The rise of multiple births in Brazil

Aim: The aim of this study was to assess the rise in multiple births and its influence on trends of low birth weight (LBW) rates in Porto Alegre, Brazil. Methods: This is a registry-based study of live births from 1994 to 2005 obtained from the national live birth information system. Chi-square tests for trends were assessed for LBW and multiple birth rates. The impact of multiple births on LBW trends was assessed by sequential modelling, including year and further adjustment for multiple births. Risk factors for multiple births were assessed using the Poisson regression. Results: A total of 263 252 live births were studied. The LBW rate increased from 9.70% to 9.88% (p < 0.001) and the multiple birth rate rose from 1.95% to 2.53% (p < 0.001). LBW rate increased among twins, from 57.14% to 63.46% (p = 0.001). The twin birth rate rose by 24.7%, while the rate of triplets or higher-order increased by 150%. Multiple births may be responsible for 23.9% of the increase in the LBW rate over the period. Mothers with higher levels of schooling, older mothers and mothers delivering in private hospitals were more likely to deliver multiple births. Conclusions: It seems that both the increase in multiple births and in the LBW among multiple births contributed to this rise in overall LBW rate.

Economic Incentives to Conserve Wildlife on Private Lands: Analysis and Policy

Some believe that provision of private property rights in wildlife on private land can provide a powerful economic incentive for nature conservation because it enables property owners to market such wildlife or its attributes. If such marketing is profitable, private landholders will conserve the wildlife concerned and its required habitat. But land is not always most profitably used for exploitation of wildlife, and many economic values of wildlife (such as non-use economic values) cannot be marketed. The mobility of some wildlife (their fugitive nature) adds to the limitations of the private property approach. While some species may be conserved by this approach, it is suboptimal as a single policy approach to nature conservation. Nevertheless, it is being experimented with in the Northern Territory of Australia where landholders have the possibility of harvesting on their properties a quota of eggs and chicks of red-tailed black cockatoos for commercial sale. This scheme is expected to provide an incentive to private landholders to retain hollow trees essential for the nesting of these birds. Aspects of this approach are analysed using this case, and related ones, from Northern Australia. It is noted that the private property rights approach adopted in southern Africa is unlikely to be equally successful everywhere. The long-term survival of some species depends on their ability to use private lands without severe harassment, either for their migration or to supplement their available resources, for example, the Asian elephant in Sri Lanka. Nature conservation on private land is often a useful, if not essential, supplement to conservation on public lands. Community and public incentives for such conservation are outlined.