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Next Chapter: Screening for Fetal Abnormalities
At every obstetrical visit, three aspects of your health are always measured. You are weighed, your blood pressure is checked, and your urine is tested for the amount of sugar and protein it contains. Why are these measurements so important?
Maternal weight provides both general and specific information. Good weight gain is usually associated with good fetal growth. You may find it hard to accept the idea that gaining weight is not only anticipated, it is also appreciated. You should not worry about a weight gain of 30 pounds or more. Remember, pregnancy is no time for dieting. However, in general, maternal weight gain should not exceed 40 pounds.
Checking your weight gain is helpful for monitoring excess fluid retention, which is a possible warning sign of pre-eclampsia. Pre-eclampsia (also known as toxemia or pregnancy-induced hypertension) is a disease of pregnancy. It is most common among women who are pregnant for the first time, and no one understands what causes it. Pre-eclampsia is characterized by high blood pressure, edema (swelling due to excess fluid retention) and protein in the urine. It can also be associated with other, even more serious problems. Fortunately, it can be effectively treated in the short term with medications, and reliably cured by delivering the baby.
The incidence of these symptoms explains the importance of the blood-pressure check and the urine assays (an assay is a test). Elevated blood pressure and the presence of protein in the urine are both early signs of pre-eclampsia. If these signs are present, your doctor or midwife can advise specific measures to lower your blood pressure and monitor you for signs of advancing illness. In most cases, bed rest can help control blood pressure elevation. Some cases of pre-eclampsia may require inducing labor before it begins spontaneously, often with no need for medication. Serious cases may require specialized medication and other intervention.
The medical assistant also evaluates your urine for the presence of glucose (sugar) in order to diagnose another pregnancy-related condition, gestational diabetes. Like other forms of diabetes, gestational diabetes affects the body's ability to process sugar. This form of diabetes results from the effect of pregnancy hormones on glucose metabolism, but it is completely reversed after delivery. Modification of the mother's diet can usually manage most cases of gestational diabetes. Insulin is rarely required. However, measuring the glucose in the mother's urine is a very imprecise diagnostic tool. Measuring the concentration of glucose in the mother's blood after she has drunk a sugary drink is a far better test. This is known as the glucose tolerance test, or the one-hour glucola. If you are given this test, you are asked to drink a very sweet orange drink, and one hour later a sample of your blood is drawn. If the blood sugar content is above a certain level, you might be at risk for gestational diabetes, and further tests are indicated.