Lavinia and Michelle, 49-year-old twins from south London, have discovered they are the first documented case in the UK of heteropaternal superfecundation – meaning they share the same mother but have different fathers. The revelation came four years ago when DNA tests from Ancestry revealed the rare biological phenomenon, which has fewer than 20 recorded cases worldwide.
The sisters, who were born minutes apart, grew up in an unstable childhood, moving between homes and carers. Despite their differences – Lavinia is extroverted and runs a blockchain platform, while Michelle is introverted and owns a sewing company – they share a strong bond. “There’s twin magic,” Michelle says, describing how they can feel each other’s emotions and even physical pain.
Heteropaternal superfecundation occurs when a woman releases multiple eggs during ovulation and has intercourse with more than one partner, resulting in fertilisation by sperm from different men. The twins took the tests after Michelle sought answers about her family history, including why she had little in common with the man they believed was their father.
The case is considered “super weird, super odd, super rare” by experts, as such findings typically emerge only when both twins undergo DNA testing. Lavinia and Michelle now understand their unique origin, which has reshaped their identity as twins and half-sisters.
