Senior academics at the University of Otago have called for a free contraceptive programme to be made available to teens before they become sexually active.
In an article in the British Journal of Obstetrics and Gynaecology Dr Neil Pickering and Dr Lynley Anderson from the university's Bioethics Centre and Dr Helen Paterson from its Department of Women's and Children's Health say teen pregnancy places significant costs on the individual and society, and is associated with higher perinatal mortality.
"We also know the children of teen pregnancies do poorly in statistics related to poverty, imprisonment and teen pregnancy.
"In a worryingly large number of cases, pregnancy in the teenage years is bad for the teenager, is bad for the child of the teenager and it is bad for both of them during the whole pregnancy. Obviously that also impacts on society."
Dr Paterson says teenage pregnancy and abortion rates in New Zealand have improved recently, possibly since the LARC (long-acting reversible contraceptive) Jadelle became funded by Pharmac five years ago.
"If you use withdrawal as a method, pregnancy rates are 22 per cent per annum. If you use condoms it is 18 per cent, if you use the pill it is 9 per cent, and if you use a LARC it is 0.5 per cent."
Dr Pickering says there is a good case for making it an opt-out programme which provides adolescents with the opportunity to have a LARC, rather than having to go and seek care.
"For a programme to be effective you need to get as many people involved as possible and an opt-out programme seems to be more effective. You still get the right to say no and in terms of justice it treats everybody the same."
He says decisions around starting such a programme should be made on pragmatic grounds and transparent moral grounds, rather than on fears such as adolescents becoming more sexually active - something the evidence doesn't support.
"If you look at it rationally and with a sense of what's doing best for people, even with your economic hat on, it makes sense."