gestational diabetes

Pokemon Go, exercise and gestational diabetes mellitus

~ quinlivanj ~ 4 Comments

IMG_0675

The recent Pokemon Go craze could have an unintentional benefit for women with pregnancy complicated by Gestational Diabetes Mellitus (GDM). The exercise involved in walking  around parks trying to capture Pokemon helps manage blood sugar levels and can lead to a reduced need for medication and diabetic complications.

The benefits of exercise in pregnancy

Regular exercise, particularly walking, is beneficial in pregnancy. Not only can regular exercise limit excessive gestational weight gain to international standards, it can also help prevent or manage GDM (1,2).

However, encouraging women to participate in regular exercise during pregnancy has proven challenging (3). Several randomised trials of exercise interventions in pregnancy have failed to demonstrate an effect on preventing excessive gestational weight gain or on the incidence or management of GDM, mainly due to poor compliance and low levels of participation by pregnant women in exercise programs (3,4,5).

So how might Pokemon Go help?

Women diagnosed with GDM are often asked to monitor their blood sugar level each morning (fasting blood sugar level) and again  2 hours after every meal (post prandial 2 hour blood sugar level). If the morning fasting blood sugar level, or the post prandial 2 hour blood sugar levels are higher than recommended targets (2,5), then medication may be necessary in order to reduce the risk of pregnancy complications such as abnormal fetal growth (macrosomia), excessive amniotic fluid (polyhydramnios), placental damage or fetal death in utero.

Regular exercise, even a 30 minute walk performed three times a week, can be helpful in regulating gestational weight gain and blood sugar levels.

This is where Pokemon Go might help.

By combining a regular walk with a game, it might encourage pregnant women to walk.

Maybe the manufacturers could invent pregnant Pokemon for our pregnant women to capture and provide an extra incentive!

Over to you game makers.

What else is new in gestational diabetes research?

Our research team recently published a paper on managing gestational diabetes (6). In this research study we explored whether it was possible to safely streamline the number of women who have to undergo antenatal investigations.

The particular focus of our recent study was on the value of fetal cardiotocography (CTGs) in managing GDM (6).

Different levels of risk in GDM?

The prevalence of GDM is rising due to increases in maternal obesity and a rise in sedentary lifestyles (6,7,8). If increasing numbers of pregnant women need increasing numbers of tests, our maternity systems will explode and costs of care will rise.

GDM pregnancies do have an increased risk of maternal and fetal complications such as gestational hypertension, pre-eclampsia, caesarean delivery, development of type 2 diabetes postpartum, fetal macrosomia, birth trauma and shoulder dystocia (6,7,8). The risk of maternal and fetal complications is particularly high in GDM pregnancies with poor blood sugar control (6,7,8).

Medications that reduce blood sugar levels in women with GDM include Insulin and Metformin. Medication is only prescribed when women cannot achieve ideal blood fasting and 2-hour post prandial blood sugar levels despite eating a diabetic diet and undertaking regular exercise.

Women who need medication to manage their blood sugar level are therefore  at higher risk of potential pregnancy complications compared to women who are able to manage their blood sugar levels with  diet and exercise.

Fortunately, 70% of women can manage their blood sugar levels with diet and exercise. This means only 30% of women diagnosed with GDM require medication.

Antenatal monitoring in GDM

Antenatal fetal monitoring is routinely performed in pregnancies complicated by GDM.

The two most common tests undertaken to monitor the wellbeing of the fetus are cardiotocographs (CTG) and ultrasound (9,10).

CTG can detect some pregnancies at risk of stillbirth, allowing for prompt further intervention (9,10).

How do CTGs work?

The heart rate of a fetus is determined by a balance between two different types of neurotransmitters (sympathetic and parasympathetic) that  act on the sinoatrial node in the heart (11).

This balance is mediated through a number of factors including catecholamines (11). If fetal pathology is present, and the fetus is unwell, this balance can be affected, and changes in fetal heart rate patterns can be observed on a heart rate trace – the CTG (11,12). 

A number of conditions are associated with abnormal CTG tracings. Specific CTG findings that suggest fetal hypoxia and acidosis include reduced variation in the baseline fetal heart rate and loss of rises in heart rate (accelerations) or development of drops in fetal heart rate after uterine contractions (late decelerations) (13).

Using CTGs in pregnancy complicated with GDM

As high levels of blood sugar can damage the placenta and lead to fetal pathology that makes the fetus at risk of low oxygen or death, CTGs have been used to monitor GDM pregnancies.

However, there is a lack of consensus on the frequency and commencement gestation of CTG monitoring in GDM pregnancies (14,15,16).

Results from our research

In our recent research publication, published in the Australian and New Zealand Journal of Obstetrics and Gynaecology, we evaluated the role of CTGs in managing pregnancy complicated by GDM (6). Click here to read to full paper.

We audited 1404 consecutive antenatal CTGs in women diagnosed with GDM to determine how often they resulted in a change in management.

Overall, we found that in women requiring medication in order to manage their blood sugar levels, 43 CTGs were required to change management.

In women who did not require medication to manage their blood sugar levels, but who had another factor complicating their pregnancy, 161 CTGs were required to change management.

However, in women who did not require medication to manage their blood sugar levels and who had no other pregnancy complication, CTGs did not change management.

Therefore, if pregnant women with GDM can achieve good blood sugar control with changes to their diet and exercise, they do not require CTG monitoring.

This further emphasises the need to promote a diabetic diet and regular exercise in women with GDM.

If Pokemon Go is a potential solution to help encourage pregnant women walk and exercise on a regular basis, then it might result in a cost saving to our health system through improved pregnancy outcomes, less need for prescribed medication in GDM pregnancy and less need for antenatal monitoring with CTGs.

Maybe we should run a trial?

References

  1. Quinlivan J. The Challenge to deliver cost effective care for patients with Gestational Diabetes Mellitus. Repro Syst Sexual Dis 2014; 2014(3):4. DOI: 10.4172/2161-038X.1000144
  2. International Association of Diabetes and Pregnancy Study Groups Recommendations on the Diagnosis and Classification of Hyperglycemia in pregnancy. Diabetes Care 2010;33:676-682.
  3. Quinlivan J Dietary component of lifestyle interventions helps obese pregnant women. Evidence Based Medicine 06/2012; 18:e4 doi:10.1136/eb-2012-100794.
  4. Quinlivan J, Juliania S, Lam L. Antenatal dietary interventions in obese pregnant women to restrict gestational weight gain to institute of medicine recommendations: a meta-analysis. Obstetrics and Gynecology 2011: 118(6): 1395-401.
  5. Nankervis A, McIntyre HD, Moses R, Ross GP, Callaway L, Porter C, et al. Consensus guidelines for the testing and diagnosis of gestational diabetes mellitus in Australia. Australasian Diabetes in Pregnancy Society; 2014.
  6. Jeffery T, Petersen RW, Quinlivan JA. Does cardiotocography have a role in the antenatal management of pregnancy complicated by gestational diabetes mellitus? ANZJOG 2016; DOI: 10.1111/ajo.12487.
  7. Landon MB, Mele L, Spong CY, Ramin SM, Casey B, Wapner RJ, et al. The relationship between maternal glycemia and perinatal outcome. Obstet Gynecol. 2011 Feb;117(2):218-24.
  8. HAPO Study Cooperative Research Group. Hyperglycemia and adverse pregnancy outcomes. N Engl J Med. 2008;358:1991-2002.
  9. Graves CR. Antepartum fetal surveillance and timing of delivery in the pregnancy complicated by diabetes mellitus. Clin Obstet Gynecol. 2007;50(4): 1007-1013.
  10. Kjos SL, Leung A, Henry OA, Victor MR, Paul RH, Medearis AL. Antepartum surveillance in diabetic pregnancies: predictors of fetal distress in labor. Am J Obstet Gynecol. 1995 Nov;173(5):1532-1539.
  11. McDonnell S, Chandraharan E. The Pathophysiology of CTGs and Types of Intrapartum Hypoxia. Current Women’s Health Reviews. 2013;9(3): 158-68.
  12. McDonnell S, Chandraharan E. Fetal Heart Rate Interpretation in the Second Stage of Labour: Pearls and Pitfalls. Br J Med Med Res. 2015;7(12): 957-70.
  13. Devoe LD, Jones CR. Nonstress test: evidence-based use in high-risk pregnancy. Clin Obstet Gynecol. 2002 Dec;45(4):986-992.
  14. Metzger BE, Buchanan TA, Coustan DR, de Leiva A, Dunger DB, Hadden DR, et al. Summary and Recommendations of the Fifth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes Care. 2007 Jul;30(S2) :S251-60.
  15. Landon MB, Vickers S. Fetal surveillance in pregnancy complicated by diabetes mellitus: is it necessary?. J Matern Fetal Neonatal Med. 2002 Dec; 12(6):413-416.
  16. Loomis L, Lee J, Tweed E, Fashner J. What is appropriate fetal surveillance for women with diet-controlled gestational diabetes?. J Fam Pract. 2006 Mar;55(3):238-240.

 

What’s new about gestational diabetes?

~ quinlivanj ~ 3 Comments

IMG_0675.JPGGestational diabetes is a common medical complication of pregnancy (1-5). It is an important condition as failure to diagnose and treat gestational diabetes can lead to poor pregnancy outcomes, and in severe cases, fetal death in utero may occur. However, with accurate diagnosis and management, outcomes are excellent.

There have been some changes in the way gestational diabetes is diagnosed and managed.

1. The diagnosis of gestational diabetes has changed

The original diagnosis of gestational diabetes was developed nearly 50 years ago (3). In 2010 there was a recommendation by the International Diabetes and Pregnancy Study Groups that the diagnosis of gestational gestational diabetes should change (4,5). The recommendation arose from a study called HAPO (Hyperglycaemia and pregnancy outcomes)(5). The HAPO tidy correlated blood sugar levels in pregnancy with poor outcomes in mothers and babies and formulated new cut off values for blood sugar levels in pregnancy (4,5).

Six years later, not all countries and clinicians have adopted the new recommendations. However, our research suggests the new diagnostic criteria are associated with improved outcomes (6).

Gestational diabetes is diagnosed on a blood test performed between 24 and 30 weeks of pregnancy. The diagnostic test is called a glucose tolerance test and involves an overnight fast, followed by a fasting blood sugar test. Women then drink a measured amount of glucose syrup and 1 and 2 hours later have further blood sugar tests.

The new diagnostic criteria are (4):

fasting level greater than 5 mmol/l

1 hour sugar level greater than 10mmol/l

2 hour sugar level greater than or equal to 8.5mmol/l.

2. Importance of diet

The importance of diet in the management of gestational diabetes has never been clearer.

The majority of women who adopt a diabetic diet will require no additional treatment.

Many maternity units will refer women diagnosed with gestational diabetes to a dietician for advice on a diabetic diet. However, information is also widely available on the Internet, and in libraries and from diabetes associations.

Monitoring blood sugar levels in conjunction with diet is important as no two people respond to a food source in the same way.

As a clinician I have seen women eat the same meal and one will have a normal blood sugar level and the second an elevated level. Therefore it is important to monitor your sugar levels along with your diet to assess how your body responds to particular foods. This will help you identify safe foods and those you should avoid.

Blood sugar levels are monitored using a finger prick test. Machines to record the blood sugar level may be hired from chemists.

3. Medication for gestational diabetes

If medication is required (about 30% of women) then traditionally this would have been Insulin.

However, increasingly Metformin, an oral medication, is prescribed. There are good safety studies for Metformin.

Your specialist will advise whether Metformin, Insulin or a combination of the two is required.

4. Monitoring the pregnancy

Because gestational diabetes is associated with an increased risk of pregnancy complications, additional monitoring of the pregnancy is required. This is usually in the form of ultrasound examinations and fetal cardiotocograph tests (CTGs).

Ultrasound examinations are ordered to assess fetal growth and placental health. The pathology in gestational diabetes arises in the placenta. High blood sugar levels damage the delicate blood vessels in the placenta, causing sugar to flood across into the baby. The baby’s developing hormone system responds to the high sugar level by releasing growth factors. This causes abnormal growth of the baby which is detected on ultrasound as an increase in the abdominal circumference.

In more severe cases, the delicate placental blood vessels are so damaged that the placental circulation shuts down, and the baby ends up being starved of nutrients, and becomes growth restricted.

Medical staff will usually plot the developing baby’s growth on a chart to assess if the overall growth of the baby, and the relative growth of the head, abdomen and femur bones are in proportion.

The ultrasound examination will also inform medical staff about blood flow in the placenta and if growth is abnormal, will record the blood flow within the baby’s head. Blood flow readings are called doppler studies. The results of doppler studies can assist in guiding  delivery management.

Cardiotocograph tests may also be ordered to monitor the well being of the developing baby. We are currently finalising a study to investigate the optimal strategy to use CTGs in pregnancy complicated by gestational diabetes. However, our preliminary results suggest the tests should be reserved for pregnancies where medication is required in addition to diet, or where other complications have been noted.

5. Timing of delivery

There is no agreed gestation at which women with gestational diabetes should deliver. However, many people now believe that if the pregnancy has been managed with diet alone, and blood sugar levels have been controlled, and the baby’s growth is normal, then the pregnancy can progress to term and normal birth without the need for intervention. However, many centres still offer delivery at 40 weeks.

If the pregnancy is complicated because medication was required in addition to diet, or the baby’s growth was abnormal, or a CTG was abnormal, then earlier delivery is required.

6. Follow up after delivery

All women who were diagnosed with gestational diabetes should have a follow up assessment within six months of delivery. This should involve a repeat glucose tolerance test. In our clinic, we also screen for thyroid and cholesterol abnormalities. We have found women with gestational diabetes have an elevated risk of developing type 2 diabetes, thyroid and cholesterol problems (7).

Sadly, many women fail to receive postnatal follow up and a valuable opportunity to improve their long term health through early diagnosis of chronic disease is wasted.

In summary

Gestational diabetes is easy to diagnose and manage. Most women will only require dietary changes, monitoring of blood sugar levels and some additional investigations.

It is important to screen and treat as otherwise pregnancy complications can harm mother and baby.

References

1. American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes care 2009; 32(S1): S62-S67.

2. Metzger BE, Coustan DR: The organizing committee. Summary and recommendations of the Fourth International Workshop-Conference on Gestational Diabetes Mellitus. Diabetes care 1998; 21(S2): B161-B167.

3. O’Sullivan JB, Mahan CM. Criteria for oral glucose tolerance test in pregnancy. Diabetes 1964;13: 278-285.

4. International Association of Diabetes and Pregnancy Study Groups Recommendations on the Diagnosis and Classification of Hyperglycemia in pregnancy. Diabetes Care 2010; 33: 676-682.

5. Metzger BE, Lowe LP, Dyer AR et al. The HAPO Study Cooperative Research Group. Hyperglycemia and Adverse pregnancy outcomes. N Engl J Med 2008; 358: 1991-2002.
6. Silbartie P, Quinlivan JA. Implementation of the International Association of Diabetes and Pregnancy Study Groups Criteria: Not Always a Cause for Concern. Journal of pregnancy 12/2015; 2015(2):1-5. DOI: 10.1155/2015/754085

7. Quinlivan JA, Lam D. Cholesterol abnormalities are common in women with prior gestational diabetes. J Diabetes Metab 2013; 4(4): 255. doi: 10.4172/2155-6156.10000255.