Aims: Though periconceptional intakes of folic acid could prevent the occurrence of spina bifida by 50 to 70%, the prevalence has not shown any decreasing tendency during the past 30 years in Japan. We aim to analyze various parameters through life style questionnaires and 3-day food records obtained from pregnant women the last 10 years, and to examine whether their life styles have been shifting to the direction of lowering the incidence of spina bifida.
Materials and methods: Life style questionnaires inquired of knowledge of folic acid in relation to preventing spina bifida during a pregnancy and other relevant parameters, which were collected from 11,861 participants during a period of from 2002 to 2011. Food records asked participants to semi-quantitatively describe diets and beverages they consumed for a 3-day period, which were collected from 1,081 pregnant women from 2003 to 2011.
Results: Life style questionnaires demonstrated that knowledge of folic acid and the proportion of those who took folic acid supplements elevated from 15.3 and 9.1% in 2002 to 43.7 and 61.5% in 2011, respectively, that comparison of those who took folic acid supplements from 2008 to 2011 residing in one of 8 districts of Japan showed a significant difference, i.e., the proportion of those in the Chugoku or Kyushu district being significantly lower compared to that in the Hokkaido district, and that other life style parameters have not much altered the past 9 years, e.g., those who conceived as planed being 67%, those who confirmed own pregnancy within 6 weeks of pregnancy being 70%, those who took balanced diets being 65%, and those who did not smoke or drink being 95% and 96%, respectively. Three-day food records revealed that the mean dietary folate intakes ranged from 260 to 360 microg/day in each year which were less than the recommended dietary allowance (RDA) publicized by the government, but that the proportion of pregnant women in the first trimester who consumed folic acid supplements from 4 weeks prior to to 12 weeks after conception increased from 7.4% in 2003 to 69.6% in 2011.
Conclusions: As a whole it could be stated that life styles of pregnant women have been shifting toward the direction the past 10 years where the risk for having a pregnancy afflicted with spina bifida is to be decreased. Medical doctors, nurses, midwives, dietitians and pharmacists are asked to repeatedly supply important information on folic acid and to advise taking folic acid supplements 400 microg a day to women planning to conceive or women in the reproductive age.