Being pregnant for the first time is a mixture of excitement and anxiety. Sure, there are frequent pre-natal visits, but some mothers would like to monitor their babies on their own. As early as 20 weeks, mothers can use at-home heart rate monitors (like the BabyBeat Fetal Doppler) to listen to their baby's heart and ensure that there is adequate oxygen flow and no troubles in the womb. Purchasing a baby monitor system like this was until recently very expensive ($499!), however prices have now dropped  so expectant mothers can pick one up for under $100.

A baby heart rate monitor is available in external and internal types. Using an external baby monitor system during pregnancy will report the baby's heart rate, measure the duration of contractions, tests for infant stress and evaluate amniotic fluid levels. This type of baby infant monitor may be a stethoscope, two flat elastic sensors or an ultrasound machine. Sometimes the information is heard as a beeping sound, while other times, a chart reading is printed out. Heart monitor readings are a great way to ensure the health of the baby and sense uterine contractions during labor.

Baby heart rate monitors can also be internal. Usually the internal baby monitor system is only used when complications arise during labor. Once the mother's cervix has dilated at least two centimeters and the amniotic sac has ruptured, continuous internal monitoring is done to find out whether the stressfulness of labor is threatening the baby's health and also to measure the strength/duration of labor contractions. To do this, an electrode is inserted in through the vagina, cervix, uterus and to the baby's head. Chart print-outs and beeping sounds let doctors and nurses know exactly what's going on during this urgent time.

Most external heart rate monitors are used after 20 weeks of pregnancy. The woman being tested will lie on her back or left side, with two sensor belts attached around her belly. One sensor will track the baby's heart rate, while the other measures the timing and strength of her contractions. The sensors attach to a recording device, which beeps or prints out reports immediately. During a 30-minute non-stress test, the mother will be asked to push a button whenever the baby moves or whenever she has a contraction. During the contraction stress test, contractions are induced using oxytocin intravenously, while contractions are measured. All in all, digital baby monitors are the best way to ensure the health of a forthcoming baby.