Why Duchess of Cambridge has a bigger bump in third pregnancy

Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge. Photo / Getty Images

She's maintained an impeccably streamlined figure, sporting a neat and tidy bump each time while expecting Prince George and Princess Charlotte.

And while this pregnancy is no exception, the Duchess of Cambridge, 36, is sporting a comparably bigger baby bump ahead of giving birth next month than she was at eight months pregnant with her first two children, reports the Daily Mail.

The Duchess of Cambridge yesterday, who is eight months pregnant with her third child. Photo / Getty Images

Photos show how the Duchess barely looked pregnant in the late stages of her previous pregnancies, however the royal has displayed a blooming figure during her recent official engagements.

The Duchess of Cambridge when she was eight months pregnant with Princess Charlotte in March 2015. Photo / Getty Images

According to Aly Dilks, a former midwife, who is Clinical Director at The Women's Health Clinic, said that most women who have given birth twice before will have bigger bumps in subsequent pregnancies.

"Essentially, each pregnancy will have its own differences and similarities but we do expect ladies to have bigger babies the more children they have," she told Femail.

Kate's adorable eight month belly bump. Photo / Getty Images

This is mainly due to the body simply knowing what it needs to do in terms of making space for the new arrival, and that is has become adept at making sure the baby is adequately nourished.

"During your first pregnancy the body uses hormones to make changes to accommodate the baby.

"As your rib cage widens and your uterus expands, it can take time to establish a real 'bump'.