科研人員報告說，在一年的某些時間受孕的女性可能容易出現(xiàn)早產(chǎn)等新生兒健康方面的問題。大量研究已經(jīng)把出生的季節(jié)與身高,、智商,、心理健康、收入以及預期壽命等多種成年人的結果聯(lián)系了起來,。然而,，近來的發(fā)現(xiàn)提示，與母親的社會經(jīng)濟狀態(tài)相比,，出生季節(jié)可能不重要,，因為年輕、貧窮,、受教育不足,、未成年和未婚的母親傾向于在與最差的成年結果有關聯(lián)的季節(jié)分娩,。Janet Currie和Hannes Schwandt通過比較紐約市,、新澤西和賓夕法尼亞州的647050名母親的子女——總共生產(chǎn)次數(shù)超過140萬次——從而探索了受孕季節(jié)與出生時的健康的關系。這組作者報告說,，這項分析發(fā)現(xiàn)在5月受孕的新生兒比在一年的其他月份受孕的新生兒的早產(chǎn)率要高出10%,，這可能反映了1月和2月季節(jié)性流感病例的劇增，而此時這些女性懷孕接近足月,。此外,，在夏季月份受孕的新生兒傾向于比其他新生兒重大約8到9克，這很可能是由于懷孕體重增加的季節(jié)性模式,。這些結果無法通過諸如吸煙或婚姻狀態(tài)等因素加以解釋,。這組作者提示，這些發(fā)現(xiàn)可能為諸如鼓勵孕婦接種流感疫苗的公共政策提供信息,。（生物谷 Bioon.com）
生物谷推薦的英文摘要
PNAS 10.1073/pnas.1307582110
Janet Currie and Hannes Schwandt
Within-mother analysis of seasonal patterns in health at birth
A large literature describes relationships between month of birth, birth weight, and gestation. These relationships are hypothesized to reflect the causal impact of seasonal environmental factors. However, recent work casts doubt on this interpretation by showing that mothers with lower socioeconomic status are more likely to give birth in months that are associated with poorer birth outcomes. Seasonality in the numbers of conceptions in different months can also induce a mechanical correlation between preterm birth and month of birth. This paper analyzes the seasonality of health at birth using a large sample of 647,050 groups of US siblings representing 1,435,213 children. By following the same mother over time, we eliminate differences in fixed maternal characteristics as an explanation for seasonal differences in health at birth. We find a sharp trough in gestation length among babies conceived in May, which corresponds to an increase in prematurity of more than 10%. Birth weight conditional on gestation length, however, is found to be strongly hump-shaped over the year, with 8–9 additional g for summer conceptions. We examine several potential mechanisms for explaining seasonality in birth outcomes that have generally been dismissed in the literature on seasonality in rich countries, notably disease prevalence and nutrition. The May trough in gestation length coincides with a higher influenza prevalence in January and February, when these babies are nearing full term, whereas the hump shape in birth weight is associated with a similar pattern in pregnancy weight gain.
