A consultant gynaecologist and fertility specialist told the court that couples who undergo IVF treatment should be allowed to donate embryos to others.
However, fertility clinics here don't offer this option, said Dr Mary Wingfield, a director of the Merrion Fertility Clinic in Dublin.
Donation "should be legislated for", as it was a valid option, she said. She agreed it is "a very complex issue".
Other countries have regulations which allow children born as a result of an embryo adoption to find out who their biological parents are, once that individual turns 18 years of age, she added.
Under cross-examination by Gerard Hogan SC, for the woman in the case, Dr Wingfield said there is a lot of disagreement within the scientific community about when exactly life begins.
She believed pre-implantation embryos were significant potential human beings which deserve respect and legal protection, but did not regard them as entities worthy of the same protection as a human being. Her belief was that life begins when the embryo was 14 days old - the "primitive streak" period.
Society's understanding about when exactly life begins has changed throughout the ages, said Dr Wingfield.
In the 18th century, many churches, including the Catholic Church, believed that life only began when the unborn child first kicked its mother.
She agreed with Mr Hogan that future scientific advances could possibly make her change her opinion. However, while there was a lot of exciting new research going on to determine when exactly life begins, it had not been "validated" and such studies would take "years" before they were completed.