A new study from the University of Michigan reveals that 'baby weight' may not actually be the reason we can't get back to pre-pregnancy form - the demands of motherhood may be to blame.

They say it takes just as long to take off the weight gained during pregnancy as it did to put it on, meaning mothers should not expect to be back to their pre-pregnancy weight for almost a year after giving birth. Many women find that pregnancy weight seems to hang on much longer.

The study looked at over 32,000 women who had delivered one to four children in Wisconsin. The results show that there's not much difference in cumulative weight gain in women one or two years after birth when compared to women who had not given birth.

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In fact, lead researcher of the study and associate professor of nursing at the University of Michigan, Olga Yakusheva, said that while the weight gain differences in women of similar age who had children compared to those who had not was not necessarily significant, women with children gained weight at a faster rate than women who had not given birth.

The research team looked at weight patterns of both sets of women and then with scientific method, calculated what weight patterns would have been if the women had not given birth. They found that the average woman who did not give birth gained 1.94 pounds a year compared to an annual 2.89 pound weight gain in women who had children.

Yakusheva believes that mothers tend to gain weight faster, and have a harder time taking it off because of the demands of motherhood. They tend to put the needs of their children first, not making enough time for exercise and self care.

Related: Self-Care for Moms: 10 Ways to Stay Happy (and Sane!)

The researchers want it to be clear that age progression certainly plays a part in a woman's annual health gain, and according to Jennifer Temple, associate professor at the University of Buffalo's School of Public Health and Health Professions, a woman should not feel the requirement to return to pre-pregnancy weight.

Temple says that returning to a weight that would factor in metabolic changes that are associated as we age (approximately 2-3 pounds a year, on average) is more realistic and would take the pressure off many women who feel they have to get back into their 'skinny' jeans.

Photo Credit: Jake Guild/flickr