Visiting the obstetrician or midwife is the only medical appointment that many people actually enjoy. Each appointment is an opportunity to appreciate that the small, day to day changes have actually wrought great progress over the course of a month. It may seem that the obstetrical appointment is little more than a social engagement, with lots of conversation and very little obstetrical practice. However, with a few simple measurements, a lot of information can be gleaned about your developing baby's health.
Your practitioner starts each visit with questions about the baby's progress, and your pediatrician will do the same in the future. Have you felt the baby move yet? Most women expecting their first baby will notice fetal movement sometime after the 16th week, possibly not until the 20th week. Many women who have already delivered a child may perceive fetal movement even earlier.
The baby is also measured indirectly by measuring the fundal height, as mentioned in Chapter 2. The measurement of fundal height, in centimeters, normally corresponds to the age of the pregnancy, measured in weeks from the last menstrual period. So if you're twenty weeks pregnant, your fundal height should be approximately 20 centimeters (cm.).
Finally, the baby is evaluated by placing a doptone (see the first illustration in this chapter) on the mother's abdomen to listen for the baby's heartbeat. The doptone uses sound waves to sense the movement of the fetal heart and produces an audible beating sound that mimics the heart rate. The fetal heart rate should be between 120-160 beats per minute, although it may go higher for brief periods when the baby moves.
As you might imagine, though, the best way to assess the baby's health is to see the baby, and this can be done even before the baby is born, using ultrasound technology. Not only can the baby be measured and its weight calculated from those measurements, its internal anatomy also can be evaluated.