Women with cancer are among those who cannot have their eggs frozen ahead of chemotherapy because of the closure of IVF services.
Last month, hundreds of families were left in limbo after IVF clinics across Ireland were shut down because of Covid-19.
Cancer patients are warned that treatments such as chemotherapy can cause infertility for some patients, and some women may consider freezing their eggs. Most of these women are treated at the Rotunda IVF clinic, a private clinic that gets HSE funding for egg freezing for women with cancer.
A spokeswoman for the Rotunda clinic told the Irish Independent it had stopped all of its fertility services, including those for cancer patients.
"In line with national guidelines and current best practice, we have ceased all non-essential fertility services, including the oncofertility programme.
"We have not received direction from the Department of Health or the HSE that we are to recommence any of these areas at this time.
"We are deeply regretful of the impact this will have on a very vulnerable section of the population but we do have to act in the best interests of our patients and staff," the spokeswoman said.
Assisted reproduction can be time-sensitive for most patients, but especially so for those with cancer.
On its website, the Rotunda IVF states that "the timeline for an oncology patient is often critical and fast".
Cancer patients can often need to arrange fertility treatments quickly, so that their chemotherapy is not delayed.
The eggs have to be removed before treatment starts, and egg freezing can be carried out only at certain stages of a woman's menstrual cycle.
Last month, the Irish Independent reported that women were being urged not to have IVF treatment during the coronavirus outbreak amid fears it could result in giving birth to a premature baby.
It followed advice from the European Society of Human Reproduction and Embryology (ESHRE).
The ESHRE said that while research on the impact of Covid-19 on pregnancy was limited, women should take a precautionary approach.
In an updated statement on April 2, the ESHRE said that "urgent" fertility treatments for cancer patients should still be considered.
The Irish Cancer Society said that the decision to close IVF services would be "particularly upsetting to people about to undergo treatment for cancer who may wish to have children later".
It has contacted the HSE and the Department of Health to ask whether "fertility preservation for cancer patients can be considered as an 'urgent' procedure and therefore go ahead during the coronavirus crisis".
"Fertility is a concern for any woman who is undergoing cancer treatment and all options should remain available to those women.
"Pausing this treatment could mean that a cancer patient could have a much reduced chance or no chance at all of having a child after treatment," a spokeswoman said.
Each year, there are 6,000 IVF cycles undertaken in Ireland.
Earlier this week Dr John Kennedy, the group medical director of Sims IVF, said that some European IVF clinics claimed they would be open again in June but he did not know "how they can make that statement".
Emergency restrictions will not be eased until our coronavirus testing regime is improved to the point where it is possible to "hunt down" positive cases and contacts within 24 to 48 hours, chief medical officer Dr Tony Holohan warned.
Business groups and parents of secondary school children have called on the Government to set out how it plans to ease the extraordinary restrictions imposed due to the coronavirus crisis.