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A new perspective
An American team from the National Institute of Environmental Health Sciences in North Carolina analyzed data on 782 couples from seven European cities, and concluded that even when the woman was aged between 35 and 39, fewer than one in 10 failed to conceive after two years -- unless the male partner was over 40.

Lead investigator Dr David Dunson suggested that couples should be patient and doctors should not intervene too fast with assisted reproductive techniques unless there are known reasons for a couple not conceiving naturally within a year. He told the annual conference of the European Society of Human Reproduction and Embryology that recent research undertaken by his team showed that fertility in women started to decline as early as the late 20s, and, for men, from their late 30s. However, this was due primarily to declines in the per menstrual cycle conception rate, and not to an increase in the proportion of couples unable to achieve an unassisted pregnancy. Now, his team has extended their research using data from the European Fecundability Study to see what the implications are for fertility rates overall.

Age matters
"On average, the time to pregnancy increases with the age of the woman," says Dr Dunson. "The percentage failing to conceive within a year ranged from eight percent for 19 to 26-year-olds; to 13 to 14% for 27 to 34-year-olds; to 18% for 35 to 39-year-olds." However, regardless of age, most of the women who failed to conceive within the first twelve cycles did conceive at some point during the next twelve. Only three percent of 19 to 26-year-olds, six percent of 27 to 34-year-olds, and nine percent of the women who were 35 to 39 years old failed to conceive in the second year, provided the male partner was aged under 40.

Starting in the late 30s though, male age was also important: it meant that the percentage of failures after one year for women aged 35 to 39 rose from 18 percent to 28 percent, if the male partner was over 40. After the second year, the figure was nine percent with male partners under 40, and 16 percent with male partners over 40."

Hold that thought
Dr Dunson said there were clear increases with age in the number of menstrual cycles needed to achieve pregnancy and in the probability of being classified as "clinically infertile" -- a definition applied after a year of trying to conceive. But, their research had clearly shown that among outwardly healthy couples with no known conditions associated with infertility, most who failed to conceive naturally within the first year will conceive naturally in the second year -- regardless of age.

"In the absence of clinical indicators of infertility in addition to a long time to pregnancy, it may be appropriate to delay assisted reproduction until the couple has failed to conceive naturally in 18 to 24 months," says Dr Dunson. "There is a large amount of normal variability in fertility, and many couples having below average, but normal fertility may fail to conceive within a year." This is especially true for "older" couples, many of whom do not conceive within the first year, but are successful in the second year.

What does this mean to you? Dr Dunson says it is important for doctors to avoid recommending assisted reproduction too soon, due to well-documented side effects. He suggests, "Fertility treatment, such as IVF and ICSI, can result in an increased risk of multiple pregnancies, pregnancy complications, low birth weight, major birth defects and long-term disability among surviving infants." He also noted that the chance of success with ART (assisted reproductive technologies, e.g. fertility treatments) also decreases with age, while the side effects become more prevalent.