One support group said it has received a barrage of calls in recent days from anxious patients at Glasgow Royal Infirmary unclear if their failed attempt at assisted conception is linked to the hospital.
Building work at Glasgow Royal Infirmary (GRI) is one potential cause of pregnancy rates falling from around one-third to 15% at the Assisted Conception Unit in the hospital.
However, Gwenda Burns, the Scottish branch co-ordinator for Infertility Network in Scotland, said patients had learned of the high rate of failed conceptions through news reports.
She said: "What we are extremely disappointed about is that we didn't know about these issues until the story broke in the media.
"Patients who have gone through their treatment when this has possibly happened hadn't been notified.
"There is not a lot of information coming from GRI, which is causing even more emotional upset. They have to wait on a letter being sent, which isn't helping."
With clinical error ruled out, it is thought the building work may have led to contamination in the laboratories where embryos are prepared for implant.
Women and their partners in the midst of treatment, or who are setting out on the IVF path, have now been moved to a private clinic while the investigation goes on.
A free round of IVF has been offered to those who had an unsuccessful treatment at GRI between September 1 and November 9.
A spokesman for Greater Glasgow and Clyde NHS said last night: "We have already been in direct contact with patients who are currently receiving treatment. In addition, the 37 patients who exhibited reduced or no fertilisation during the period when our pregnancy rates were reduced have all been sent a letter today and offered a complimentary cycle of treatment.
"Clearly, many patients who have read the media coverage are concerned that their treatment may have been affected.
"We would like to make it clear that the period of concern is for treatment occurring over a defined period only, from September 1 to November 9. Outwith this time period there is absolutely no cause for concern."
The GRI conception unit caters for women from NHS Greater Glasgow and Clyde, NHS Lanarkshire and NHS Dumfries and Galloway, all of whom receive two free IVF treatments, plus NHS Ayrshire and Arran, who receive three. As a result of the issues at GRI, around 25 NHS patients a week are now receiving IVF at the city's private Nuffield hospital.
Ms Burns said: "IVF and fertility treatment is not easy. It's very invasive and it's not as easy as saying you'll get a free cycle. Potentially, you are going to have to go through it again when they have already been dealing with having a failed cycle."
Professor Richard Fleming, a specialist in reproductive medicine and director of the Glasgow Centre for Reproductive Medicine, earlier told The Herald similar cases in the past would suggest air vents contaminated with toxic fumes and particles from building works may be to blame.