Glucose Monitoring During Pregnancy

The best method for tracking and controlling blood sugars is to use a lancet to obtain a blood sample and a glucometer to measure the sugar level.

Pregestational Diabetes [Type 1 and Type 2]:

If diabetes was present before pregnancy, it may be necessary to check up to seven blood sugar levels per day until sugars are well controlled. For example, fasting/pre-meals, 1-hour post-meals and 2-3 AM blood sugars. Once good control has been reached, the number of blood sugar check may be decreased to 4 times per day (usually pre-meal blood sugars). If pre-meal blood sugars are over 100 mg/dl, an insulin sliding scale is used to determine the dose of fast-acting insulin.

Gestational Diabetes

If gestational diabetes develops, it is seldom necessary to monitor blood sugars more than 4 times per day. The best times to monitor are fasting in the morning and 1 hour after breakfast, lunch and dinner.

Monitoring should be performed daily for the first week of adoption of the diet. If blood sugars are normal (60-90 mg/dl fasting and < 120 mg/dl 1 hour after meals), monitoring can be reduced to two days per week. Those taking insulin to control blood sugars should continue testing every day, four times per day.

An accurate record of all measured blood sugars should be entered in a logbook and brought to every doctor's visit. In addition, efforts should be made to record dietary intake including meals and snacks. This allows health care providers to carefully review dietary intake and make recommendations for improvements in blood sugar control if needed.

There are many glucometers (blood sugar meters) available at pharmacies. The physician or diabetes educator should be consulted for advice regarding which meter is right for you. Most insurance carriers cover the cost of the meter but they do not always cover the cost of the test strips that are needed for the glucometer to function.

For women with gestational diabetes, most high risk OB practices or "Diabetes in Pregnancy Programs" have "loaner programs" where glucometers can be borrowed for the term of the pregnancy. Over the past few years, there have been significant improvements in lancing devices and lancets that minimize the discomfort of finger sticks Several meters are now available which are approved for use with blood obtained from alternate sites such as the forearm, fleshy part of the hand, upper arm or calf. In addition, several meters can now measure the sugar level with a very small sample of blood.

Avoiding Common Errors

Despite technological developments that have definitely improved the process of blood glucose monitoring, false results can occur if the strips are outdated, the meter is soiled or in extreme temperature conditions.

Defective or Outdated Strips

Strips should be stored in the vial or foil wrapping they come in, according to the manufacturer's guidelines. Leaving them exposed can lead to false results. All strips should have an expiration date and if the strips were shipped in an unheated delivery truck, they could be defective.

Control solution should be used on the first strip in each box to verify that the strips are accurate. Every strip is compatible with its own control solution and use the control solution as if it were a drop of blood. The acceptable range of results is printed on the vial or package of strips. If the results are out of this range, call the manufacturer's toll-free customer service number for replacements.

Soiled Meter

Some meters need to be cleaned in order to obtain accurate results dependent upon how they measure blood sugars. Meters measure blood glucose in one of two ways: using color reflectance or sensor technology. With reflectance meters, the blood sugar in a drop of blood reacts with an enzyme on the strip and changes the color of the strip. The meter reads the darkness of the strip and gives a number readout of the sugar value. If the window is dirty on these meters, a false high reading can occur. Almost all the newer meters use sensor technology to measures small electrical currents produced by the chemical interaction between the glucose in the blood and the chemicals on the strip. These usually do not require cleaning.

Heat or Cold

Temperature extremes (heat and cold) can affect the accuracy of blood sugar readings. Many meters have temperature warning indicators that alert the user when the air temperature is above or below the operating range of the strips. The One Touch Ultra has the widest temperature range from 43 -110 degrees Fahrenheit.

Check the owner's manual for a specific unit.