Personal Health Navigator

Pregnancy is the ultimate stress test on the body

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Written by Paul Taylor

Question:  I’m pregnant and, to my surprise, I now have gestational diabetes. Is this a common problem for pregnant women?

Answer:  In many respects, having a baby is the ultimate stress test.  “During pregnancy, virtually every organ system in the body has to work harder in order to support the needs of the developing fetus,” says Dr. Baiju Shah, head of endocrinology at Sunnybrook Health Sciences Centre in Toronto.

Most of the time, everything goes smoothly. But up to 10 per cent of women are not able to keep up with these extra demands and develop some type of metabolic problem such as gestational diabetes.

Usually, the condition goes away immediately after the birth of the child. But it can be a harbinger of things to come. “Pregnancy is like a window into your metabolic future,” explains Dr. Shah.  If there is an underlying weakness, it may reveal itself for the first time during pregnancy – and come back later in life.

In fact, about 20 per cent of women diagnosed with gestational diabetes will go on to develop type 2 diabetes within a decade, he says.

Before delving deeper into future risks, it’s worthwhile considering what actually happens in pregnancy to trigger this condition.

The first thing you need to know is that insulin – a hormone produced in the pancreas – helps to move glucose (or sugar) from the bloodstream into the body’s cells where it is used for energy.

Mid-way through pregnancy, women will begin to experience insulin resistance as a result of hormones released by the placenta, the organ that supplies oxygen and nutrients to the growing fetus, says Dr. Lorraine Lipscombe, director of endocrinology at Women’s College Hospital in Toronto.

Insulin resistance essentially means that the pregnant woman’s insulin becomes less effective at moving glucose into her cells. In other words, her cells “resist” the insulin.

This likely happens to make sure the fetus is well supplied with glucose. But the mom’s cells needs a sufficient amount of glucose, too. So, her pancreas starts pumping out more insulin to compensate for its diminished effectiveness.

However, some pregnant women are unable to produce enough extra insulin. As a result, high levels of glucose begin to build up in their bloodstream.  At this point, they are now considered to have gestational diabetes, which is bad for both mother and fetus.

In particular, elevated levels of glucose in the mother’s bloodstream start flowing across the placenta into the fetus, which in turn, causes the fetus to produce more insulin to process the high levels of sugar.

If left unchecked, all the calories from the extra glucose – plus the insulin, which is a growth stimulant – can lead to a bigger than normal baby.  This raises the risk of complications when it comes time to give birth. In some cases, a caesarian section may be needed to deliver a super-sized baby.

Canadian medical guidelines call for women to be tested for gestational diabetes between 24 and 28 weeks of pregnancy.  If the amount of glucose in the blood is excessively high, efforts are made to bring it down to a healthier range.

Dietary changes and increased physical activity can often be used to successfully manage blood glucose levels, says Dr. Lipscombe.

But about 40 per cent of these women will need to take medications such as insulin injections or Metformin, a drug that’s usually prescribed to people with type 2 diabetes.

Gestational diabetes also raises another concern. Women who get this condition are at a heightened risk of developing high blood pressure during pregnancy. Some of them will get a more serious blood pressure-related condition called preeclampsia, which can cause organ damage.

After giving birth, though, most women return to their pre-pregnancy metabolic condition. Blood sugar and blood pressure levels go back to normal and they are usually discharged from medical care.

But both Dr. Shah and Dr. Lipscombe think more should be done to make these women aware that they may be predisposed to developing diabetes and cardiovascular disease at an early age.

“The message gets lost that this is actually something that needs to be followed more closely,” says Dr. Lipscombe.

Research shows that lifestyle changes – such as eating a balanced diet, maintaining a healthy weight and getting regular exercise – can help keep these ailments at bay.

Yet it can be especially challenging for new moms to focus on their health while caring for an infant.

So, Dr. Lipscombe is heading up a study aimed at helping them adopt a healthier lifestyle. Those taking part in the study receive individual counselling and frequent follow-up telephone calls to stay on track.

“There are things that women can do to reduce their risks,” says Dr. Lipscombe. She hopes more research will lead to a personalized approach to supporting the post-partum health of this vulnerable group.

 

About the author

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Paul Taylor

Paul Taylor, Sunnybrook’s Patient Navigation Advisor, provides advice and answers questions from patients and their families, relying heavily on medical and health experts. Email your questions to AskPaul@sunnybrook.ca
and follow me on Twitter @epaultaylor