Guías clínicas para el ejercicio físico durante el embarazo / Clinical guidelines for physical exercise during pregnancy

De forma tradicional e histórica, las recomendaciones referidas al ejercicio físico durante el embarazo han estado basadas en cuestiones culturales y sociales, más que en evidencias científicas. De tal forma, la información científica disponible a través de guías de actuación profesional ha sido escasa o prácticamente inexistente. Ante esta situación, y con el ejercicio físico insertado en nuestra sociedad como un elemento básico de promoción de la salud, se hace importante disponer de unas guías prácticas que permitan a los profesionales, especialmente los sanitarios, disponer de recomendaciones para el ejercicio físico durante el embarazo basadas en sólidas evidencias científicas. El objetivo del presente estudio ha sido la elaboración de las primeras guías españolas de práctica clínica para el ejercicio físico durante el embarazo. El equipo de trabajo se formó producto de la solicitud de la Sociedad Española de Ginecología y Obstetricia (SEGO) al grupo de investigación Actividad Físico-deportiva en Poblaciones Específicas (AFIPE), de la Universidad Politécnica de Madrid; para la elaboración de las presentes guías estuvo formado por profesionales sanitarios, de las ciencias de la actividad física y del deporte y de la biblioteconomía y la documentación. El proceso metodológico desarrollado estuvo basado en el utilizado en las guías canadienses para la actividad física durante el embarazo, recientemente publicadas. Los resultados obtenidos permitieron elaborar unas recomendaciones básicas para el ejercicio físico durante la gestación, así como factores y situaciones que se deben tener en cuenta durante la práctica física en mujeres gestantes

Traditionally and historically, recommendations regarding physical exercise during pregnancy have been based on cultural and social issues, rather than on scientific evidence. Thus, the scientific information available through professional guidelines has been scarce or virtually non-existent. In this situation, with the physical exercise inserted in our society as a basic element of health promotion, it is important to have practical guidelines for professionals, especially health practitioners, with recommendations for physical exercise during pregnancy based in solid scientific evidence. The objective of this study has been the elaboration of the first Spanish clinical practice guidelines for physical exercise during pregnancy. The work team was formed based on the request of the Spanish Society of Gynecology and Obstetrics (SEGO) to the research group "Physical-sport activity in specific populations" (AFIPE), of the Universidad Politécnica de Madrid for the elaboration of the present guidelines, the work team was composed by health professionals, the physical activity and sports sciences professionals and one professional from the library and documentation science. The methodological process developed was based on the Canadian guidelines for physical activity during pregnancy, recently published. The obtained results allowed to establish basic recommendations for physical exercise during pregnancy, as well as factors and situations that should be considered during exercise in pregnant women

Translating Healthy Living Messages to Postpartum Women and Their Partners After Gestational Diabetes (GDM): Body Habitus, A1C, Lifestyle Habits, and Program Engagement Results From the Families Defeating Diabetes (FDD) Randomized Trial.

PURPOSE: The Families Defeating Diabetes intervention evaluated a postpartum healthy living program for women with recent gestational diabetes mellitus (GDM). DESIGN: Randomized controlled trial. SETTING: Tertiary centers in London, Calgary, and Victoria, Canada. PARTICIPANTS: Women with GDM and partners; 46% of eligible maternal participants agreed to participate. INTERVENTION: Interventional (INT) participants received a healthy living seminar at 3 months; access to a walking group/Website; biweekly e-mails. Control (CON) participants received a contemporary postpartum diabetes prevention handout. MEASURES: Maternal, partner, and offspring demographics at baseline, 3, and 12 months. ANALYSIS: Percentages of women losing ≥7% of postpartum weight were compared by χ2 testing; body habitus comparisons by analysis of covariance (ANCOVA); maternal A1C comparisons by unpaired t tests; participant outcome associations by Pearson correlation coefficients. RESULTS: Maternal participants were 170 (89 INT and 81 CON) with 63 partners (30 INT and 33 CON); 103 (73 maternal; 30 partners) were lost to follow-up; 57% of maternal participants completed 12 months; 33% INT women (n = 50) lost ≥7% weight versus 25% CON women (n = 47), P = .43. Interventional participant results did not correlate with accession of study elements. Maternal completion was significantly associated with partner involvement, breastfeeding, higher income, and education. Paternal weights correlated significantly with maternal and offspring weights. CONCLUSION: Families Defeating Diabetes outcomes were not significantly different for INT maternal or paternal participants versus CON participants. Secondary outcomes of future value included statistically significant positive associations between paternal participation, socioeconomic indicators, and maternal study completion, significant correlations between maternal, paternal, and offspring weights as well as insights into study component engagement.

Effect of exercise intensity and duration on capillary glucose responses in pregnant women at low and high risk for gestational diabetes.

BACKGROUND: Exercise may influence glucose metabolism during pregnancy. We examined the effect of exercise intensity and duration on capillary glucose responses in pregnant women at low and high risk for gestational diabetes mellitus (GDM) who followed a modified GDM meal plan. METHODS: Randomization occurred at study entry (16-20 weeks' gestation) into a low-intensity [30% heart rate reserve, low risk-30%I, n = 12; high risk-30%I, n = 11] or vigorous-intensity (70% heart rate reserve, low risk-70%I, n = 12; R-70%I, n = 11) exercise program with similar nutritional control. Exercise consisted of walking three to four times a week, gradually increasing time from 25 to 40 min/session. Free-living capillary glucose concentrations were measured once a week pre-exercise and post-exercise. RESULTS: Capillary glucose responses to exercise were strongly influenced by an interaction between GDM risk, exercise duration and exercise intensity (p = 0.006). Decreases in glucose concentrations were observed after 25 (4 ± 13%), 35 (21 ± 12%) and 40 min (15 ± 18%) of walking in high risk-30%I women, with the most noticeable decline after 35 and 40 min. In the high risk-70%I, glucose concentrations decreased significantly only after 25 (22 ± 14%) and 35 min (7 ± 23%) and increasing the exercise time attenuated glucose concentrations decline. In low risk women, regardless of exercise intensity and duration, decreases in glucose concentrations were significant and similar. CONCLUSION: To achieve the best decline in glucose concentrations, pregnant women who follow a modified GDM meal plan should walk for 25 min/session at vigorous intensity or for 35-40 min/session at low intensity if they are at risk for GDM and for at least 25 min at either low or vigorous intensity if they are at low risk for GDM.

Walking program of low or vigorous intensity during pregnancy confers an aerobic benefit.

Walking is the most popular activity during pregnancy and may confer an aerobic benefit. However, the minimum intensity threshold of a maternal walking program for an aerobic conditioning response is unknown. The purpose was to examine the effect of a walking program of a low-intensity (LI, 30% heart rate reserve, HRR) or vigorous-intensity (VI, 70%HRR) on maternal cardiorespiratory responses to a standard submaximal treadmill test. Normal weight pregnant women were randomized at study entry (16-20 weeks of gestation) to the LI (n=23) or VI (n=21) walking program, with nutritional control. Participants performed a steady-state treadmill exercise test at their prescribed intensity pre- and post-intervention (34-36 weeks) to evaluate changes in cardiorespiratory responses. Increasing body mass due to pregnancy was similar between the groups throughout the study. From pre- to post-intervention, relative (mL kg - 1 min - 1) VO2 and VCO2 during steady-state submaximal treadmill exercise did not change in the LI group but decreased in the VI group (- 1.25±2.71, p=0.02 and - 1.50±2.64, p=0.005, respectively). Both groups presented increases in oxygen pulse (p≤0.002). Our results showed that the energy cost of walking was not affected by the increase in maternal body weight in the LI group and was decreased in the VI group, suggesting an aerobic conditioning response in both groups, although the VI group presented a greater response. All women presented similar body mass throughout the intervention and delivered healthy babies, indicating that a prenatal walking program of low or vigorous intensity, combined with healthy eating habits, is safe and beneficial to the mother and fetus.

Aortic valve replacement and coronary artery surgery: determinants affecting early and long-term results.

BACKGROUND: We studied factors influencing early and late results in patients operated on for aortic valve replacement and coronary artery bypass graft. METHODS: 175 patients were retrospectively analysed over a 10-year period ending in December 2002. There were 135 males and 40 females with a mean age of 62.7 +/- 8.9 years; 109 were in NYHA class III/IV; 45 required an urgent operation, and 103 mechanical valves and 72 biological valves were implanted. RESULTS: There were 11 operative deaths (6.3 %). Statistical analysis (logistic regression) showed that previous myocardial infarction, poor NYHA class, and low LVEF had a significant effect on early death. There were 52 late deaths at a mean follow-up of 82.7 +/- 38.8 months. Using a Cox survival analysis for any causes, age, urgent operation, low LVEF, and creatinine had a strong impact on unfavourable late outcome. CONCLUSIONS: A combination of a patient-related factor (age), cardiac-related condition (low LVEF), co-morbid condition (renal dysfunction), and operative cause (urgent operation) is the most important predictor of late clinical outcome for this combined surgical procedure.

Discrete subaortic stenosis: long-term prognosis on the progression of the obstruction and of the aortic insufficiency.

BACKGROUND: We sought to determine the long-term rate of progression of left ventricular outflow tract (LVOT) obstruction and aortic insufficiency (AI) in adult patients operated on for discrete subaortic stenosis (DSS). METHODS: Between 1975 and 1995, 52 patients underwent surgery for DSS; their mean age was 25.4 +/- 14.8 years. Mean preoperative LVOT gradient was 72.8 +/- 25.7 mm Hg. Excision of the subaortic membrane was carried out in all patients, myectomy of the interventricular septum was additionally carried out in 8 patients (15.4 %), and aortic valve replacement (AVR) was performed in 15 patients (28.8 %). RESULTS: There were 2 operative deaths (3.8 %). Early postoperative LVOT gradient was 9.7 +/- 6.5 mm Hg. Follow-up ranged from 8.1 to 26.6 years. There were 8 late deaths (16.3 %), and mean LVOT gradient was 13.3 +/- 10.7 mm Hg. Five patients required reoperation for recurrent obstruction; 4 patients had a gradient of more than 30 mm Hg. The AI, in patients who did not undergo aortic valve replacement, did not substantially change during follow-up. CONCLUSIONS: DSS is a variable, unpredictable and progressive disease; recurrent obstruction may reappear despite the adequacy of surgical excision, and is not related to preoperative gradient. Mild AI remains substantially unchanged and AVR is indicated in severe AI.

Clinical outcome for on-pump myocardial revascularization in patients with mild renal dysfunction.

BACKGROUND: Coronary artery disease is the major cause of death in patients with chronic renal failure. We studied the early and long-term outcome of patients with mild chronic renal impairment, preoperative regular diuresis, and normal potassium levels having undergone pump myocardial revascularization. METHODS: From January 1992 to December 2000, 67 patients with serum creatinine level higher than 1.7 mg/dl and less than 2.5 mg/dl underwent on-pump myocardial revascularization. The patients were divided into 2 groups and treated with renal doses of dopamine in the postoperative or preoperative period, respectively. A homogeneous group of 100 patients was selected as control. RESULTS: There were no statistically significant differences in mortality and morbidity between the two groups A, while there was a significant difference in cardiac and respiratory complications, ICU stay and LOS between the A and B group in the early and long-term follow-up. Survival at 12-year follow-up is significantly higher in the B group. CONCLUSIONS: Patients with relatively mild renal insufficiency should be evaluated carefully for open cardiac surgery due to the significant increase in early and long-term morbidity and mortality.

Recreational exercise and occupational activity during pregnancy and birth weight: a case-control study.

OBJECTIVE: Our purpose was to investigate the impact of exercise and occupational activity on birth weight. STUDY DESIGN: This case-control study involved singleton infants at > or = 34 weeks' gestation without congenital anomalies. Case subjects had birth weights at <15th percentile for gestational age, and 2 control subjects were selected per case subject. Data were collected by self-completed questionnaire and analyzed by means of logistic regression. RESULTS: Relative to those who participated in structured exercise 3 or 4 times per week during the third trimester, the odds of lower birth weight were substantially increased for those who exercised > or = 5 times per week (adjusted odds ratio, 4.61; 95% confidence interval, 1.73-12.32) and modestly increased for those at the other extreme, who engaged in structured exercise < or = 2 times per week (adjusted odds ratio, 2.64; 95% confidence interval, 1.29-5.39). Other factors of importance to birth weight were maternal height, prepregnancy body mass, pregnancy weight gain, smoking in the third trimester, and nulliparity. CONCLUSIONS: Structured exercise frequency during late pregnancy is a determinant of birth weight.

Effect of maternal exercise on fetal and placental glycogen storage in the mature rat.

The purpose was to determine the effects of exercise on fetal and placental glycogen storage patterns at 20 days gestation (term 21 days) in mature (approximately 12 months of age) Sprague-Dawley rats. The exercise protocol consisted of treadmill running at 30 m min-1, on a 10 incline, for 60 min, 5 days per week, for 4 weeks prior to conception, which continued until day 19 of pregnancy. Exercise produced a significant reduction in fetal body weight, placental weight, and fetal organ weights (heart, kidney, brain, and liver) compared to sedentary control animals (p <.05). However, when fetal body size was taken into account, these differences disappeared, except for the fetal brain:body weight ratio, which was larger in the exercised animals compared to controls (p <.05). Fetal liver glycogen concentrations were significantly lower in exercised animals compared to nonrunning control animals (p <.05). These results demonstrate that exercise of mature rats may compromise fetal development and hepatic glycogen storage in the fetus.

Glycogen storage in fetuses of trained pregnant rats.

The purpose was to determine if running 30 m/min on a 10 degrees incline, 60 min/day for 5 days/ week altered fetal glycogen storage in prepregnancy trained rats. Animals that exercised for 3 weeks prior to pregnancy either continued the same exercise program until Day 19 of gestation (pregnant running group [PR]), or ceased exercising at conception (pregnant controls [PC]). A separate set of animals did not exercise either before or during pregnancy (pregnant nonrunning control group [PNRC]). On Day 20 of gestation, fetal organs and placenta were weighted and analyzed for glycogen concentration. Glycogen concentrations were not different in either fetal liver, heart, or placenta of PR rats compared to PNRC animals. However, fetal liver glycogen concentration was significantly lower in the fetal heart and liver of PC animals compared to glycogen measured in both PNRC and PR animals (p < .05). These results suggest that exercise of this intensity does not compromise fetal glycogen storage in trained pregnant rats. However, chronic prepregnancy exercise and then abrupt cessation of exercise at conception may compromise fetal growth and development.

The use of animal models in exercise and pregnancy research.

This article will discuss the use of animal models in exercise and pregnancy research. Although the ultimate goal is understanding mechanisms of change as a result of maternal exercise as they apply to pregnant women and the fetus, animal models deserve a place in research because of ethical constraints placed on experimentation on pregnant women. The risk identified through animal research should not be ignored if safe exercise guidelines are to be recommended to women who wish to engage in exercise during pregnancy.

Synthesis and biological evaluation of proline derivatives as potential angiotensin converting enzyme inhibitor.

The synthesis of a series of proline derivatives (1a-e and 2a-b) as pure isomers is described. These compounds were evaluated in vitro for their ability to inhibit angiotensin converting enzyme (ACE) and compared to the potency of captopril taken as a reference drug. They showed only a weak ACE inhibitory activity.

Cardiovascular monitoring of drug-resistant lymphoma patients treated with epoch chemotherapy plus high-dose verapamil in continuous-infusion.

High dose Verapamil (VP) infusion has been incorporated into cytotoxic chemotherapy in order to circumvent tumor cell drug-resistance. We have evaluated the cardiovascular side-effects produced by high dose VP associated to EPOCH chemotherapy in 12 patients with chemorefractory lymphoma. Continuous monitoring of right ventricular and pulmonary pressure and cardiac index was performed in three patients by a Swan-Ganz catheter. A slight reduction in cardiac index was observed 6 h after the beginning of VP infusion and was followed by spontaneous recovery within 12 h. First degree atrioventricular (AV) block was detected in 6/12 patients. Premature Ventricular Beats (PVB) occurred in one patient, and promptly disappeared after xylocaine administration. All patients experienced mild and transient hypotension, while severe hypotension was observed only in 1 patient, who promptly recovered when VP administration was discontinued. Hypokalemia was detected in 6 patients possibly as a consequence of transient activation of the renin-angiotensin system.

Recent advances in understanding maternal and fetal responses to exercise.

In the past decade, physical health fitness has become increasingly more important in the lives of women of child-bearing age. Many have made regular, and sometimes vigorous commitments to exercise programs. In 1985, the American College of Obstetricians and Gynecologists (ACOG) developed a set of guidelines for women who plan to exercise during pregnancy. Recommendations were based on available, but somewhat limited, scientific data and common sense. Since that time, researchers have learned a significant amount of new information about how a pregnant woman and her fetus respond to aerobic activity. The objective of this communication is to review recent investigations in this area. Specific topics include a) maternal responses to exercise, b) fetal responses to maternal exercise, c) animal research models, and d) pregnancy and physical conditioning. Our objectives are to present information that will a) stimulate new and innovative research designs for exercise and pregnancy studies, and b) add significantly to our knowledge and ability to develop safe and effective exercise programs for women who wish to remain physically active throughout a normal-term pregnancy.

Effect of water temperature on exercise-induced maternal hyperthermia on fetal development in rats.

The objective of this study was to determine if water temperature influenced exercise-induced hyperthermia in swim-trained pregnant rats and the resulting fetal development. Pregnant Sprague-Dawley rats with 6 weeks pre-pregnancy training were exercised daily from day 1 to day 18 of gestation in water that was 34.6 +/- 0.4 degrees C (Cool Water Swimmers--CWS) or 37.6 +/- 0.1 degrees C (Warm Water Swimmers--WWS), for one hour/day. During this time period another group of pregnant rats was immersed to the neck in warm water (37.6 +/- 0.2 degrees C) (Warm Water Controls--WWC). On day 19 of gestation all animals were sacrificed and fetal development assessed. Maternal exercise in warm water elevated maternal body core temperature by 2.3 +/- 0.1 degrees C above resting values, with an increase in fetal abnormalities compared to the same exercise intensity in cool water. Fifty-eight percent of the abnormal fetuses and 60% of the resorption sites were found in the WWS group. Of the abnormalities determined, 65% were from the WWS group and 45% of these fetuses showed micrencephaly. Results suggest cool water may regulate maternal body temperature during swimming exercise and that swimming in warm water should be avoided during gestation because of potential teratogenic effects.

Training effects on maternal and fetal glucose uptake following acute exercise in the rat.

The purpose of the present study was to determine the effects of chronic maternal exercise on glucose uptake in maternal tissues after one bout of treadmill running during late gestation in the rat and to determine the effects on glucose accumulation in the fetus and placenta. Trained pregnant animals (PR) ran at 30 m.min-1, on a 10 degrees incline for 1 h on day 20 of gestation with a similarly treated trained nonpregnant group (NPR). Immediately after the run the animals were infused with a bolus of 1 g.kg-1 body wt as a 50% dextrose solution mixed with 2-deoxy-D-[1-3H] glucose through a carotid catheter. Sedentary pregnant (P) and nonpregnant animals (C) were also infused with the solution after no food and water for the same time frame. After 60 min, tissues were analyzed for radioactivity. Radioactive tracer was augmented in the red gastrocnemius and soleus of the PR group and the soleus of P rats. However, tracer accumulation in the fetus and placenta of the trained animals was not different than P animals. These results indicate that acute exercise in trained animals increased glucose uptake in maternal skeletal muscles without compromising conceptus glucose accumulation.

Aerobic exercise in pregnancy: an update.

The endocrine effects of pregnancy cause striking changes in maternal metabolism, cardiovascular regulation, acid-base balance, and thermoregulation at rest and during standard submaximal exercise. The apparent purpose of these changes is to accommodate fetal needs in addition to those of the exercising woman. A significant body of evidence supports the hypothesis that healthy women can perform acute exercise of moderate intensity and duration without jeopardizing fetal well-being. Compiled studies also suggest that maximal oxygen uptake (VO2max, L.min-1) and the work rate at the onset of blood lactate accumulation (OBLA) are not significantly altered during the course of a normal pregnancy. However, some evidence suggests that maximal anaerobic power may be reduced. More information is needed on maternal cardiorespiratory function, carbohydrate metabolism, and acid-base balance at exercise intensities above OBLA and on fetal adaptability to strenuous maternal exercise. Recent studies support the view that moderate fitness conditioning can augment maternal metabolic and cardiopulmonary capacities without altering fetal development or pregnancy outcome. Implications of recent scientific studies for the design of aerobic exercise programs for pregnant women are discussed.

Effects of exercise on maternal glycogen storage patterns and fetal outcome in mature rats.

The purpose of the present study was to examine the effects of exercise on maternal glycogen storage patterns and fetal outcome in mature (approximately 12 months of age) Sprague-Dawley rats. The exercise consisted of treadmill running at 30 m.min-1, on a 10 degree incline, for 60 min, 5 days per week, for 4 weeks prior to pregnancy, which continued until day 19 of gestation. In mature animals, chronic exercise increased (p < 0.05) liver glycogen concentration in both pregnant and nonpregnant rats. In pregnant exercised animals, the glycogen concentration of the maternal liver increased almost twofold (p < 0.05) compared with the sedentary pregnant group. There was no difference in the amount of glycogen stored in the gastrocnemius or soleus muscles in response to training, pregnancy, or chronic maternal exercise in the mature rat. In the pregnant groups, there were fewer (p < 0.05) viable fetuses and more (p < 0.05) resorption sites than in young rats. In addition, exercise during pregnancy in the mature animal decreased (p < 0.05) fetal body weight. These results demonstrate that a conflict may exist between maternal exercise and fetal demands for energy in the mature rat. This conflict seems to favour the maternal system, as evidenced by the enhanced maternal liver glycogen storage and the negative effect on fetal growth.