Melnikov Vladimir N
Institute of Physiology, Siberian Branch of Russian Academy of Medical Sciences, Novosibirsk, Russia.
Twin Res Hum Genet. 2012 Feb;15(1):133-7. doi: 10.1375/twin.15.1.133.
Mechanisms underlying effects of physical factors on twin births are unclear. The present work studied an association between monthly and yearly multiple birth rates (MBRs) in the Novosibirsk region, south-west Siberia, in relation to solar activity (sunspot numbers) and geomagnetic activity (Ap index) from 1957 to 2008. The difference was verified by comparing the yearly MBR observed in 3-year peaks (M = 7.36, SD = 0.33 per 1,000 births) and 3-year troughs (M = 8.10, SD = 0.31 per 1,000 births, p < .001) of an 11-year solar cycle. An inverse correlation (r = -.60, p < .001) was found between sunspot numbers and MBR for a lag of 1 year. Cross-spectral analysis of a 52-year time series established a common signal with the period of 10.5 years, as well as high coherence (K(2) = 0.87). The multiple regression analysis revealed a significant interaction of solar and geomagnetic effects upon the frequency of twin maternities. The results show that elevated solar activity within the 11-year cycle coinciding with the time of conception inhibits multiple births in a manner depending on geomagnetic activity. It is hypothesized that the likely mechanism underlying the association is early fetal loss induced by solar radiation/flux and its terrestrial mediators.
物理因素对双胞胎出生影响的潜在机制尚不清楚。本研究调查了1957年至2008年期间，位于西伯利亚西南部新西伯利亚地区的月和年多胞胎出生率（MBR）与太阳活动（太阳黑子数）和地磁活动（Ap指数）之间的关联。通过比较11年太阳周期中3年峰值（M = 7.36，标准差=每1000例出生0.33）和3年谷值（M = 8.10，标准差=每1000例出生0.31，p <.001）时观察到的年MBR，验证了差异。发现太阳黑子数与滞后1年的MBR之间存在负相关（r = -.60，p <.001）。对52年时间序列的交叉谱分析确定了一个周期为10.5年的共同信号，以及高相干性（K(2)= 0.87）。多元回归分析显示，太阳和地磁效应在双胎妊娠频率上存在显著相互作用。结果表明，在11年周期内与受孕时间一致的太阳活动增强，以一种依赖地磁活动的方式抑制多胞胎出生。据推测，这种关联的潜在机制可能是太阳辐射/通量及其地球介质引起的早期胎儿丢失。
