Angelina Jolie worries for smaller twin

"[Twins] are never born with identical weights and sometimes one is considerably larger than the other," Nurse Marie Lacroix tells Star. And while both twins doing fine, Angelina just like all mothers of twins "worries for the smaller one."

"She can watch and listen to their two hearts beating side by side," says Marie. "She can watch them both asleep and awake preparing for the big day. She can also monitor the health of the placenta. Where there are two placentas, sometimes the second placenta is much smaller so the second baby doesn't develop quite so robustly as its other."

"Angelina's babies can move and change position and will continue to do so right up until birth," says Marie. "Very often at the time of birth one is head down and one is in breach as that's the way [twins] fit themselves in the uterus as they get bigger. If the first one is head down, we can deliver that normally and then the second in breach position, feet first. You hope not to deliver the second in breach because sometimes the uterus thinks: Okay, I have had my baby now and the cervix closes, trapping the second baby. Then you are left with needing an emergency cesarean for the second one."

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