For many women, body weight can be a major concern when dealing with infertility. Weight loss is often recommended for women with obesity who have had difficulties conceiving.  But what factors can influence the success of a pre-conception lifestyle intervention?



Many factors have been associated with successful weight loss intervention, including higher motivation and positive body image. But these interventions often show only modest changes, and non-completion rates reduce the success of treatment.

However, women who are in a pre-conception stage may be more likely to act on diet and lifestyle advice. This could be because of the motivation to protect the health of a future child. So researchers designed a study to investigate the influence of a lifestyle intervention in pre-conception weight loss, including the factors that supported success.


The study

A randomised control trial was designed to explore the effects of a preconception lifestyle-modification program in women with obesity and infertility. Over 6 months, 289 of the participants underwent the intervention, which included dietary counselling, physical activity and behavioural modification. The main aim of the intervention was 5-10% weight loss.

Researchers defined a successful lifestyle change as ≥5% weight loss and/or BMI ≤29. They monitored weight loss in kilograms, changes to energy intake and changes to physical activity levels. Participants were also assessed on their stage of change towards weight loss and physical activity. The 5 stages for change are pre-contemplation (1), contemplation (2), preparation (3), action (4) and maintenance (5). A higher number indicates a higher stage of change.

For this study, the researchers used data from the control trial to identify which factors supported successful completion of the program. For the purpose of this research, participants who did not complete the full 6 month program due to missing appointments. However, for women who lost sufficient weight loss before the full 6 months or fell pregnant within the period, data was still included.


The findings

Of the 289 participants, 119 reached the requirement for a successful completion within the 6-month period. On average, the women lost 5.3kg. For those who achieved the target, there were several factors that were significantly associated. A lower BMI, lower waist circumference, lower highest weight over the previous 10 years and no previous weight loss support from a dietitian were all associated with successful weight loss.

Some other relationships were noted. Women with an older partner had a higher energy intake. A higher stage of change towards exercise was associated with higher number of daily steps. A high stage of change towards losing weight was associated with completion of the program.



The research team concluded that factors such as no previous dietetic support and high stage of change towards weight loss and physical activity were associated with program completion and positive changes in behaviour.

More research is required to confirm the relationship between these factors and pre-conception weight loss programs. However, it can help to identify women with obesity and infertility who are more likely to benefit from a lifestyle intervention. If a woman does not display these characteristics, alternative approaches may need to be considered.



Karsten, M.D., van Oers, A.M., Groen, H., Mutsaerts, M.A., van Poppel, M.N., Geelen, A., van de Beek, C., Painter, R.C., Mol, B.W., Roseboom, T.J. and Hoek, A., 2018. Determinants of successful lifestyle change during a 6-month preconception lifestyle intervention in women with obesity and infertility. European journal of nutrition, pp.1-13.