Women who take years to get pregnant are more likely to give birth to unhealthy babies, new research from Finland shows.
Dr Kaisa Raatikainen and colleagues from Kuopio University Hospital also found that these women were at greater risk of having problems during pregnancy and labour, such as developing pregnancy-related diabetes and infections of the membranes surrounding the foetus.
Women take longer to get pregnant as they age. For example, up to 85% of fertile women younger than 35 years old will get pregnant within one year of trying, while just half of women older than 35 will.
Women who have a hard time getting pregnant -- even if they eventually do get pregnant without the help of assisted reproductive technologies (ART) -- are more likely to be obese, to drink alcohol, and to smoke, the Finnish researchers point out in the journal Fertility and Sterility.
How the study was done
They investigated associations between time to pregnancy and pregnancy outcomes for 17 114 pregnancies delivered between 1989 and 2007 at Kuopio University Hospital. None of the women had used ART.
Nearly three-quarters got pregnant within six months, while 12% took six months to a year to conceive, 6% took between 13 months and two years, and about 4% took longer than two years to become pregnant. The longer it took a woman to get pregnant, the researchers found, the more likely she was to have had at least one miscarriage beforehand.
Once the researchers adjusted for factors like a woman's age, whether or not she was married, and whether or not she had previous miscarriages, they found that women who took more than two years to get pregnant were 51 to 64% more likely to have adverse pregnancy outcomes such as premature delivery and giving birth to an unhealthy baby.
The findings suggest, Raatikainen and her colleagues say, that the relationship some studies have found between ART and poor pregnancy outcomes could have something to do with the mother having taken a longer time to conceive. "Thus, concerns about its safety might be put into a new perspective," they wrote. - (Reuters Health, December 2009)