By Nneka Nwogwugwu
The Centre for Reproductive Medicine at Peking University Third hospital in China, has revealed in a study that air pollution has a significant effect on reproduction as it increases the risk of infertility.
Qin Li, who led the infertility research, said prospective parents should be concerned about air pollution.
The report which was published on Wednesday on the Guardian Uk, revealed that an analysis of 18,000 couples in China found that those living with moderately higher levels of small-particle pollution had a 20% greater risk of infertility, defined as not becoming pregnant within a year of trying.
“Numerous studies have noted that air pollution is associated with lots of adverse pregnancy events.
“Approximately 30% of infertile couples have unexplained infertility,” Li and colleagues wrote, noting that age, weight and smoking were well-known factors. “[Our study] indicates that small-particle pollution could be an unignorable risk factor for infertility.
‘’The pollution levels in China are relatively high, but harmful effects have been reported on reproduction at much lower levels.
“So clearly poor air quality impacts the reproductive system in general,” Li said.
The study design did not enable the scientists to determine how air pollution might damage fertility, but pollution particles are known to cause inflammation in the body, which could damage egg and sperm production, the scientists said.
According to the study, another recent study of 600 women attending a US infertility clinic found that increased exposure to air pollution was associated with a lower number of maturing eggs in the ovaries.
Prof Mireille Toledano at Imperial College London, UK, said new research on this important topic was very welcome as there were not many previous studies.
She said lower levels of air pollution might affect infertility, but that more research was needed.
The research, published in the journal Environment International, was based on data from interviews and questionnaires from 18,571 couples who were part of the large China Fertility Survey of Married Women.
In China, women are required to register with the authorities before attempting to become pregnant, enabling the researchers to request information from all women who were aiming to conceive.
The researchers found that women exposed to small particle pollution that was 10 micrograms per cubic metre higher over a year had a 20% greater risk of infertility.
The results also showed that the proportion of women not becoming pregnant after 12 months of trying rose from 15% to 26% when comparing the quarter exposed to the lowest pollution with the quarter suffering the highest.
The researchers took account of other factors including age, weight, income, smoking, alcohol drinking, and exercise levels.