Health experts say all three of those mechanisms have to go wrong for superfetation to occur, usually due to fertility treatments.
Superfetation comes with risks since the fetuses are growing at different stages of the pregnancy.
Insider.com reported Roberts as having said that her fertility medications influenced her ovulation, allowing her to ovulate again three weeks after her first conception.
Doctors had told her that her younger child, Rosalie might not survive but that prediction failed, fortunately.
“What came after getting pregnant was just such incredible hard work,” Roberts told GMA. “It wasn’t all happy and rainbows like you expect pregnancy to be. It was quite scary.”
She gave birth at 33 weeks prematurely because of a problem with Rosalie’s umbilical cord that prevented her from growing properly, according to reports.
#Pregnant #woman #pregnant #weeks #birth #twins #day