Two medical experts testifying at the trial of Andrea Giesbrecht, the woman accused of concealing the remains of six infants in a Winnipeg U-Haul storage locker, say it was likely that some, if not all of the babies, were born alive.

Dr. Michael Narvey and Dr. Sharon Naughler​ both told the court on Thursday that it would be very unlikely for a woman to have six stillborn births.

Narvey, a neonatologist who had been provided with autopsy results by Winnipeg police, called the possibility of six stillborn births "very, very improbable."

He also testified that the remains found in Giesbrecht's rented storage locker in October 2014 would have been between 34 and 42 weeks gestation. Full term is considered to be 37 weeks, he said.

"I believe some if not all of these children would have been born alive," Narvey told the court.

Andrea Giesbrecht is shown in this surveillance camera image from the McPhillips Street U-Haul facility in Winnipeg on Oct. 3, 2014. The video footage was presented at Giesbrecht's trial, which began Monday. (Court exhibit)

Naughler, an obstetrics and gynecology expert who is currently head of obstetrics at the Women's Hospital in Winnipeg, said Thursday afternoon that everything appeared normal in medical records from Giesbrecht's 2002 pregnancy.

Giesbrecht has two sons, with the older boy born in 1997. She received medical attention while pregnant with her second son in 2002, court heard.

Naughler said based on Giesbrecht's medical history, the chance of having six stillborn births is one in 500 trillion, which she said is "medically impossible."

The Crown asked Naughler how likely it was that the infants whose remains were found in the storage locker would have been born alive.

"Highly likely," Naughler told the court.

Remains badly decomposed

Both medical experts testified that they cannot say with absolute certainty that the infants were born alive because the remains were badly decomposed when they were discovered.

Naughler said pathologists who conducted autopsies on the remains could not detect oxygen in the lungs, given the condition of the remains, and therefore they could not determine if the infants were stillborn or not.

Winnipeg police outside the U-Haul storage locker facility on McPhillips Street where the infant remains were discovered in October 2014. (CBC) Narvey said if one looks at the probability, based on medical literature, that all the infants were stillborn, he said it would be improbable but not impossible.

Giesbrecht, 42, faces six counts of concealing bodies. The judge-only trial began Monday in provincial court in Winnipeg and will continue tomorrow, then resume in August.

Court has heard that the infant remains were discovered on Oct. 20, 2014, inside a storage unit rented by Giesbrecht under her maiden name, Naworynski. They were in various states of decomposition, wrapped in kitchen-style garbage bags, placed in duffel bags and stored in large household containers and pails.

Experts determined the remains belonged to five boys and one girl, court heard earlier in the trial.

"No evidence of any anomalies in these babies," Naughler told the court, adding, "I can't think of any congenital anomaly that could explain six stillbirths."

The trial has to yet to hear any testimony about why the infants' remains were kept in the storage locker.

Greg Brodsky, Giesbrecht's lawyer, is expected to present evidence in her defence later in the trial. He has said the case will hinge partly on whether the infants were born alive, and the legal issues at play in relation to stillbirths and miscarriages.

Pregnant 18 times

On Wednesday, a forensic biologist testified the remains have been linked to DNA found on a soiled sanitary napkin that was in Giesbrecht's home. The biological father of the infants was Jeremy Giesbrecht, Andrea Giesbrecht's husband, court was told.

In cross-examining Naughler, Brodsky said Giesbrecht was pregnant a total of 18 times between the ages of 20 and 38. He asked the doctor if that's normal.

Naughler​ said yes, provided that a woman is fertile and does not use birth control.

Court heard that in addition to her two sons, Giesbrecht had nine abortions and one miscarriage between 1994 and 2011. The number of pregnancy terminations was confirmed by Giesbrecht's lawyer.

Both Narvey and Naughler were asked about various potential causes of stillborn births, including uterine infections, complications related to the placenta, hypertension and diabetes.

In those cases, the experts said the mother would be harmed or even die as a result of those complications.

When asked about abortions, Narvey said the procedures are generally allowed to be performed until 24 weeks gestation.

Narvey was also asked about what conditions could cause spontaneous abortions, also known as miscarriages. He said deaths under those circumstances would happen in the first or second trimesters only.

"The baby is at the mercy of the placenta and the mother, so to speak," Narvey told the court.

When asked by prosecutors if a mother could "self-abort" and cause deaths in utero, Narvey said it's possible to do so by inserting something into the cervix. However, that would only cause death early in the pregnancy, before the fetus's lungs are formed, he said.

If the mother ruptured her amniotic sac late in pregnancy, it would induce labour and the baby would be born alive, Narvey said.

Follow the recap of our live blog written by Caroline Barghout, who is covering the trial this week. Warning: Some details may be graphic.