Taking a long time to get pregnant may be linked to minor neurodevelopmental problems in the child, suggests a small study published online in the Fetal & Neonatal Edition of Archives of Disease in Childhood.
This suggests that impaired fertility itself - defined as failing to become pregnant after 12 months - rather than fertility treatment, may be a key factor in any subsequent developmental problems in the child, say the authors.
It is well known that children conceived as a result of fertility treatment are at a higher risk of premature birth and low birthweight, but evidence is beginning to suggest that it may be impaired fertility itself that is the culprit, rather than fertility treatment, say the authors.
They assessed the neurological development of 209 children when they were two years old. All had been born to parents who had struggled to conceive, and most of whom had had fertility treatment.
Domains assessed included movement (fine and gross motor functions), posture and muscle tone, reflexes, and eye-hand coordination (visuomotor function).
Mild neurological problems were evident in 17 (just under 8%) of the children, and were significantly more common among those whose parents had taken longer to conceive.
The time taken to get pregnant among their parents averaged just over four years, but ranged from 1.6 to just over 13 years.
Parents whose children did not have these problems took an average of two years and 8 months to conceive, but ranging from one month to 13 years.
After taking account of influential factors, such as the parents' ages, the analysis indicated that longer time to pregnancy was associated with a 30% increased risk of giving birth to a child with mild neurodevelopmental problems.
"In conclusion, the present data suggest that increased time to pregnancy is associated with suboptimal neurological development," write the authors. "This implies that factors associated with subfertility may play a role in the genesis of neurodevelopmental problems."
Further research will be needed before couples can be counselled accordingly, they add.
[Increased time to pregnancy is associated with suboptimal neurological condition of 2-year olds Online First doi 10.1136/archdischild-2012-303366]