Pregnancy

The Woman During Pregnancy: Possible Problems and Complications:
Prenatal Tests

Ultrasound Scan
Using sound waves of very high frequency, an ultrasound scanner produces a “live” picture of the fetus on a screen. The sound waves are aimed at the uterus where they “bounce off” the body of the fetus, creating a moving electronic image. For this, a transducer is placed on the woman’s abdomen, where it can be slightly moved around to make the fetus visible from different angles. (Very early in the pregnancy, a transducer is placed in the vagina.) The ultrasound scan is a simple and painless procedure. Usually, the mother can also obtain a print-out of the screen image and thus receive her first “baby picture” (a sonogram). Recently, scanners have been developed that provide three-dimensional pictures, but this 3D technology is not yet widely available.
An ultrasound scan can asses the growth of the fetus, a possible multiple pregnancy, the location of the placenta and the amount of amniotic fluid. It can also detect an ectopic pregnancy and several other problems. For example, it can find certain indications of possible birth defects. However, it cannot detect all abnormalities themselves. If a real risk of such defects is found, further tests and genetic counseling become necessary.
Ultrasound scanning also allows to detect the sex of the fetus, usually after the 15th week of pregnancy, but sometimes even sooner. This possibility has been abused in some countries where people favor the birth of sons over that of daughters. Thus, female fetuses were aborted until a new pregnancy produced the desired male fetus as proven by ultrasound. In the meantime, this has led to an imbalance of the sexes in some areas, i.e. a worrisome preponderance of boys who, as adults, may have trouble finding wives close enough to home.