Rare 'mono mono' identical twin girls are born HOLDING HANDS (photos)

An Ohio woman gave birth to identical twin girls on Friday - who in an extremely rare event happened to have shared the same amniotic sac and placenta. 

Jenna and Jillian were delivered by Caesarean section at 2:41pm at Akron General Medical Center, the Akron Beacon Journal reports, and were holding hands when presented to parents Sarah and Bill Thistlethwaite in the delivery room. 

'They’re already best friends,' Sarah told the paper. 'I can’t believe they were holding hands. That’s amazing.'

Dr. Melissa Mancuso, who delivered the monoamniotic girls along with Dr. Katherine Wolfe, told the paper that something like this normally 'happens in about 1 in 10,000 pregnancies and 1 to 5 percent of all twins.'

Monoamniotic twins are the rarest type, Mancuso told the paper, with risks including birth defects and tangled umbilical cords that might kill a twin.  

Jenna and Jillian, born premature at 33 weeks and 2 days, will probably spend two to four weeks in the nursery, the paper says.

Mother Sarah Thistlethwaite, a middle school math teacher, delivered the twins after spending 57 days in bed, according to the Beacon Journal. Once told she would be unlikely to have children, her 15-month-old son Jaxon was looked after by family and friends while she waited to give birth. 

A hospital press release noted that Sarah, who took leave from her teaching position, was visited by husband Bill visited her every day after work.

In a twist, the paper reports that Amanda Arnold, another patient at Akron General, is set to give birth to mono mono twins this week.