Scotland is falling behind other parts of the UK in caring for the mental health of pregnant women and new mothers, according to an expert group.

The panel, which includes health, charity and education professionals, has called for more investment to tackle a "fragmented and inadequate" level of support.

Research shows that around 20% of women suffer from anxiety and depression during pregnancy and in the first postnatal year, with the costs of not addressing these problems estimated to be £8.1 billion annually.

The group has described the help available as a "postcode lottery" with just five out of 14 health boards having a community perinatal mental health team.

A call-to-action urges the Scottish Government to use an estimated £7.5 million in consequentials received through the Barnett Formula - the mechanism for distributing central funds between the nations of the UK - to address gaps in care.

They point out that while the UK Government has ring-fenced spending for perinatal mental health services in England and the Welsh Government has announced investment of £1.5 million to improve community-based provision, the money has not been ring-fenced in Scotland.

The group also calls for a "nationally coordinated, systematic approach" by health boards to develop specialist services.

Elaine Clark, chair of Maternal Mental Health Scotland, said: "We're pleased that perinatal mental health has been identified as a priority for the new National Mental Health Strategy for Scotland.

"We're committed to working with the Government and health boards to improve and develop the services that are badly needed. Investment in community services nationally would tackle stigma and remove barriers to women accessing safe and effective care."

Matt Forde, national head of service for NSPCC Scotland, added: "The link between maternal mental health and child well-being is well documented, and yet Scotland is still not doing enough to support the mental health of pregnant women and new mums.

"We want to see national clinical guidelines implemented in full, along with specific investment like we have seen in England and Wales. Investing in perinatal mental health can help protect two generations at once."

Mental Health Minister Maureen Watt said: "It is a priority for the Scottish Government to ensure there is effective support for perinatal mental health problems in Scotland.

"Perinatal mental health is a key area of focus in the forthcoming mental health Strategy. Early intervention is crucial to our 10-year vision to improve mental health in Scotland.

"In line with a recommendation from the Mental Welfare Commission, the Scottish Government is establishing a managed clinical network for perinatal mental health.

"Work has already been progressing on the creation of a new network and it is currently progressing through the approval process at NHS National Services Scotland. We are clear that we want it to be approved and implemented as soon as possible."