Worldwide, the average number of births per woman has dropped from 5.0 in the 1950s to 2.5 in the 21st century. In most industrialized countries, the fertility rate is well below the replacement rate and an increasing number of couples seek fertility treatment. The decline in the fertility rate may be explained by the availability of effective contraceptive methods, a desire to have few children, high age at first pregnancy, altered lifestyle, as well as an increase in the prevalence of chronic diseases.
Very few large prospective studies on fertility exist as pregnancy planners constitute a hard-to-reach population, because they do not congregate in specific places or announce their pregnancy intentions in public. Thus, we initiated this Internet-based study of pregnancy planners to evaluate the relation between several lifestyle and behavioral factors and delayed conception. The study was established in Denmark as the country has a long tradition for collecting and storing data on various aspects of health. Hence, we have the possibility of combining self-reported data with data from a wide range of registries including the Danish Medical Birth Registry, The In Vitro Fertilization Registry, and The Danish National Registry of Patients. The registries cover the entire population and are linkable at the individual level using the unique ten-digit personal assigned to every Danish resident.
“SnartForaeldre” means SoonParents. The study, which is entirely Internet-based, is conducted in Denmark and was launched in 2011 as a successor to SnartGravid (SoonPregnant). The overall aim of the study is to examine whether lifestyle factors – such as diet, exercise and medication use – influence female and male fertility.
SnartForaeldre.dk has a sister study, PRESTO, which is conducted in North America. The two studies are based on the same questionnaires – with minor culture-specific adaptions.