Paternal occupation and offspring sex ratio

Abstract

Between 1961 and 1997, there were 15 reports of unusual secondary sex ratios related to paternal occupation. Thirteen of these documented a statistically significant predominance of female births (low secondary sex ratios) to fathers working in specific occupations. Findings are summarized, as are authors' suggestions about possible causes for the observed phenomenon. In addition, a new study is reported, replicating the findings of low offspring sex ratios in the children of male anaesthetists. Discussion focuses on four possible explanations of the findings -sampling error, differential damage to sperm, the Trivers and Willard hypothesis (Trivers and Willard 1973), and the maternal dominance hypothesis (Grant

Firstborn offspring sex ratio is skewed towards female offspring in anesthesia care providers: A questionnaire-based nationwide study from United States

“…The viability of male-sex determining Y-bearing sperms[19] may be affected by occupational exposure to waste anesthetic gases that may affect OSR in anesthesia care providers[1] (both male providers as well as female providers). Such effects could occur from anesthetic exposure affecting Y-bearing spermatozoa in paternal genital tract (pre-coital life cycle of sperm) as well as in maternal genital tract (post-coital life cycle of sperm).…”

“…However, spermatozoa functionality tests following occupational exposure to anesthetics have been sparsely investigated. [1] Other peri-conceptional factors that may alter OSR include parental exposure to smoking,[20–22] alcohol abuse,[23–26] stress,[27] obesity,[28] or the use of hormones (exogeneous or endogeneous). [29]…”

“…A parental occupation such as anesthesia care provider can involve exposure of the parent to various chemicals in the work environment and has been correlated to skewed offspring sex ratios (OSR) favoring higher proportions of female offspring. [1] However, reported studies in anesthesiologists related to anesthesia practice and its effects on pregnancy including OSR were performed in the early 1970s and were based on small sample populations. [1–6] In addition to the documentation of higher risks for miscarriages, stillbirths, and fetal malformations in female anesthesia care providers, these studies that were performed before the advent of scavenger systems for anesthesia circuits (late 1970s - early 1980s[7]) had documented higher proportions of female offspring in male anesthesia care providers, secondary to occupational exposure to inhalational anesthetics.…”

“…[1] However, reported studies in anesthesiologists related to anesthesia practice and its effects on pregnancy including OSR were performed in the early 1970s and were based on small sample populations. [1–6] In addition to the documentation of higher risks for miscarriages, stillbirths, and fetal malformations in female anesthesia care providers, these studies that were performed before the advent of scavenger systems for anesthesia circuits (late 1970s - early 1980s[7]) had documented higher proportions of female offspring in male anesthesia care providers, secondary to occupational exposure to inhalational anesthetics. [2–5] With scavenger systems becoming standard of care for anesthesia care delivery environments in United States over the last three decades, it is valid to investigate whether these earlier reported effects are still evident in the current anesthesia care provider population.…”

Temporal and spatial trends in the sex ratio at birth in Greece, 1960–2006: exploring potential environmental factors

“…Moreover, and beyond pure demography, the ratio has been suggested as a sentinel environmental health indicator (Davis et al 1998;Jarrell 2002) based on: (a) its recent observed decline in many industrialised countries-including Greece (Grech et al 2003;Mathews and Hamilton 2005;Parazzini et al 1998) (b) increasing concern regarding the wide dispersion in the environment of certain chemicals, known as endocrine disruptors, and their effects on reproductive health (Barlow et al 1999;Jarrell 2002) and (c) certain well-documented cases where accidental or occupational exposure of parents significantly affected the sex of their offspring (de Gomez et al 2002;Grant and Metcalf 2003;Mocarelli et al 2000).…”