The amniotic sac, commonly called the bag of waters, sometimes the membranes, is the sac in which the fetus develops in amniotes. It is a thin but tough transparent pair of membranes that hold a developing embryo (and later fetus) until shortly before birth. The inner of these fetal membranes, the amnion, encloses the amniotic cavity, containing the amniotic fluid and the fetus. The outer membrane, the chorion, contains the amnion and is part of the placenta. On the outer side, the amniotic sac is connected to the yolk sac, the allantois and, via the umbilical cord, to the placenta.
Birth means a new life, and it’s one of the greatest achievement of a woman. While seeing a baby being born is already fascinating, witnessing something like the video below is absolutely mind-boggling. Apparently, the tiny infant was born with the membranes completely intact – an extremely rare occurrence called en-caul.
The marvelous footage shows a baby moving and stretching inside the translucent amniotic sac. En-caul birth occurs when the baby is born inside the entire amniotic sac. The sac balloons out at birth, with the amniotic fluid and child remaining inside the unbroken or partially broken membrane. Being born ‘en-caul’ is extraordinarily rare, occurring in fewer than 1 out of 80,000 births and mostly happens in premature babies.
While the appearance of an en-caul baby might look worrying, the caul is completely harmless and won’t suffocate the infant. The baby breathes through its placenta, which is still attached to its mother. The thin but durable membrane filled with fluid is what helps keep the baby warm and safe from bumps during the entire pregnancy. It can be easily removed by the attending physician or midwife.