Belfast Trust has confirmed that it has treated 12 pregnant patients who have tested positive for Covid-19 in the past week.
The Trust, which operates seven hospitals, has said that babies with the virus must be isolated for 10 days after they are born. Something which is affecting capacity issues at the hospitals.
Pregnancy results in reduced lung capacity, something which is further exasperated with increased pressure on the lungs caused by Covid-19.
In a statement, Belfast Trust said: "We have recently had to arrange preterm delivery for a number of women. In these instances, their babies required admission to the neonatal intensive care unit."
There are currently six babies in isolation in the hospitals concerned.
In cases where a baby is in the neonatal unit and the parents have tested positive for the coronavirus, parents will not be permitted to hold their baby until they have completed the required period of isolation or had a negative PCR test. This is for infection prevention and control reasons.
New data has found that unvaccinated pregnant people are more at risk. A recent study by the UK Obstetric Surveillance System (UKOSS) suggests that while they are no more likely to catch Covid-19, they are recognised to be at a slightly increased risk of becoming severely unwell.
Should a pregnant patient become ill with the virus, they are more likely to require admission to hospital and require additional breathing support.
The Belfast Trust has said pregnant patients are having to be ventilated with the majority being hospitalised in their third trimester, over 26 weeks.
Anyone who is pregnant and has concerns about getting the Covid-19 vaccination should speak to their midwife, GP or hospital consultant for the most up-to-date scientific advice.