The Master of the Rotunda Hospital in Dublin has told an inquiry that a doctor under review was right to diagnose an ectopic pregnancy and that conservative management of the case would have put the mother's life at risk.

It is alleged at the ongoing Medical Council inquiry that in January 2013 a consultant obstetric and gynaecologist, identified as Dr A, mistook Laura Esmonde's ovary for an ectopic pregnancy at Tipperary General Hospital.

The hearing previously heard that Dr A advised the mother-of-three that the safest course of action was for her to take two courses of methotrexate, a medication used to stop ectopic pregnancies from growing.

On the evening of 8 January, Ms Esmonde took her first dose of methotrexate and took a second dose on 17 January. No further ultrasound was conducted before this second dose, she said.

On 26 January, she was transferred to Cork University Hospital for treatment of a leg clot, where a scan indicated her pregnancy was not ectopic.

A further scan showed a normal intrauterine pregnancy but it was no longer viable. Ms Esmonde miscarried on 2 February.

Professor Fergal Malone, Master of the Rotunda, who was called as an expert witness of behalf of the doctor, said that based on the information available to Dr A on the afternoon of 8 January, an ectopic pregnancy was the most likely diagnosis.

He said that it was reasonable to exclude a viable pregnancy on 8 January, given all the clinical factors.

He later added that the pregnancy was most likely an ectopic one, but that it was also possible that it was a non-viable intrauterine pregnancy.

Prof Malone said it was "highly, highly unlikely" that the pregnancy was a viable intrauterine one.

He discussed the options available for managing a possible ectopic pregnancy. One was surgical, which he said was not a "wise choice" because Ms Esmonde was taking blood thinners to treat the major blood clot in her left leg, and would carry a significant risk to her.

Another was called conservative management, that is, a "wait and see" approach.

Prof Malone said this was also not an option in the case of Ms Esmonde because if her fallopian tube had later ruptured, she could have suffered serious blood loss due to the blood thinners she was taking, and possible death.

"Watchful waiting would not have been wise because if you got it wrong, there would have been a high probability of death," said Prof Malone. "Waiting in this particular clinical situation was fraught with danger."

He said the only option left was medical management, that is, the prescription of methotrexate, which was designed to end the pregnancy.

"This is a dreadful scenario," said Prof Malone, "but the methotrexate seemed the lesser of the two evils. Active intervention with medical management was the best option in terms of protecting the mother."

He added that the situation must have been "terrifying" for the patient.

"We would never wish anything but the best for any life, including the tiniest embryo…but our overall, number one goal is a healthy mother."

Prof Malone described the situation that Dr A found himself in as one of the most "challenging" situations an obstetrician and gynaecologist could find themselves in.

"Overall, I was struck by the sheer complexity of this case," said Prof Malone, whose hospital is one of the busiest providers of the management of ectopic pregnancies in Europe.

"This was amongst one of the most challenging early pregnancy clinical scenarios an obstetrician could find himself or herself in."

Prof Malone said one must look at the clinical context of this case. "This was a uniquely complex situation," he said, "and medicine is an imperfect world."

Prof Malone's evidence contrasted with that given by the expert witness on behalf of the Medical Council.

On Monday, Dr Philip Owen said Dr A likely mistook Ms Esmonde's ovary for an ectopic pregnancy before giving her the methotrexate.

Dr Owen, a consultant obstetrician and gynaecologist in Glasgow, said it was more than likely Ms Esmonde had a continuing normal pregnancy in her womb when she was given the methotrexate.

"My interpretation is he was looking at small fluid area within the right ovary and mistook it for an ectopic pregnancy," Dr Owen said on Monday. The inquiry continues tomorrow.