Exercise as it relates to Disease/Safe Exercise for Gestational Hypertension
Cardiovascular disease (CVD) is one of the leading causes of death in Australia, accounting for 34% of all deaths in 2007-08. The 2007-08 National Health Survey (NHS) reported Hypertension as the most common CVD, reported by 9% of the population. The Australian Bureau of Statistics (ABS) reported CVD as the highest health expenditure of all disease groups, accounting for 11.3% of Australia’s total allocated health spending 
Hypertension is a cardiovascular disorder characterised by a systolic blood pressure of at least 140 mmHg and/or a diastolic blood pressure of at least 90 mmHg. To avoid ‘white coat’ hypertension, it is commonly measured using 24 hour ambulatory methods. Gestational hypertension is the new-onset of hypertension, typically presenting 20 weeks after gestation, and involves little to no urine protein content. Some women progress from Gestational hypertension to Preeclampsia. Preeclampsia is defined as gestational hypertension, plus proteinuria (300 mg or more per 24-hourperiod). This complication occurs in roughly 2-8% of women but however is manageable upon early detection. A complication exists here because physical symptoms often present late or not at all. Literature has reported that insulin resistance in early stages of pregnancy may serve as predisposition marker for gestational hypertension.
Pregnancy and Hypertension
Gestational hypertension is different to pre-existing Hypertension; however both carry risks for the mother and the baby. Hypertension in pregnancy can cause strokes, seizures, renal damage and cardiovascular disease. Different demographics will experience higher instance of hypertension during pregnancy. The Australian Bureau of Statistics (ABS) found that in 2008, 14% of birth-mothers of Aboriginal and Torres Strait Islander high blood pressure during their pregnancy.
Due to the high pressure in the vascular network, capillary walls are damaged and blood flow is hampered. Neural tube defects and lack of blood flow can also cause maternal hyperthermia. Capillaries to the womb and placenta carrying blood and therefore oxygen and nutrients to the foetus are therefore not efficient. Sufficient blood flow is needed to ‘feed’ the growing foetus. Complications here can result in poor growth, pre-term birth or even loss of pregnancy.
Women diagnosed with Gestational Hypertension and/or Preeclampsia require close monitoring of both maternal and foetal conditions. Management of gestational hypertension includes:
- Bed Rest
- Blood Pressure Medications (anti-hypertensive drugs)
- Foetal and Maternal Monitoring (daily blood pressure readings)
- Hospitalisation (severe)
Commonly the mother’s blood pressure will return to normal within the first week postpartum. If blood pressure is still elevated, supplemented magnesium sulphate and antihypertensive drugs are given. Daily blood pressure measurements are conducted, until there are no signs or symptoms of hypertension.
Exercise Prescription for Gestational Hypertension
Current literature suggests that women with gestational hypertension need to limit physical activity. However, the American College of Obstetricians and Gynaecologists (ACOG) listed pregnancy induced hypertension in a list for absolute contraindications to aerobic exercise during pregnancy. Literature suggests that regular physical activity within the first 20 weeks of gestation may prevent or reduce the risk of developing Hypertension and related hypertensive disorders during the latter period of gestation.
Hypertension and Exercise
Non aerobic-exercise such as yoga has been shown to decrease blood pressure in non-pregnant hypertensive patients. It has been suggested this and other antenatal exercises could also reduce the risk of developing gestational hypertension along with aerobic exercise preconception. Further research could be conducted into the effects of yoga and antenatal exercises on blood pressure in pregnant women to possibly predict the effects on pregnant hypertensive patients
Pregnancy and Exercise
Exercise should not involve ballistic movements or too much thermal/environmental stress. As the gestational period continues, exercise intensity can decrease as long as physical activity is maintained. Too much exercise or high intensity exercise causes skeletal muscle and the foetus to compete for blood flow and is related to pre-term births. Most studies predicted exercise intensity using % max heart rates varying depending on age and period of gestation. It is important to note that in healthy individuals, exercise during pregnancy is considered beneficial to both mother and foetus, and is encouraged. The American College of Sports Medicine (ACSM) recommend moderate intensity aerobic exercise for a minimum of 30 minutes per day.
Exercise during pregnancy with non-hypertensive subjects not only reduces the risk of developing hypertension but has a number of other benefits including: decreased adipose tissue accumulation associated with pregnancy due to increased sedentary activity, decreased labour pain, decreased triglycerides and inflammatory cytokines, decreased insulin resistance, enhanced placental growth and vascularity, increase in plasma volume and cardiac output, reduction in emotional stress and anxiety 
- Exercising with Gestational Hypertension is not encouraged as it only increases blood pressure and can causes damage to mother and foetus
- Monitoring of blood pressure, rest and anti-hypertensive drugs are the main therapy for Gestational Hypertension
- Best strategy is prevention through light aerobic exercise pre-conception and most importantly, during 1st half of pregnancy
- Possible room for research into other coping strategies (non-aerobic exercise)
- Contact your physician/obstetrician and seek medical evaluation and clearance before undertaking any exercise regime
Women and Newborn Health Service – Kind Edward Memorial Hospital, Clinical Guidelines: Obstetrics and Midwifery Guidelines. Medical Management of Hypertension in Pregnancy. http://www.kemh.health.wa.gov.au/development/manuals/O&G_guidelines/sectionb/2/5146.pdf
Guide to Management of Hypertension http://www.heartfoundation.org.au/SiteCollectionDocuments/HypertensionGuidelines2008to2010Update.pdf
- Australian Bureau of Statistics, 2008. 2007-2008 National Health Survey
- Sibai, B. M. "Diagnosis and Management of Gestational Hypertension and Preeclampsia." American College of Obstetrics & Gynecology. 2003. 102(1), 181-92
- Meher S, Duley L. Exercise or other physical activity for preventing pre-eclampsia and its complications. Cochrane Database Syst Rev 2006;2
- Carpenter, M. W. "Gestational Diabetes, Pregnancy Hypertension, and Late Vascular Disease." Diabetes Care 30.Supplement_2. 2007. S246-250
- Seely, E. W., and C. G. Solomon. "Insulin Resistance and Its Potential Role in Pregnancy-Induced Hypertension." Journal of Clinical Endocrinology & Metabolism. 2003. 88(6), 2393-398.
- Heart foundation of Australia, 2012. Cardiovascular Conditions: High blood pressure. http://www.heartfoundation.org.au/your-heart/cardiovascular-conditions/Pages/blood-pressure.aspx
- Wolfe LA, Hall P, Webb KA, Goodman L, Monga M, McGrath MJ. Prescription of aerobic exercise during pregnancy. Sports Med 1989 Nov;8(5):273-301
- Ferrazani S, DeCarolis S, Pomini F, Testa AC, Mastromarino C, Caruso A. The duration of hypertension in the puerperium of preeclamptic women: Relationship with renal impairment and week of delivery. Am J Obstet Gynecol. 1994. 17:506–12.
- Artal, R., and M. O'Toole. "Guidlines of the American College of Obstetricians and Gynecologists for Exercise during Pregnancy and the Postpartum Period." Br J Sports Med. 2003. 37, 6-12
- ACOG Committee. Opinion no. 267: exercise during pregnancy and the postpartum period. Obstet Gynecol 2002. 99,171–3.
- Marcoux S., Brisson J, Fabria J. The effect of leisure time physical activity on the risk of pre-eclampsia and gestational hypertension. Journal of Epidemiology and Community Health. 1989. 43, 147-152.
- Saftlas, A. F., N. Logsden-Sackett, W. Wang, R. Woolson, and M. B. Bracken. "Work, Leisure-Time Physical Activity, and Risk of Preeclampsia and Gestational Hypertension." American Journal of Epidemiology. 2004 160(8), 758-65.
- Larsson L, Lindqvist PG. Low‐impact exercise during pregnancy–a study of safety. Acta Obstet Gynecol Scand 2005; 84(1):34-38.
- Mottola MF, Davenport MH, Brun CR, Inglis SD, Charlesworth S, Sopper MM. VO2peak prediction and exercise prescription for pregnant women. Med Sci Sports Exerc 2006; 38(8):1389.
- Pate RR, Pratt M, Blair SN, et al. A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. AMA. 1995. 273, 402–7.
- Melzer K, Schutz Y, Boulvain M, Kayser B. Physical Activity and Pregnancy: Cardiovascular Adaptations, Recommendations and Pregnancy Outcomes. Sports Medicine 2010 06; 40(6):493-507.