Delivering Women of Risk of Gestational Diabetes
At 5:16 p.m. last Sept. 16, Megan Sinclair (not her real name) gave birth to an 11-pound, 23-inch-long boy at Huntington Memorial Hospital in Pasadena.
“I had to blink and look twice,” Sinclair, a petite woman who gained 40 pounds during pregnancy, said. “I thought he’d be big, but not that big.”
Her normally reserved husband couldn’t restrain his pride and joked with the hospital staff that he had fathered the next middle linebacker for the Los Angeles Rams.
One doctor dubbed the whopping infant “superbaby,” and the name seemed to stick.
Then one nurse, astonished by the baby’s size, spoiled all the fun.
“I overheard her say, ‘Oh, the mother must have had diabetes,’ ” Megan Sinclair recalled. “I started to worry and asked my obstetrician if it was true. He said he wouldn’t know until I became pregnant again.”
With one offhand remark, Sinclair’s bundle of joy gave rise to a flood of questions. Did she really have diabetes, and if so, where did it come from? Was the baby in any danger? Was she?
Goes Away After Birth
According to Dr. Dorothy Hollingsworth, professor of obstetrics and gynecology at the University of California at San Diego, the mother had cause for concern, but not alarm. She said Sinclair may have suffered from gestational diabetes, a type of high blood sugar that occurs only during pregnancy and usually goes away after the baby’s birth. It affects 2% to 3% of all pregnancies or between 60,000 to 90,000 women a year.
Uncontrolled, gestational diabetes involves serious risks for the mother and unborn child. It can increase the infant’s size dramatically, traumatizing the mother’s delivery, and upset the neonatal metabolism, causing illness or even death in the newborn. For the mother, the disease also may be a sign that she will develop diabetes later in life.
Sinclair’s delivery was traumatic. She had strong contractions three minutes apart for 16 hours, which led her to abandon plans for a drug-free natural, Lamaze delivery. The long labor going nowhere, Sinclair finally delivered a blubbery, but blissful baby by Caesarean section.
Her doctors didn’t know whether she had gestational diabetes because she was never tested for it. That test was recommended for pregnant women most recently by the second International Workshop-Conference on Gestational Diabetes last fall in Chicago.
Hollingsworth, who attended, said: “Every pregnant woman is given a test for syphilis, but since I’ve been at UC San Diego, I haven’t seen a single case. But I have seen hundreds of women with gestational diabetes.”
Dr. Lois Jovanovic, an assistant professor of medicine, obstetrics and gynecology at New York Hospital-Cornell Medical Center, responsible for teaching diabetic women how to cope with the disease, echoed her colleague’s remarks: “The doctors I know would be embarrassed not to give every pregnant woman the test.”
The test, which costs about $5, consists of drinking 50 grams of glucose and having blood drawn one hour later. If a woman tests positive, usually higher than 150 milligrams per deciliter after an hour, a three-hour oral glucose tolerance test is performed.
If that second, more extensive test proves positive as well, the doctor advises the patient about diet, exercise and the possibility of taking insulin.
“If gestational diabetes is detected between the 26th and 28th weeks of pregnancy and the proper procedures are followed, these women can have normal, healthy babies,” Jovanovic said.
Hollingsworth said certain types of women seem more prone to gestational diabetes. They often are obese, over 30, have a strong family history of diabetes, have delivered a stillborn or given birth to another large infant.
Sinclair showed only one of these risk factors; she was 32. In her monthly prenatal visits to the doctor, she took a urine test, which was supposed to show whether she had any elevated levels of blood sugar. But high amounts of sugar in the blood don’t always spill over into the urine, reducing the value and accuracy of the test.
Dr. Steven Golde, assistant professor of obstetrics and gynecology at the University of Southern California, said: “What it boils down to is since you can’t rely on history or physical signs, you have to do a chemical (blood) test to screen for diabetes.”
Golde said the screen test is recommended to all county health clinics in Los Angeles. He also noted that Latinos have an incidence of gestational diabetes four times greater than the rest of the population.
Because Sinclair went to term without having the test, there is no precise way to determine whether she had the disease and what effect, if any, it had on the baby. A golden opportunity to monitor the mother’s health had slipped away, according to Hollingsworth.
The Best Test
“Pregnancy is the best test for diabetes,” she said. “If a woman doesn’t handle the metabolic stress of growing a new organ perfectly, she will develop a slightly higher than normal blood sugar.”
The high blood sugar is a result of too little insulin, the hormone produced by the pancreas that under ideal circumstances allows the body’s cells to use sugar in the blood. When the balance is upset, a diabetic’s body tries to remove the high blood sugar by flushing water out of the cells and through the kidneys. The diabetic often complains of thirst and frequent urination.
There is no way to measure a fetus’ blood sugar, but it is known that the pancreas of the fetus pours out its own insulin to offset the mother’s own high levels of blood sugar. The fetal insulin secretion clears the bloodstream of glucose, but the glucose is now stored as fat. After months of gestation, the fetus becomes obese, not unlike Sinclair’s baby.
At birth, the infant doesn’t automatically reduce its oversupply of insulin. As a result, the offspring develops a dangerously low blood sugar. (Sinclair’s baby appeared fine. Its blood levels were healthy.)
Hypoglycemia in the newborn may not be apparent on physical examination and has to be documented by measurement of low levels of blood glucose. Suggestive physical signs include twitching, nervousness or seizures. These signs may be absent or apparent only with careful observation.
Hospitals vary in their capability to perform and report blood glucose detection quickly. For this reason, specialists recommend that a meter to test blood glucose within the first 24 hours always be available at the maternity ward. Often an early oral feeding may be the only treatment required.
Jovanovic suggested that an infant’s oversupply of insulin may lead to early pancreatic exhaustion or diabetes later in the child’s adult life. There still is much speculation in this area. “Perhaps this is how familial diabetes occurs,” she said in a telephone interview. “If we can normalize the blood sugar of the mothers, maybe we can make normal babies.”