During your pregnancy, your baby will grow from a microscopic fertilized egg to an average of about 8 lb at birth. Fetal development follows predictable stages and milestones, with some individual variance. Throughout your pregnancy, your health care provider will monitor your unborn child to make sure she is healthy and growing properly. If your fetus does not achieve expected milestones at the expected times, there could be a problem with the pregnancy, or the gestational age of the baby may have been miscalculated.
An ultrasound allows your health care provider to measure your baby and look for signs of normal growth and development. Serial ultrasounds are the most commonly used tool to assess fetal development in all pregnancies and especially in multiple pregnancies. Ultrasounds can help diagnose a baby with intrauterine growth restriction or umbilical cord anomalies, potentially serious conditions, or normal growth patterns that just indicate a smaller baby. Early pregnancy ultrasounds can be used to calculate the gestational age of the baby.
As your baby grows, your uterus will expand. Your health care provider will measure from the top of your public bone to the top of your uterus; this measurement is known as fundal height. If your baby is growing normally and you are gaining weight at an appropriate rate, your fundal height will regularly increase in expected amounts as your pregnancy advances. If your fundal height does not correspond with your baby's gestational age, being either too large or too small, your health care provider will typically order an ultrasound as an additional diagnostic tool.
HCG Blood Levels
When you are pregnant, your body begins to produce HCG, or human chorionic gonadotropin. Urine and blood tests for pregnancy look for the presence of this hormone. In early pregnancy, your blood levels will increase in regular amounts and at regular intervals. If pregnancy problems are a concern, your doctor may take serial HCG blood levels. If your HCG levels do not rise as they should, or especially if they are decreasing, your fetus is typically not growing properly and a miscarriage may be inevitable.