US EPA

664487 

Journal Article 

High ambient temperature and the risk of preterm delivery 

Basu, R; Malig, B; Ostro, B 

2010 

Yes 

American Journal of Epidemiology
ISSN: 0002-9262
EISSN: 1476-6256 

172 

10 

1108-1117 

English 

20889619 

10.1093/aje/kwq170 

WOS:000283918700002 

With temperatures expected to increase because of climate change, it is essential to study the health outcomes of elevated temperature in vulnerable populations, such as expectant mothers. In this study, the authors estimated the association between heat and humidity, as measured by apparent temperature, and preterm delivery. They conducted a case-crossover analysis of almost 60,000 births spanning 16 counties in California that occurred from 1999 to 2006 between May and September. The authors identified cases of preterm birth from a state registry of births, which were combined with meteorologic and air pollution monitoring data based on residential zip code. High ambient temperature was significantly associated with preterm birth for all mothers, regardless of maternal racial/ethnic group, maternal age, maternal education, or sex of the infant. Results indicated that an 8.6% increase (95% confidence interval: 6.0, 11.3) in preterm delivery was associated with a 10°F (5.6°C) increase in weekly average (lag06) apparent temperature. Greater associations were observed for younger mothers, blacks, and Asians. These associations were independent of air pollutants. Given the significant associations for apparent temperature and preterm delivery found in this study, more large-scale studies of temperature and preterm delivery are warranted. 

air pollution; California; hot temperature; pregnancy outcome; premature birth; temperature