Call for papers - Reproduction, Technology and Society, a new section in Reproductive BioMedicine Online
Page URL: https://www.bionews.org.uk/page_92290

Air pollution linked to lower IVF success

19 April 2010
Appeared in BioNews 554

Exposure to air pollution has been linked to a lower chance of IVF success, a study has found. Nitrogen dioxide, fine particulate matter and ozone posed a particular risk, according to the researchers from Pennsylvania State University College of Medicine, US.

Dr Richard Legro and colleagues followed 7403 women who were undergoing their first IVF cycle, between 2000 and 2007, at rural, suburban and urban fertility clinics in Hershey, Rockville, Maryland or New York City. They used local air quality monitoring data from the US Environmental Protection Agency to estimate the daily air pollution levels near the women's homes and fertility clinics. They then related the effects of these pollutants at each stage of the IVF cycle and during pregnancy to the women's pregnancy outcomes.

Overall, 36 per cent of the women had a successful pregnancy after their first IVF treatment. Higher levels of nitrogen dioxide near a woman's home or the fertility clinic, and at any stage of the IVF cycle or pregnancy, were always associated with a lower chance of pregnancy and live birth.

Higher levels of ozone at the time of embryo implantation into the womb decreased the chances of a successful pregnancy, but high levels at the time of ovulation were found to increase the chances of pregnancy and live birth. The authors speculated that, because ozone levels are typically high when nitrogen dioxide levels are low, the latter result might reflect the fact that lower nitrogen dioxide levels during ovulation have a positive effect on IVF success rate. In fact, when they analysed the combined effect of nitrogen dioxide and ozone on pregnancy outcomes, the researchers found that nitrogen dioxide still had a strong negative effect, but the effect of ozone was no longer significant.

Higher levels of fine particulate matter (PM2.5) at the fertility clinic site were also associated with lower rates of conception, but not with live birth rates. Larger particulate matter (PM10) and sulphur dioxide did not have an effect on pregnancy outcome.

Other studies have demonstrated a link between exposure to air pollution during pregnancy and risk of preterm birth and low birthrate. By focusing on IVF pregnancies, this study, published in the journal Human Reproduction, was able to link the daily air pollution data to specific stages of the pregnancy process - from ovulation to fertilisation, embryo implantation into the uterus, conception and pregnancy.

Dr Legro stressed that the study didn't demonstrate a mechanism of action of air pollution. Duanping Liao, professor of epidemiology at Pennsylvania State College of Medicine, hypothesised that air pollution might affect pregnancy by causing chronic inflammation in the body or by increasing the risk of blood clotting - factors that the researchers linked to air pollution in their earlier research.

The main source of air pollution is fuel combustion for motor transport, which produces nitrogen dioxide, fine particulate matter, carbon dioxide and other pollutants. Ground-level ozone, the primary constituent of smog, is formed from in a chemical reaction with sunlight from nitrogen dioxide and volatile organic compounds (VOC).

SOURCES & REFERENCES
Air pollution linked to odds of IVF success
National Post |  26 March 2010
Effect of air quality on assisted human reproduction
Human Reproduction |  13 March 2010
Exposure to nitrogen dioxide lowers in vitro fertilization success
Eurekalert |  12 April 2010
Pollutants affect in vitro fertilization
UPI.com |  12 April 2010
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
30 April 2018 - by Eleanor Taylor 
A recent large-scale study has indicated that high levels of air pollution could reduce the chance of pregnancy following fertility treatment...
11 November 2013 - by Dr Rachel Montgomery 
High levels of air pollution are to blame for a distinct drop in semen quality in Shanghai, according to the doctor who runs the city's main sperm bank...
19 November 2012 - by Holly Rogers 
A preliminary study from the National Institutes of Health (NIH), USA, suggests that environmental pollutants including industrial chemicals and pesticides may be impairing human fertility, despite being banned more than thirty years ago....
9 May 2011 - by Dr Kimberley Bryon-Dodd 
Women who attended a mind and body course shortly before undergoing IVF demonstrated increased pregnancy rates compared with those that did not, a US study has found. The findings suggest that stress relief may increase the likelihood of becoming pregnant from IVF....
31 January 2011 - by Dr Lux Fatimathas 
Israeli researchers have shown a correlation between successful IVF (in vitro fertilisation) and 'medical clowning'. In a small-scale study a 'medical clown' was used to entertain women immediately following embryo implantation. A rise in the pregnancy rate was observed in the women subjected to medical clowning compared to controls...
15 March 2010 - by Dr Sophie Pryor 
Acupuncture and Chinese herbal medicine do not provide any benefit to women trying to become pregnant, the British Fertility Society (BFS) has found after reviewing the available evidence. The new guidelines, published in the journal Human Fertility, state that there is 'currently no evidence' that these methods increase the success rate of assisted conception, when used in conjunction with IVF (in vitro fertilisation)....
25 January 2010 - by Harriet Vickers 
Rocking growing embryos during IVF could improve pregnancy rates among women undergoing the procedure, and decrease its risks. Scientists at the University of Michigan, US, have built a device which mimics the movement felt by embryos on their way to the uterus. When they used this during IVF with mouse embryos, they found pregnancy rates were 22 per cent higher compared to those grown statically...
22 October 2009 - by Ben Jones 
A study conducted by researchers at the Harvard Medical School, US, has suggested that consumption of alcohol may be detrimental to chances of success in IVF treatment. Consumption of just six units of alcohol a week by both partners reduced the probability of conception by 26 per cent. The study particularly singled out apparent detrimental effects to drinking white wine in women and drinking beer for the male partners. In those women whose partner dran...
HAVE YOUR SAY
Log in to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions


Syndicate this story - click here to enquire about using this story.