, before they were pregnant.
For most of these women, the violence stayed the same or got worse after they became pregnant, the study said.
Violence during pregnancy was associated with both women and their partners being less likely to want the pregnancy.
The study said women's experience of partner violence was associated with both increased risk of miscarriage (1.4 times more likely), and increased likelihood of abortion (2.5 times more likely).
Also, women who experienced violence during pregnancy were much more likely to smoke tobacco while pregnant - 67 per cent - than those who had not experienced violence - 22 per cent.
Positive findings from the study included the nearly universal level of antenatal care and post-natal care that women received.
The second study reported almost a third of women have had at least one miscarriage and at least one in 10 women had terminated a pregnancy.
Asian women were 3.5 times more likely to have an abortion compared with Caucasian women, the study found.
Dr Janet Fanslow, senior lecturer at the university's school of population health and principal investigator of the studies, said the findings reinforced the need for the current Ministry of Health programme of action on responding to family violence.
"Settings that provide reproductive health services for women need to continue to train their staff, and ensure that they have adequate community links, to assist women to respond to current and past experiences of partner violence," she said.
The study interviewed nearly 3000 women aged 18 to 64 from the Auckland and Waikato regions about their experiences of violence.