Koshy Gibby, Delpisheh Ali, Brabin Loretta, Attia Eman, Brabin Bernard J
Child and Reproductive Health Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.
Ann Hum Biol. 2010 Nov;37(6):789-800. doi: 10.3109/03014461003742803. Epub 2010 Jun 14.
A recent decline in the male:female (M:F) sex ratio may relate to pregnancy cigarette smoke exposure.
To assess trends and cigarette exposure dose-response effects on the sex ratio.
A retrospective analysis was carried out of deliveries at the Liverpool Women's Hospital between 1998 and 2003, and of deliveries reported in community surveys from the same area in 1998 and 2006.
For the hospital sample, the M:F sex ratio was 1.14 if no parent smoked, and 0.77 when both parents smoked during the mother's pregnancy (p < 0.001). Heavy maternal smokers (>10 cigarettes per day) were more likely to deliver a female baby than light smokers (p < 0.001). Smoking was associated with increased likelihood of female birth controlling for birth year, socio-economic status, alcohol exposure, maternal haemoglobin and body mass index (adjusted OR: 1.41, 95% CI 1.12-1.92, p < 0.001). In the community sample controlling for socio-economic status the ratios were 1.13 (95% CI 1.03-1.24, p = 0.015) in 1998 and 1.31 (95% CI 1.16-1.48, p < 0.001) in 2006. Secular trends showed decreasing ratios in hospital and community samples for both smokers and non-smokers.
Pregnancy cigarette smoking increased the proportion of female births with evidence for a dose-response association.
近期男女性别比下降可能与孕期接触香烟烟雾有关。
评估性别比的趋势以及香烟暴露剂量反应效应。
对1998年至2003年利物浦妇女医院的分娩情况，以及1998年和2006年同一地区社区调查中报告的分娩情况进行回顾性分析。
在医院样本中，如果父母均不吸烟，男女性别比为1.14；如果母亲孕期父母双方均吸烟，则为0.77（p<0.001）。母亲重度吸烟者（每天>10支烟）比轻度吸烟者更有可能产下女婴（p<0.001）。在控制出生年份、社会经济地位、酒精暴露、母亲血红蛋白和体重指数后，吸烟与生女婴的可能性增加有关（调整后的比值比：1.41，95%置信区间1.12 - 1.92，p<0.001）。在社区样本中，控制社会经济地位后，1998年的性别比为1.13（95%置信区间1.03 - 1.24，p = 0.015），2006年为1.31（95%置信区间1.16 - 1.48，p<0.001）。长期趋势显示，医院和社区样本中吸烟者和非吸烟者的性别比均呈下降趋势。
孕期吸烟增加了女婴出生比例，且存在剂量反应关联的证据。
