A Decrease in Sex Ratio at Birth Nine Months after the Earthquake in L'Aquila

Abstract

Introduction. Multiple factors influence the secondary sex ratio (SSR) including stress, which appears to affect mainly the males born. Objective. We evaluate the effects of the earthquake in L'Aquila on the SSR. Materials and Methods. The SSR for the first six months of 2010 was compared to that of the same period of 2008. The chi-square test and Fisher's test were used for the statistical analysis. Results. Nine months after the earthquake, an important reduction in the SSR was recorded: January 2010 versus January 2008 =0.62 versus 0.96. An overall fall in the SSR was also recorded when the first 3 months of 2010 were compared to the first three months of 2008: 0,82 versus 1,11. When the first three months of 2010 were compared with the second three months of 2010, a statistically significant increase of the sex ratio at birth was noted (0,82 versus 1,27).

Natural selection In Utero: Evidence from the great East Japan earthquake

“…Among these five studies, however, only that supporting selection in utero (i.e., Torche and Kleinhaus, ) used data of sufficiently understood provenance for inclusion in the Human Mortality Database (University of California Berkeley, 2012) and controlled for autocorrelation as well as secondary sex ratio changes in comparison populations. The study reporting no association (i.e., Tan et al, ) and two of those supporting reduced conception of males (i.e., Saadat, ; D'Alfonso et al, ) compare pre‐earthquake and postearthquake births estimated from hospital records or from sources with unknown accuracy and coverage. The third study (i.e., Fukuda et al, ) supporting reduced conception of males used validated vital statistics, but does not control for autocorrelation in the data or for changes in male births that occur in similar but unexposed populations.…”

The impact of catastrophic events on the sex ratio at birth: A systematic review

“…Summary of the main results. (A) Catalano et al, 2013; D'Alfonso et al, 2012; Doğer et al, 2013; Fukuda et al, 1998; Fukuda et al, 2018; Hamamatsu et al, 2014; Nandi et al, 2018; Saadat, 2008; Suzuki et al, 2016; Torche & Kleinhaus, 2012; Tourikis & Beratis, 2013. (B) Catalano et al, 2020; Grech & Borg, 2016.…”

“…The World Health Organization refers to a natural disaster as “an act of nature of such magnitude as to create a catastrophic situation in which the day‐to‐day patterns of life are suddenly disrupted and people are plunged into helplessness and suffering and, as a result, need food, clothing, shelter, medical and nursing care and other necessities of life, and protection against unfavorable environmental factors and conditions” (Assar, 1971, p. 24). For example, after an earthquake, an entire population can be evacuated and the government can declare a state of emergency, leading to a considerable number of people requiring assistance in the following months (D'Alfonso et al, 2012). Therefore, natural catastrophes typically represent a source of intense psychological stress (Han et al, 2021; Itoh et al, 2022; Kotozaki & Kawashima, 2012; Lugović‐Mihić et al, 2021; Mondal et al, 2013; North & Pfefferbaum, 2013; Wakashima et al, 2019).…”

Longitudinal changes in maternal and neonatal anthropometrics: a case study of the Helsinki Birth Cohort, 1934–1944

“…No statistically significant change was detected in the sex ratio either. Although there is some evidence to support the hypothesis that the sex ratio tends to increase shortly after a war or some other abrupt stress factors, such as an earthquake, 20 , 21 there are also contrary findings 22 …”