Tuesday, August 12, 2014

What Every Pregnant Woman Should Know about Glucose Screening (OGTT)

One of the tests that all pregnant women have to go through is the glucose screening test.  The first glucose screening test, known as OGCT or Oral Glucose Challenge Test is normally recommended by the OB Gynecologist between 16 to 20 weeks of gestation. 

The OGCT is given to measure the body's ability to utilize glucose as the body's main source of energy. It is administered by giving the pregnant patient 50 grams of glucose drink that has to be consumed within 5 minutes. After which, blood is extracted intravenously regardless of the time of the patient's last meal. Thus, no fasting is required for this test. 

If glucose levels are equal or above 130 mg/dl, your OB GYN will most likely refer you to a more rigorous and definitive glucose testing called the OGTT or Oral Glucose Tolerance Test.  

I dreaded taking both glucose screenings because I developed gestational diabetes (GD) during my first pregnancy. My OB GYN, Dr. Elsie Pascua then referred me to an endocrinologist, Dr. Michael Villa who specializes in diseases of the endocrine and hormones.  She also referred me to a nutritionist who gave me a special dietary plan to help regulate my glucose levels after each food/ meal intake. Even though I do not really have a sweet tooth, I learned that our family history of Type 2 diabetes has put me at risk in developing GD.

From my 6th month of pregnancy until delivery and recovery, I was closely monitored by Dr. Villa. He gave me a glucose screening kit so I can monitor and log my glucose levels upon waking up and after every meal.  With proper diet and exercise, I was able to manage my glucose levels and did not have to take insulin shots. After I had given birth, I also had to go through an OGCT again to check if I had developed Type 2 diabetes. It was a blessing that I didn't, but given the history, it still puts me at risk of developing the disease. It also puts me at risk in having gestational diabetes again on my succeeding pregnancies. 

Although there are no known causes for gestational diabetes, some medical experts say that hormones from the placenta may block the action of insulin in a pregnant woman's body. This insulin resistance will cause glucose to build up in the blood instead of it being used as energy for the body. 

If untreated properly, GD can be harmful for your baby. This excess glucose can go through the placenta and give your baby high glucose levels. The baby's pancreas will work overtime to produce insulin and get rid of the excess glucose in his blood which may result to a fat baby. This puts your baby at risk for obesity and may also develop Type 2 diabetes later on.

(Source: www.diabetes.org)

I took the OGCT on my 20th week of pregnancy. The result was 175 mg/dl, which was obviously way over the acceptable blood glucose limit. My OB then recommended that I take the second glucose screening, OGTT on my 24th week. 

Because I had GD on my previous pregnancy, I was anxious about getting the results. I also dreaded the whole process of the glucose screening itself. The OGTT is a long and tedious screening and requires half day of fasting -- not a welcome idea for any pregnant woman. I was not prepared the last time I took this test, but I knew better this time. So if you're going to take this test, whether pregnant or not, here are some important things you should know about OGTT:

1.  OGTT requires 8 to 12 hours of fasting.  We had guests over in the house the night before I scheduled the test, but I made sure my last food and water/ fluid intake would be at 11 pm. I got to St. Luke's Global Pathology Dept. at 8 am the following day. Scheduling the test first thing in the morning is the best thing to do so you can avoid the long queuing in the laboratory and won't end up very hungry and heaven forbid, irritable! I was given a log slip that I just had to present when it was time for my next extraction.

2.  The standard test requires 4 blood extractions for 3 hours (unless the doctor specifies a 2 or 4 hour OGTT). The extractions are done every hour and no food or water is allowed in between extractions.

3.  The first blood extraction is for your fasting blood. After which, you are given a 100 mg. glucose drink that has to be consumed within 5 minutes. The drink is extremely sweet and can make you gag. It is important to prevent yourself from throwing up because this will make the test invalid.


4.  After taking the glucose drink, your blood will be extracted 3 more times every hour. During this time, no food or drink, including water is still allowed. I was also advised to refrain from too much walking. To pass the time, I waited in the different lobby areas of St. Luke's Global and the read the books I brought along. As I said, the process is long and tedious so you have to be patient.


Before the last blood extraction, I was already feeling a bit dizzy and super hungry.  It was almost lunch time so before heading home, I got myself something to eat in the car.  After more than 3 hours of passing time in the hospital, it felt so good to see my log slip all signed and completed!

After a couple of days, I downloaded the result of my OGTT online through St. Luke's eHealth Patient's Results - a very convenient advantage of having your results done in St. Luke's. 

And the result.....

I PASSED!!! I was so overjoyed! However, my OB advised me to take it easy on carbs (especially simple sugar) on my last trimester. While I can give in to my occasional banana walnut muffin craving, I could only thank God that I have one health issue to be concerned about in my pregnancy.   


  1. Hi Tins! I had GD also when I was pregnant with Ikay. I also don't like these tests. Sana next pregnancy ko no GD na din :-) praise God for your results!
    - Yhan

    1. It's hard right? Did you have to take insulin shots?