More than two in three GP practices are experiencing increased demands for postnatal services, according to a study.
Union chiefs say that the figures, from Independent Nurse magazine, highlight the impact caused by increasing cutbacks to health visitor posts.
The survey showed that 71% of GPs had seen an increase in young mothers seeking help with problems such as postnatal depression, sleep disorders and feeding issues.
Unite, of which the Community Practitioners' and Health Visitors' Association is a part, said the latest NHS workforce statistics reveal that a fulltime health visitor job is lost every 27 hours.
The union said that some GPs have complained at feeling ill-qualified to offer young mothers advice, while others warned they could not fill the health visitors' child protection role.
Unite's Dr Cheryll Adams said: "We welcome the new GP findings in as much that it gives further evidence to our campaign to restore the UK's health visiting service for the benefit of families and communities.
"We are unsurprised by the effects of health visitor cuts on GP workloads with young families, as this was predicted four years ago when the serious cuts started.
"Health visitors also started to be moved out of GP surgeries to work in neighbourhood-based teams. This trend has made the vital communication between doctors and health visitors more difficult."