Seasonality of fetal trisomy 21--have ambient air pollutants played a role?
OBJECTIVE
To examine the seasonality of fetal trisomy 21 and its relationship with ambient air pollutants.


METHODS
The averaged incidence by month-of-conception of the 113 cases (2002-2009) in our registry was correlated with month of conception and monthly ambient levels of nitrogen oxides (NOx, NO and NO2), sulfur dioxide, carbon monoxide, and ozone as reported by the Hong Kong Environmental Protection Department at the month of, and four-week after, conception.


RESULTS
The incidence was highest in February (3.45/1000 births) and lowest in October (1.28/1000 births), and showed a significant difference (p = 0.003) and positive correlation (p = 0.003) from winter to autumn. It was also correlated with NO (p = 0.017) and inversely with ozone (p = 0.014) at conception.


CONCLUSIONS
Seasonal variation in incidence of fetal trisomy 21 was correlated with ambient levels of nitric oxides and ozone. The role of environmental pollutants on fetal aneuploidy warrants further investigation.
Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong , Prince of Wales Hospital , Hong Kong and.
Man-Kin
MK
Chung
Terence T
TT
Lao
Yuen-Ha
YH
Ting
Tze-Wai
TW
Wong
Tak-Yeung
TY
Leung
D000328:Adult; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D002248:Carbon Monoxide / Q000032:analysis / Q000633:toxicity; D004314:Down Syndrome / Q000453:epidemiology* / Q000209:etiology*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D015994:Incidence; D009569:Nitric Oxide / Q000032:analysis / Q000633:toxicity; D010126:Ozone / Q000032:analysis / Q000633:toxicity; D011247:Pregnancy; D012042:Registries; D012621:Seasons
D000393:Air Pollutants; D009569:Nitric Oxide; D010126:Ozone; D002248:Carbon Monoxide
Air pollution; seasonality; trisomy 21