Research into eating disorders and fertility reveals mixed picture

Eating disorders are known to cause disruption to a woman's menstrual cycle, with substantial weight loss leading to hormonal changes that might prevent ovulation, but so far little research has been carried out into how eating disorders might affect fertility.

A team at King's College London and UCL investigated a group of 11,088 pregnant women from the Avon area of the UK, with women asked to complete questionnaires at 12 and 18 weeks gestation. Women with lifetime anorexia and bulimia were compared to the group as a whole to assess the impact of their eating disorder on attitudes to fertility and pregnancy.

Of the total number of women, 171 (1.5%) had anorexia at some point in their life, 199 (1.8%) had bulimia and an additional 82 (0.7%) had suffered from both conditions. The remaining 10,636 (96%) formed the general population comparison group.

The survey revealed that a higher proportion of women (39.5%) with a history of anorexia and bulimia took longer than six months to conceive compared to the general population (25%). However, they were no more likely to take longer than 12 months to conceive than the general population. The study found that women with anorexia and bulimia were more than twice as likely (6.2%) than the general population (2.7%) to have received treatment or help to conceive their current pregnancy.

However, when asked at 18 weeks gestation, women with anorexia were more likely to report that their current pregnancy was unintentional. In this group of women 41.5% said their pregnancy was unplanned compared to 28.6% of women in the general population.

The majority of women reported feeling overjoyed or pleased when they discovered that they were pregnant (71%). However, eating disorders were linked to negative feelings about pregnancy. Further analysis has shown that women with anorexia and bulimia were more than twice as likely (9.8%) than the general population (3.8%) to report feeling unhappy when they found out they were pregnant.

Lead author, Abigail Easter, from the Institute of Psychiatry at King's College London, said:

"This research highlights that there are risks to fertility associated with eating disorders. However, the high rates of unplanned pregnancies in women with a history of anorexia suggest that women may be underestimating their chances of conceiving.

"Pregnancy can be a difficult time for women with eating disorders and this is the first time feelings about pregnancy have been looked at amongst this group of women.

"Women planning a pregnancy should ideally seek treatment for their eating disorder symptoms prior to conception and health professionals should be aware of eating disorders when assessing fertility and providing treatment for this."

Dr Nadia Micali, Institute of Child Health, UCL and lead investigator added:

"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 antenatal and postnatal care they will need."

Professor Philip Steer, BJOG editor-in-chief said:

"Eating disorders have important clinical consequences, especially in women. This research shows that more women with eating disorders are unprepared for pregnancy and will therefore require more support during the antenatal and postnatal period."

More information: Easter A, Treasure J, Micali N. Fertility and prenatal attitudes towards pregnancy in women with eating disorders: results from the Avon Longitudinal Study of Parents and Children. BJOG 2011; DOI: 10.1111/j.1471-0528.2011.03077.x .

Provided by King's College London