Australian researchers have found that morning sickness suffered by many women during pregnancy can also increase anxiety levels for dads-to-be.

Morning sickness is not only debilitating for many pregnant women, but can also make expectant dads more anxious, researchers have found.

A survey of 300 Australian dads-to-be showed anxiety levels were significantly higher among those whose partners battled moderate morning sickness, or the more severe hyperemesis gravidarum, which the Duchess of Cornwall is again being treated for ahead of the birth of her third child.

Weighing on the dads were worries about work, family responsibilities and the health of their unborn child, researchers from Edith Cowan University in Perth found.

Lead researcher Julie Sartori said the findings suggested many dads may benefit from increased support from health professionals during pregnancy, particularly those expecting their first baby.

"Professionals would normally focus on the wellbeing of pregnant women, however, engaging the father as well may help relieve reported anxiety and improve outcomes in the long term," she said on Tuesday as the study was published in the Journal of Psychosomatic Obstetrics & Gynecology.

Nausea and vomiting occurs in 70 to 90 per cent of pregnancies, with hyperemesis gravidarum affecting about three per cent of women.

Half of all pregnant women usually report feeling better by the 14th week of pregnancy and 80 per cent by week 22.

The researchers said while health professionals help women cope with morning sickness, there was little data about the impact it has on fathers.

The 300 men who took part in the study were asked about how aware they were of their partner's morning sickness and how depressed and anxious the condition made the dads feel.

Eighty two per cent of men said they were aware whether their partner experienced morning sickness, with 30 per cent describing the condition as mild, 37 per cent moderate, and 13 per cent severe.

While the researchers found no significant difference in rates of depression among men whose partners had morning sickness and those whose did not, rates of anxiety were significantly higher for expectant dads whose partners had moderate and severe morning sickness.

Many of the anxious dads reported that their work had been disrupted by their partner's morning sickness, with some being forced to take time off to care for their partner.

Others experienced strong feelings of frustration and helplessness, as well as concerns about their unborn child's development and the depressed state of their partner while battling morning sickness.

Australian readers seeking support and information about depression can contact Lifeline on 13 11 14.