Assisted reproduction technology in Australia and New Zealand 2005

This report presents data on success rates based on live delivery and how they vary by treatment type, women\u27s age and number of embryos transferred. Also included is information on birth outcomes such as multiple birth, gestational age, birthweight, and perinatal mortality

Sex ratio at birth of Australian babies and ART babies its determinants and their influences

The human sex ratio at birth (SRB) is an important demographic parameter in a population that has been a subject of studies in many scientific disciplines. Its increase or decrease can be used as a sentinel indicator for changes in a society and the environment. This doctoral study investigates four aspects of the SRB in Australian babies born between 1991 and 2007 and in babies born following assisted reproductive technology (ART) treatment between 2002 and 2007. First, a trend analysis for Australian babies reveals that the SRB in Australia is stable, at 51.4% males or 105.8 males per 100 females during the study period, compared to the significant increase or decrease in the SRB in the late 20th century in most developed countries in Europe and North America. Second, an analysis on the effect of maternal age, parity and plurality on the SRB indicates that slightly more males than females are potentially born to younger and/or first-time mothers, although this effect is not statistically significant. Babies born in multiple gestations are more likely to be female. Third, ambient temperature has a significant impact on the SRB. In Australia, the SRB is inversely related to the mean daily temperature, with a higher SRB in cool temperate regions and a lower SRB in hot tropical regions. Fourth, two ART procedures have a significant impact on the SRB. Intracytoplasmic sperm injection procedure results in a lower SRB, whereas blastocyst embryo transfer results in a higher SRB. This doctoral study provides the first detailed and comprehensive analyses of the relationship between SRB and environmental factors, and SRB and ART procedures. The results of this doctoral study indicate that exogenous factors can have greater influence on the gender survival of embryos and fetuses