An Ohio woman has given birth to rare identical “mono mono” twins. In a rare event, the twins shared the same amniotic sac and placenta. According to the Daily Mail, when twins Jenna and Jillian were presented to their parents, they were holding hands. The pair were delivered to mother Sarah Thistlethwaite by Caesarean section at 2.41am. 'They’re already best friends,' Sarah told the Akron Beacon Journal. 'I can’t believe they were holding hands. That’s amazing.' Monoamniotic twins are the rarest type of twins. According to Dr. Melissa Mancuso, who delivered the pair, this normally happens “1 in about 10,000 pregnancies.” Jenna and Jillian were born premature at just 33 weeks and will remain in hospital for the next month. Images via Akron Children's Hospital.