Almost a fifth of pregnant women in the UK are clinically obese. Obesity during pregnancy puts both mother and baby at greater risk of almost every medical complication in the book.

One Born: Plus Size Mums follows three morbidly obese pregnant mothers as they, and the professionals who care for them, do all they can to bring their children safely into the world. But not all runs smoothly.

The film follows super-morbidly obese Lucy and her husband Barry, who have been trying for seven years to have children. After losing 20 stone, Lucy fell pregnant with her first child, only to see her weight rise again, putting her and her baby at high risk.

At 21 stone, morbidly obese Jenna is pregnant with her second child. When she met her husband, David, she was a size 10, but thanks to a comfortable lifestyle and two pregnancies, her weight has rapidly risen. A potentially life-threatening condition is discovered and Jenna and David have to face the consequences.

Anne and Graham can't wait to welcome their son into the world and had no idea how much their baby was at risk due to Anne's 19 stone weight, until they attended their first ante-natal appointment. Since then, they have been on a mission to cut down on fast food in the hope that their son will have a safe delivery. But will they be successful?