DOCTORS are being encouraged to monitor the weight of expectant mothers more closely with new pregnancy guidelines recommending a discussion about weight be part of every antenatal appointment.

The updated clinical guidelines for pregnancy care recommend several key changes, including giving pregnant women the chance to be weighed at every antenatal visit.

Mothers should be encouraged to monitor their weight gain and each appointment should include a discussion on weight change, diet and exercise.

About 20 per cent of women who gave birth in Australia in 2016 were obese and 26 per cent were overweight.

Women who are overweight or obese are at a higher risk of having a premature baby.

The updated guidelines diverge from the routine testing of vitamin D levels in pregnant women, despite a significant interest in the topic in the past decade.

The authors of a guideline summary, published today by the Medical Journal of Australia, found routine vitamin D testing was not supported by evidence and that the benefits and harms of supplements were not clear.

Lead author Caroline Homer said testing for vitamin D was expensive and supplements involved a further cost for pregnant women.

“While we know that vitamin D deficiency exists, we don’t have good evidence that treating it makes any difference to preg-nancy outcomes and makes any difference to baby outcomes, so it’s really not an effective screening tool,” Professor Homer said.

“We are recommending that women who have particular risk factors are offered screening and that’s particularly women who are covered who don’t get very much sunlight and women who have darker skin.”

It has also been recommended that women are tested for hepatitis C at the first antenatal visit.

Women who are diagnosed with hepatitis C early in their pregnancy can avoid invasive procedures that increase the risk of mother-to-baby transmission.

About 20 per cent of people with chronic hepatitis C remain undiagnosed but after major advances in treatment the virus can now be cured.

Treatment for hepatitis C during pregnancy is not recommended but women who have the virus can start treatment in the postpartum period. This would reduce the risk of liver disease and remove the risk of perinatal infection for later pregnancies.