Research says working mums of two are twice as stressed as working women with no kids

And nobody was surprised.

Look – anyone will tell you that being a mum is pretty full-on. Not just the actual mothering someone bit, although that can be pretty darn hectic too. No, I think what adds the most stress for many of us is the so-called 'mental load' – as in; all the things we mums need to keep on top of – regardless of how demanding our actual day job is as well. I am talking birthday parties and voluntary contributions and play dates and dentist appointments and homework projects and bake sales and GAA camps and ballet lessons and the shopping and the dinner plans and the family Christmas card list. And then some. Really – it should come as no surprise that working mums are stressed. The question is – how much stress are we really talking about? A new study might just offer some insight: According to researchers from the U.K., among women working full-time, those with one child are 18 percent more stressed out than those without kids. However, ladies – with an additional child, the amount of stress among mums who work full-time jumps to 40 percent, compared to women working full-time who don't have kids, the Independent reports. However, there is a lot to be said for a bit of work-life balance, as the study, which appears in the journal Sociology, also found that mums with two kids who worked reduced hours actually had chronic stress levels that were 37 percent lower than the stress levels of mums who worked inflexible hours. Phew. For the study, researchers analyzed data from 6,000 participants across the U.K. who were part of the country's Household Longitudinal Study, and examined their working life, hormone levels, blood pressure and experiences with stress, according to the Independent. To measure participants' stress levels, they evaluated whether each exhibited any of the 11 markers in five biological systems related to chronic stress – the neuroendocrine system, the metabolic system, the immune and inflammatory systems, the cardiovascular system and the anthropometric system, which involves measurements of the human body. Researchers also controlled for lifestyle factors like women's ages, income and ethnicity, which could influence their findings. According to the Independent, the American Institute of Stress identifies chronic stress symptoms as irritability, anxiety, depression, headaches and insomnia. Based on the findings, researchers believe there is a link between work-family conflict and increased psychological strain—with higher levels of stress and lower levels of well-being. “Repeated stressful events arising from combinations of social and environmental stressors and major traumatic life events result in chronic stress, which in turn affects health,” they wrote. What's more, researchers say parents of young children are most at risk of work-family conflict negatively affecting their stress reactions if their work conditions, like working long hours, aren't flexible to their family demands. Giving workers flexible hours, however, may help them achieve work-life balance.