Secular Trends of Reproductive Indices in Chuvashian Women

Body size at birth in babies born during World War II: The evidence from Poland

OBJECTIVES

The objective of the study was to determine whether exposure of pregnant women to stresses caused by World War II (WWII) negatively affected pregnancy and perinatal outcomes.

METHODS

Individual medical documents deposited in the Gynaecology and Obstetrics Clinic of Medical University, Poznań (1934-1943; N = 7058) were evaluated. These were divided into two birth cohorts: before WWII and during it. Frequency tables were constructed for the numbers of pregnancy outcomes: miscarriages, stillbirths, live births, and neonatal deaths, according to the period of birth and sex of a child. The numbers of recorded days were standardized and the numbers of cases per day were computed. Statistical differences in the averages (medians) between periods and years under study were tested. Birth weight, length, and body mass index (BMI) were compared according to the periods related to WWII.

RESULTS

Significant differences in proportions of males, females, and subjects with unknown sex were found between the periods: a higher proportion of males and different structure of/within negative outcomes were found during WWII. Children born during WWII were heavier and longer than those born before it.

CONCLUSIONS

As an explanation, adverse conditions of WWII, related to the psychological stress and food shortages, could have influenced greater elimination of fetuses and neonates of male sex during pregnancy and shortly after delivery. Higher average body size in newborns recorded during WWI could be explained by a hidden process of increased early prenatal mortality of weaker individuals, differences in average gestation length between the periods, differences in parity, or some undocumented differences in social/ethnic composition of the sample.

Leukocyte telomere length pattern in a Chuvash population that experienced mass famine in 1922-1923: a retrospective cohort study

BACKGROUND

To our knowledge, there are no experimental studies that have addressed the effects of starvation on the maintenance of telomere length. Two epidemiologic studies that have addressed this topic gave controversial results.

OBJECTIVE

We characterized leukocyte telomere length (LTL) in a Chuvash population that was comprised of survivors of the mass famine of 1922-1923 and in these survivors' descendants.

DESIGN

The tested cohort consisted of native Chuvash men (n = 687) and women (n = 647) who were born between 1909 and 1980 and who resided in small villages in the Chuvash Republic of the Russian Federation. Data were gathered during 3 expeditions undertaken in 1994, 1999, and 2002. With the use of this method of gathering the study cohort, we were able to treat age and birth year as independent variables (i.e., after adjustment for age, we were able to analyze how LTL correlates with a birth year in the interval between 1909 and 1980). The DNA of peripheral blood leukocytes was used to measure the telomere length with a quantitative polymerase chain reaction technique.

RESULTS

The main observations were as follows: 1) there were shorter leukocyte telomeres in men born after 1923 (i.e., after the mass famine) than in men born before 1922 (i.e., before the mass famine); 2) there was a stable inheritance of shorter telomeres by men of ensuing generations; and 3) there was an absence of a correlation between LTL and birth year in women.

CONCLUSIONS

Our study does not provide direct evidence for leukocyte telomere shortening in famine survivors. However, the comparative analysis of LTL in the survivors and their descendants suggests that such an effect did take place. The study also implies that mass famine may be associated with telomere shortening in male descendants of famine survivors. This observation is in agreement with the "thrifty telomere hypothesis" predicting that longer telomeres are disadvantageous in nutritionally marginal environments.