DC 2007-04-20, In The Womb 子宫日记 9

As the fetus explores her body, she spends a lot of time practicing her grasping reflex, grabbing hold of her hands, feet, fingers, toes and even her umbilical cord. Twins seem to have more fun, grasping and seemingly wrestling with each other. Identical twins show early contact at 12 weeks, and by 14 weeks are touching arms, legs, bodies and mouths. This close physical contact seems to occur earlier between female twins.

Nonidentical or fraternal twins are separated by membranes in the womb and don't have the same opportunity to bond with their sibling. The membrane in this 4-D scan can be seen just above the elbow of the lower twin across the middle of the picture. As identical twins grow bigger, they are almost always in contact, touching hands, faces, feet, and gradually becoming more aware of themselves and each other. This constant contact in the womb is mirrored in early life and is partly responsible for the incredibly close bonds the twins feel throughout their lives.

At 18 weeks, the fetus begins to mimic life outside the womb. Her digestive system shows signs of activity. She has no need to eat or drink, but as can be seen in this 4-D image, she begins to swallow the fluid she is floating in, the amniotic fluid. Some indigestible waste gathers in her intestines in the form of a greenish black paste called meconium. But most of the fluid passes through her urinary system and back out to rejoin the amniotic fluid.

Around this time when the fetus is about 18 weeks old, the mother may become aware of its movements for the first time. Although the fetus has been active for quite some time, it's only now that her movements are strong enough for her mother to feel. Women who have been pregnant before tend to be more alert to this slight fluttering sensation and may feel it when the baby is just 15 weeks old.

The eyes now in their correct position are generally thought to remain fuse shut until 24 weeks, but 4-D ultrasound has revealed some fetuses opening their eyes as early as 18 weeks. It's dark of course, so there is nothing to see. But even if there were light, the eyes don't work this early. It's just the first sign of the blinking reflex. The fetus, which has been growing for nearly 5 months, is half way through her journey toward birth.

words and phrases:

grasping reflex: 抓握反射
grab hold of ： 抓紧