Pregnant women in Galway face a wait of up to 20 weeks for their first scan.
HSE West has confirmed the five-month wait, although it says an earlier appointment may be given if there is an indication of an underlying medical condition.
Last week it emerged that public patients attending Our Lady of Lourdes Hospital in Drogheda may have to wait until the 20th week of their pregnancy to see a consultant obstetrician because of pressures on staff.
Medical experts such as Prof John Bonar, a member of the task force overseeing maternity services in the northeast, have warned that women should ideally see their doctor at 12-14 weeks.
Women throughout the State are being encouraged to attend obstetricians early as certain categories of patient may be at risk because of undue delay.
A statement from HSE West said: "First ante-natal appointments at University College Hospital Galway are generally given between 16 and 20 weeks gestation. An earlier appointment may be given if there is an indication of an underlying medical condition or based on previous obstetric history.
"In an instance where a first appointment is given after 20 weeks, this is usually due to when the booking letter arrives late from the GP. This is dependent on what stage of pregnancy the lady attends her GP for referral."
Women attending the maternity unit at Our Lady of Lourdes Hospital in Drogheda, Co Louth, have to wait until the start of the fifth month of pregnancy before seeing an obstetrician due to increased pressure on services, it was reported in The Irish Times last Tuesday.
The Health Service Executive (HSE) confirmed that it could be the 20th week of pregnancy in some cases before a woman secured an ante-natal appointment at the hospital.
Obstetricians prefer women to present for their first appointment at 12 to 14 weeks of pregnancy, a recommendation repeated on the website of the Rotunda hospital in Dublin.
News of the delays comes after The Irish Times reported that a HSE-appointed taskforce had expressed serious concerns about the midwife staffing level at Our Lady of Lourdes Hospital.