For example, those who have studied insulin dependent diabetes in relation to infant feeding have unanimously confirmed the protective effect of breast feeding. The season of birth seems to be related to the risks of diseases as diverse as insulin dependent diabetes, schizophrenia or cataract. The season of birth also significantly influences height in adulthood, according to a convincing study of more than 500,000 Austrian men aged 18. This leads one to examine infectious diseases, and in particular viral diseases which are more common during certain seasons. This also leads us to look at nutritional factors, which may be highly influenced by the seasons, especially in the rural areas of certain countries.
Several rules are apparent from an overview of our data bank.
It is significant that in the study of health in rural Gambia the differences in mortality rate in relation to the season of birth are undetectable before age 15. It is worth noticing that one of the oldest studies in our data bank is about the case of women aged 15-22 who had an adenocarcinoma of the vagina in relation to the diethylstilbestrol used by the mother when she was pregnant. This is the case of a whole subgroup of research exploring the possible long term consequences of different sorts of medicalised conceptions. For obvious reasons significant results with long enough follow-up cannot yet be obtained. The high proportion of studies detecting correlations between fetal life and health later in life need to be interpreted.