Research has indicated that women with a history of eating disorders could take longer to get pregnant.
A study of more than 11,000 women by experts from King's College London and University College London found that 39.5% of those with a history of anorexia and bulimia took more than six months to conceive.
This compared with 25% of women in the general population.
Meanwhile, 6.2% of women with a history of eating disorders needed treatment to help them conceive, compared with 2.7% of women who did not suffer from any such affliction.
Female anorexia and bulimia sufferers were, however, no more likely to take longer than a year to conceive than other women.
The study was published in BJOG: An International Journal of Obstetrics and Gynaecology.
Dr Nadia Micali, from the Institute of Child Health at University College, said: "Health professionals are often unaware of the effects of eating disorders on pregnancy and fertility.
"Women with a history of anorexia for example are more likely to have unplanned pregnancies.
"This has now been replicated in three large studies and has important repercussions on the level of ante-natal and postnatal care they will need."