The U.N. Children's Fund says in its latest annual report that half a million women die in childbirth and more than four million newborns are also lost each year, and that most of those deaths are preventable. But UNICEF also used the occasion to report that about one third of the people killed in Gaza since late December, are children.

UNICEF Executive Director Ann Veneman says that more than 320 children have been killed, and more than 1,500 wounded, since the onset of the latest violence in Gaza. Veneman says the impact on children goes even further.

"The situation in Gaza is a very dire one for children; more than half the population of Gaza is children. Just the psychological impact of this kind of conflict on children is something of great concern as well. It is a very difficult situation; it is difficult to get humanitarian access," she said.

Veneman adds the conflict has already caused serious health risks for women giving birth in Gaza and for their newborn babies.

"The health systems are having difficulty functioning, getting access to them," she said. "The lack of power and electricity and water, is making delivery of the health care very difficult. The hospitals are full of injured, and if a mother comes ready to deliver, the likelihood is she may not get the care she needs, or could be turned away."

At the same event, South African Health Minister Barbara Hogan told reporters that the crisis in Zimbabwe has also added enormously to the burden of caring for mothers and babies throughout southern Africa.

"The whole state health system has collapsed, if we are looking at the health of our children, and our women, the whole of southern Africa is affected by the breakdown of health systems in Zimbabwe," she said.

The comments were made at the launch of UNICEF's annual State of the World's Children report, which this year focuses on the link between maternal and newborn health.

The study shows that a woman in a least developed country is 300 times more likely to die from complications related to pregnancy or childbirth than a woman in the developed world. And a child born in a least developed country is nearly 14 times more likely to die within 28 days, than a child born in an industrialized country.

Veneman says the impact is greatest in Africa and Asia.

"The burden is disproportionately heavy in Africa and Asia," she said. "Ninety-five percent of maternal deaths occur in Africa and Asia combined and 90 percent of newborn deaths occur in Africa and Asia. In southern Africa a high number of maternal and newborn deaths are related to HIV/AIDS. The health of the child is inextricably linked to the health of the mother."

Veneman notes that many women and newborns die needlessly and says this can be prevented by ensuring mothers and babies have adequate nutrition, that hygiene practices are improved and through better access to skilled health care and emergency services at birth. She said research indicates that around 80 percent of maternal deaths could be prevented if women had access to essential maternity and basic health care services.