Featured Research

from universities, journals, and other organizations

Exposure to nitrogen dioxide lowers in vitro fertilization success

Date:
April 13, 2010
Source:
Penn State
Summary:
Exposure to an increased level of air pollutants, especially nitrogen dioxide, has been associated with lower likelihoods of successful pregnancy among women undergoing in vitro fertilization, according to a team of fertility researchers.

Exposure to an increased level of air pollutants, especially nitrogen dioxide, has been associated with lower likelihoods of successful pregnancy among women undergoing in vitro fertilization, according to a team of fertility researchers.

The team examined the outcomes of the first pregnancy attempt of 7,403 women undergoing IVF at Penn State Milton S. Hershey Medical Center, Hershey, Pa.; Shady Grove Fertility, Rockville, Md.; and Columbia University College of Physicians and Surgeons, New York, N.Y. They conducted their observations over a seven-year period from 2000 to 2007.

"Numerous studies have consistently shown a relationship between air pollution and human health, ranging from mortality, cardiovascular disease and other chronic conditions," said Duanping Liao, Ph.D., professor of epidemiology and vice chair department of public health sciences, Penn State College of Medicine. "In the process of searching for the mechanisms responsible for the above associations, we, and others, have reported significant links between air pollution and inflammation and increased blood clotting. These intermediate factors are also associated with reproductive health."

The IVF population was chosen, as it is a well-controlled and timed process to investigate the association of air pollution and human reproductive effects.

Burning of fossil fuels and diesel engine combustion produces nitrogen dioxide and fine particles. Researchers looked at those pollutants along with ozone, the gas involved in smog formation. While the effects of declining air quality on IVF success are variable and pollutant-dependent, elevated exposures to nitrogen dioxide and fine particles were consistently associated with lower success rates of pregnancy.

Researchers looked at the effects of pollution particles both individually -- single pollutant model, and with other particles -- multi-pollutant model. For the single pollutant model, exposure to ozone appeared to have a positive association with a successful birth if the exposure was before the embryo culture or embryo transfer. Researchers theorize that higher ozone levels indicate lower nitrogen dioxide levels, which would show better pregnancy outcomes. In addition, for the multi-pollutant model, the "positive" effects of ozone were diminished with the addition of nitrogen dioxide. In contrast, after adjusting for ozone, higher nitrogen dioxide exposures consistently associated with the lower success rate, regardless of which indictor was used -- positive pregnancy test, clinically confirmed intrauterine pregnancy or live birth.

These findings may be useful in studying the adverse effects of air pollution on human reproduction in general.

"Since IVF is a well controlled and highly timed process, we have a much better handle on the assessment of the time of exposures to elevated air pollutants in relationship to fertilization, pregnancy, and delivery," Liao said. "Therefore, the IVF population coupled with detailed assessment of air pollution exposures may provide us an ideal situation to investigate the potential health effects of air quality on human reproduction."

Air pollutant concentration data for the study period came from the U.S. Environmental Protection Agency. The researchers calculated daily pollution concentrations for each patient during the entire in vitro cycle and pregnancy. They calculated varying periods of air quality exposure for average daily concentrations at the patient's home during four stages of IVF and at the IVF clinic during fertilization and embryo transfer.

The researchers published their results in Human Reproduction. The Pennsylvania Department of Health in part funded this research using tobacco settlement funds.

Other researchers on this study were Xian Li, Ph.D., postdoctoral fellow, public health sciences, and Richard S. Legro, M.D., and William C. Dodson, M.D., professors, obstetrics and gynecology, all at Penn State College of Medicine; Mark V. Sauer, M.D., Columba University College of Physicians and Surgeons, department of obstetrics and gynecology; Gilbert L. Mottla, M.D., and Kevin S. Richter, Ph.D., Shady Grove Fertility.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Journal Reference:

  1. Richard S. Legro, Mark V. Sauer, Gilbert L. Mottla, Kevin S. Richter, Xian Li, William C. Dodson, and Duanping Liao. Effect of air quality on assisted human reproduction. Human Reproduction, 2010 DOI: 10.1093/humrep/deq021

Cite This Page:

Penn State. "Exposure to nitrogen dioxide lowers in vitro fertilization success." ScienceDaily. ScienceDaily, 13 April 2010. <www.sciencedaily.com/releases/2010/04/100412111631.htm>.
Penn State. (2010, April 13). Exposure to nitrogen dioxide lowers in vitro fertilization success. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2010/04/100412111631.htm
Penn State. "Exposure to nitrogen dioxide lowers in vitro fertilization success." ScienceDaily. www.sciencedaily.com/releases/2010/04/100412111631.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins