T H E
C I E N C E
O F
L I F E S T Y L E
C H A N (
Pregnancy; Fitness; Weight Control
A Program of Exercise Throughout Pregnancy. Is It Safe to Mother and Newborn? Ruben Barakat, PhD; Maria Perales; Mariano Bacchi; Javier Coteron, PhD; Ignacio Refoyo, PhD Abstract Purpose. The aim o f the present study was to examine the influence o f a program o f moderate physical exercise throughout pregnancy on maternal and fetal parameters. Design. The study design was a randomized controlled trial. Setting. The study took place at the Hospital of Fuenlabrada in Madrid, Spain. Sample. Analyzed were 200 pregnant women (31.54 ± 3 .86 years), all o f whom had uncomplicated and singleton gestation. O f these subjects, 107 were allocated to the exercise group (EG) and 93 to the control group (CG). Intervention. Women from EG participated in a physical conditioning program throughout pregnancy, which included a total o f 55- to 60-minute weekly sessions, 3 days per week. Measures. Pregnancy outcomes. Maternal: gestational age, weight gain, type o f delivery, blood pressure during pregnancy, gestational diabetes (n /% ). Fetal: birth weight, birth size, head circumference, Apgar score, p H o f umbilical cord. Analysis. Student’s unpaired t-test and %2 test were used; p values o f < .05 indicated statistical significance. Cohen’s d was used to determine the effect size. Results. There were significantly more pregnant women in the CG who gained excessive weight during their pregnancies than in the EG group (CG: N = 31, 35.6% versus N = 22, 21.2% ; x~ = 4.95; p= .0 2 ). The effect size was small (Phi value = 1 6 ). Other pregnancy outcome showed no differences between groups. Conclusion. A regular and moderate physical exercise program throughout pregnancy is not a risk to maternal and fetal well-being, and it helps to control excessive weight gain. (Am J Health Promot 2014;29[l]:2-8.) Key Words: Physical Exercise, Pregnancy Outcomes, Maternal, Weight Gain, Prevention Research. Manuscript format: research; Research purpose: intervention testing; Study design: randomized trial; Outcome measure: behavioral; Setting: health care; Health focus: physical activity; Strategy: behavior change, culture change; Target population age: adults; Target population circumstances: education
Ruben Barakat, PhD; Maria Perales; Javier Coteron, PhD; and Ignacio Refoyo, PhD, are on the faculty of Physical Activity and Sport Sciences at the Technical University o f Madrid, Spain. Mariano Bacchi is on the faculty of Physical Activity and Sport at the University of Flores, Buenos Aires, Argentina. Send re p rin t requests to R uben B arakat, PhD, Physical Activity a n d S p o rt Sciences, Technical U niversity o f M adrid, M artin F ierro 7, 28040 M adrid, Spain; barakatruben@ gm ail.com . This manuscript was submitted January 31, 2013; revisions were requested March 26, April 16, and April 25, 2013; the manuscript was accepted fo r publication May 16, 2013. Copyright © 2014 by American Journal of Health Promotion, Inc. 0890-1171/14/$ 5.00 4- 0 DOI: 10.4278/ajhp. 130131-QUAN-56
2
American Journal of Health Promotion
PURPOSE Pregnancy is a unique process in which nearly all of the body’s control systems are modified to maintain both maternal and fetal homeostasis.1 With physical exercise (PE) becoming an integral part of many women’s lives, the question remains as to whether this exercise has any adverse effects on pregnancy outcomes.23 In theory, the addition of PE throughout pregnancy may represent a significant challenge to both the maternal and fetal well being because the dual stresses of pregnancy and exercise may create conflicting physiological demands and thus adversely affect pregnancy out comes.4 The effects of exercise during preg nancy have been studied extensively. A dearth of well-controlled randomized studies has led to conflicting evidence as to the impact of exercise on mater nal and fetal parameters. There is a lack of consensus regarding the po tential long-term risks or benefits for the offspring of exercising mothers.5 Relative to maternal outcomes, tra ditionally preterm delivery (birth 6 MET (>21 mL 0 2/k g /m in ) 34 is p ru d en t because the definition of m oderate and vigorous should be based on each individual’s own aerobic capacity. Thus, basing exercise intensity on percentage of h eart rate and the Borg Rating of Perceived Exertion Scale (Borg’s RPE) is best when prescribing exercise in tensity in all individuals, including p reg n an t women. 35 Aerobic exercise in which large muscle groups are used, including walking, stationary cycling, aquatic exercise, or low-impact aerobics, is recom m ended for low-risk pregnant w om en.36 Many studies have shown, however, that there seems to be a discrepancy between these recom m en dations and what women actually do.37,38 T he aim of the present study was to exam ine the influence of a program of m oderate physical exercise throughout pregnancy on m aternal and fetal pa ram eters. We hypothesize th at physical exercise during pregnancy would not be associated with altered pregnancy outcomes.
METHODS Design T he p resent study was a random ized controlled trial (RCT, NCT 01696201).
Sample Subjects were 282 pregnant women living in Madrid, Spain, who were approached and inform ed of the study and inclusion criteria at their first prenatal visit by health care providers (midwives, obstetricians, and family doctors) at 6 to 7 weeks of pregnancy. Pregnant women who underw ent their first ultrasound exam ination in Hospi tal Universitario de Fuenlabrada at 10
to 12 weeks of pregnancy were offered the opportunity to participate follow ing a random ization process. A total o f 251 participants who agreed to participate were random ly allocated between two groups: 137 to the exercise group (EG) and 114 to the control group (CG). All o f the patients had uncom plicated and singleton ges tations, and their m ean age was 31.54 ± 3.86 years. W ritten inform ed consent was ob tained from each participant. The study was approved by the Research Ethics Com m ittee of Hospital Univer sitario de Fuenlabrada (Madrid, Spain) and was conducted according to the ethical guidelines o f the Declaration of Helsinki, which was last m odified in 2008. W omen presenting any type of ab solute obstetrical contraindication to exercise as suggested by American College of Obstetricians and Gynecol ogists (ACOG)31 were excluded (see below). O ther exclusion criteria were as follows: n o t planning to give birth in the obstetrics departm ent of the study hospital, n o t receiving medical follow up throughout the pregnancy, partici pating in another physical activity program , o r having a high level of pregestational physical exercise PE (four or m ore times per w eek). Be cause participating in another struc tured exercise program was an exclusion criterion, this was verified in EG at the beginning o f the study. Women in the CG confirm ed (via telephone interview) that they did not participate in a structured exercise program th roughout th eir pregnan cies. ACOG absolute obstetrical contrain dications for exercise are as follows: • Hemodynamically significant heart disease • Restrictive lung disease • Incom petent cervix • Multiple gestation • R uptured m em branes • P re e c a lm p sia /p re g n a n c y -in d u c e d hypertension For allocation of the participants, a com puter-generated list of random num bers was used. T hree different authors were responsible for carrying out the random ization process, which consisted of a sequence generation,
September/October 2014, Vol. 29, No. 1
3
allocation concealm ent, and im ple m entation. Sample Size To detect a difference in percentage o f women with a preterm delivery of 15%, with a two-sided 5% significance level and a power of 80%, the m ini m um nu m b er of 88 p reg n an t per group was necessary, given an antici pated d ro p o u t rate of 15%.39 Intervention The women who were random ly assigned to the exercise group were invited to participate in a supervised physical conditioning program that included three 55- to 60-minute ses sions p er week that began between 9 and 13 weeks o f gestation and contin ued until the end o f the third trim ester (weeks 39-40). Every session started with 5 m inutes o f walking and static stretching of most muscle groups to warm up. This warm up was followed by toning and jo in t m obilization exercises, aerobic dance, and specific exercises that targeted the m ajor muscle groups in the legs, buttocks, and abdom en to stabilize the lower back (30 m inutes); balancing exercises were also included (10 m in utes). Every session concluded with pelvic floor muscle training (10 m in utes) and a cool-down period (5 m inutes). Exercises that involved the Valsalva maneuver, extrem e stretching, jo in t overextension, ballistic move ments, and ju m p in g were specifically avoided. Furtherm ore, the exercises were perform ed in the supine position for no longer than 2 minutes. Light- to m oderate-intensity aerobic activity was prescribed, with the goal of achieving a 55% to 60% maximal heart rate. To allow the participants to identify the intensity required for the aerobic exercise, the h eart rate was shown on a poster after being calcu lated individually for each woman based on the trimester, physical condi tion, and age using the Karvonen form ula.40 T he intensity was also ad ju sted based on the Borg Scale rat ings,41 which m easured the m aternal rate o f perceived exertion. According to the National Board o f H ealth in Denm ark, p reg n an t women should engage in exercise according to Borg Scale level 12 to 13 (corresponding to m oderate/som ew hat hard exercise).44
4
American Journal of Health Promotion
All of the subjects wore a heart rate (HR) m onitor (Accurex Plus, Polar Electro OY, Kempele, Finland) during the training sessions to ensure that the exercise intensity was light to m oder ate. To maximize patient safety and adherence to the training program and its efficacy, all o f the sessions were supervised by a qualified fitness spe cialist (working with groups o f 10-12 subjects), with the assistance of an obstetrician, and were accom panied by music; the exercises were perform ed at the University Hospital of Fuenlabrada in a spacious, well-lit room u n d er favorable environm ental conditions (altitude 600 m, tem perature 19-21°C, hum idity 50-60% ). An adequate intake of calories and nutrients was ensured for each participant before the start of the exercise session. Women in the CG did not exercise during this period; they received the usual inform ation provided by their midwives o r health care professionals. Measures T he following characteristics and pregnancy outcom e were considered: m aternal age, body mass index (BMI), sm oking habits, parity, gestational age, m aternal weight gain (kg) and “ma ternal weight gain according to Insti tute o f Medicine (IOM) recom m endation,”43 preterm delivery, type of delivery, blood pressure, birth size, head circum ference, birth weight, and Apgar score. All data were collect ed in the medical report that pregnant women generated by their usual visits with health care providers (midwives, obstetricians, and family doctors) dur ing pregnancy. Analysis S tudent’s unpaired f-test was used to exam ine the differences in the de scriptive characteristics between the intervention and control groups and to know the effect o f the exercise pro gram on pregnancy outcom e (gesta tional age, m aternal weight gain, blood pressure, birth size and weight, head circum ference, Apgar scores and pH of umbilical cord). T he results are pre sented as the means ± standard deviation (SD). For the evaluation of delivery type, m aternal weight gain according to recom m endations and o ther m aternal
characteristics (e.g., parity, smoking status, educational level, prepregnancy BMI), y2 tests were used; p values of
C I E N C E
O F
L I F E S T Y L E
C H A N (
Pregnancy; Fitness; Weight Control
A Program of Exercise Throughout Pregnancy. Is It Safe to Mother and Newborn? Ruben Barakat, PhD; Maria Perales; Mariano Bacchi; Javier Coteron, PhD; Ignacio Refoyo, PhD Abstract Purpose. The aim o f the present study was to examine the influence o f a program o f moderate physical exercise throughout pregnancy on maternal and fetal parameters. Design. The study design was a randomized controlled trial. Setting. The study took place at the Hospital of Fuenlabrada in Madrid, Spain. Sample. Analyzed were 200 pregnant women (31.54 ± 3 .86 years), all o f whom had uncomplicated and singleton gestation. O f these subjects, 107 were allocated to the exercise group (EG) and 93 to the control group (CG). Intervention. Women from EG participated in a physical conditioning program throughout pregnancy, which included a total o f 55- to 60-minute weekly sessions, 3 days per week. Measures. Pregnancy outcomes. Maternal: gestational age, weight gain, type o f delivery, blood pressure during pregnancy, gestational diabetes (n /% ). Fetal: birth weight, birth size, head circumference, Apgar score, p H o f umbilical cord. Analysis. Student’s unpaired t-test and %2 test were used; p values o f < .05 indicated statistical significance. Cohen’s d was used to determine the effect size. Results. There were significantly more pregnant women in the CG who gained excessive weight during their pregnancies than in the EG group (CG: N = 31, 35.6% versus N = 22, 21.2% ; x~ = 4.95; p= .0 2 ). The effect size was small (Phi value = 1 6 ). Other pregnancy outcome showed no differences between groups. Conclusion. A regular and moderate physical exercise program throughout pregnancy is not a risk to maternal and fetal well-being, and it helps to control excessive weight gain. (Am J Health Promot 2014;29[l]:2-8.) Key Words: Physical Exercise, Pregnancy Outcomes, Maternal, Weight Gain, Prevention Research. Manuscript format: research; Research purpose: intervention testing; Study design: randomized trial; Outcome measure: behavioral; Setting: health care; Health focus: physical activity; Strategy: behavior change, culture change; Target population age: adults; Target population circumstances: education
Ruben Barakat, PhD; Maria Perales; Javier Coteron, PhD; and Ignacio Refoyo, PhD, are on the faculty of Physical Activity and Sport Sciences at the Technical University o f Madrid, Spain. Mariano Bacchi is on the faculty of Physical Activity and Sport at the University of Flores, Buenos Aires, Argentina. Send re p rin t requests to R uben B arakat, PhD, Physical Activity a n d S p o rt Sciences, Technical U niversity o f M adrid, M artin F ierro 7, 28040 M adrid, Spain; barakatruben@ gm ail.com . This manuscript was submitted January 31, 2013; revisions were requested March 26, April 16, and April 25, 2013; the manuscript was accepted fo r publication May 16, 2013. Copyright © 2014 by American Journal of Health Promotion, Inc. 0890-1171/14/$ 5.00 4- 0 DOI: 10.4278/ajhp. 130131-QUAN-56
2
American Journal of Health Promotion
PURPOSE Pregnancy is a unique process in which nearly all of the body’s control systems are modified to maintain both maternal and fetal homeostasis.1 With physical exercise (PE) becoming an integral part of many women’s lives, the question remains as to whether this exercise has any adverse effects on pregnancy outcomes.23 In theory, the addition of PE throughout pregnancy may represent a significant challenge to both the maternal and fetal well being because the dual stresses of pregnancy and exercise may create conflicting physiological demands and thus adversely affect pregnancy out comes.4 The effects of exercise during preg nancy have been studied extensively. A dearth of well-controlled randomized studies has led to conflicting evidence as to the impact of exercise on mater nal and fetal parameters. There is a lack of consensus regarding the po tential long-term risks or benefits for the offspring of exercising mothers.5 Relative to maternal outcomes, tra ditionally preterm delivery (birth 6 MET (>21 mL 0 2/k g /m in ) 34 is p ru d en t because the definition of m oderate and vigorous should be based on each individual’s own aerobic capacity. Thus, basing exercise intensity on percentage of h eart rate and the Borg Rating of Perceived Exertion Scale (Borg’s RPE) is best when prescribing exercise in tensity in all individuals, including p reg n an t women. 35 Aerobic exercise in which large muscle groups are used, including walking, stationary cycling, aquatic exercise, or low-impact aerobics, is recom m ended for low-risk pregnant w om en.36 Many studies have shown, however, that there seems to be a discrepancy between these recom m en dations and what women actually do.37,38 T he aim of the present study was to exam ine the influence of a program of m oderate physical exercise throughout pregnancy on m aternal and fetal pa ram eters. We hypothesize th at physical exercise during pregnancy would not be associated with altered pregnancy outcomes.
METHODS Design T he p resent study was a random ized controlled trial (RCT, NCT 01696201).
Sample Subjects were 282 pregnant women living in Madrid, Spain, who were approached and inform ed of the study and inclusion criteria at their first prenatal visit by health care providers (midwives, obstetricians, and family doctors) at 6 to 7 weeks of pregnancy. Pregnant women who underw ent their first ultrasound exam ination in Hospi tal Universitario de Fuenlabrada at 10
to 12 weeks of pregnancy were offered the opportunity to participate follow ing a random ization process. A total o f 251 participants who agreed to participate were random ly allocated between two groups: 137 to the exercise group (EG) and 114 to the control group (CG). All o f the patients had uncom plicated and singleton ges tations, and their m ean age was 31.54 ± 3.86 years. W ritten inform ed consent was ob tained from each participant. The study was approved by the Research Ethics Com m ittee of Hospital Univer sitario de Fuenlabrada (Madrid, Spain) and was conducted according to the ethical guidelines o f the Declaration of Helsinki, which was last m odified in 2008. W omen presenting any type of ab solute obstetrical contraindication to exercise as suggested by American College of Obstetricians and Gynecol ogists (ACOG)31 were excluded (see below). O ther exclusion criteria were as follows: n o t planning to give birth in the obstetrics departm ent of the study hospital, n o t receiving medical follow up throughout the pregnancy, partici pating in another physical activity program , o r having a high level of pregestational physical exercise PE (four or m ore times per w eek). Be cause participating in another struc tured exercise program was an exclusion criterion, this was verified in EG at the beginning o f the study. Women in the CG confirm ed (via telephone interview) that they did not participate in a structured exercise program th roughout th eir pregnan cies. ACOG absolute obstetrical contrain dications for exercise are as follows: • Hemodynamically significant heart disease • Restrictive lung disease • Incom petent cervix • Multiple gestation • R uptured m em branes • P re e c a lm p sia /p re g n a n c y -in d u c e d hypertension For allocation of the participants, a com puter-generated list of random num bers was used. T hree different authors were responsible for carrying out the random ization process, which consisted of a sequence generation,
September/October 2014, Vol. 29, No. 1
3
allocation concealm ent, and im ple m entation. Sample Size To detect a difference in percentage o f women with a preterm delivery of 15%, with a two-sided 5% significance level and a power of 80%, the m ini m um nu m b er of 88 p reg n an t per group was necessary, given an antici pated d ro p o u t rate of 15%.39 Intervention The women who were random ly assigned to the exercise group were invited to participate in a supervised physical conditioning program that included three 55- to 60-minute ses sions p er week that began between 9 and 13 weeks o f gestation and contin ued until the end o f the third trim ester (weeks 39-40). Every session started with 5 m inutes o f walking and static stretching of most muscle groups to warm up. This warm up was followed by toning and jo in t m obilization exercises, aerobic dance, and specific exercises that targeted the m ajor muscle groups in the legs, buttocks, and abdom en to stabilize the lower back (30 m inutes); balancing exercises were also included (10 m in utes). Every session concluded with pelvic floor muscle training (10 m in utes) and a cool-down period (5 m inutes). Exercises that involved the Valsalva maneuver, extrem e stretching, jo in t overextension, ballistic move ments, and ju m p in g were specifically avoided. Furtherm ore, the exercises were perform ed in the supine position for no longer than 2 minutes. Light- to m oderate-intensity aerobic activity was prescribed, with the goal of achieving a 55% to 60% maximal heart rate. To allow the participants to identify the intensity required for the aerobic exercise, the h eart rate was shown on a poster after being calcu lated individually for each woman based on the trimester, physical condi tion, and age using the Karvonen form ula.40 T he intensity was also ad ju sted based on the Borg Scale rat ings,41 which m easured the m aternal rate o f perceived exertion. According to the National Board o f H ealth in Denm ark, p reg n an t women should engage in exercise according to Borg Scale level 12 to 13 (corresponding to m oderate/som ew hat hard exercise).44
4
American Journal of Health Promotion
All of the subjects wore a heart rate (HR) m onitor (Accurex Plus, Polar Electro OY, Kempele, Finland) during the training sessions to ensure that the exercise intensity was light to m oder ate. To maximize patient safety and adherence to the training program and its efficacy, all o f the sessions were supervised by a qualified fitness spe cialist (working with groups o f 10-12 subjects), with the assistance of an obstetrician, and were accom panied by music; the exercises were perform ed at the University Hospital of Fuenlabrada in a spacious, well-lit room u n d er favorable environm ental conditions (altitude 600 m, tem perature 19-21°C, hum idity 50-60% ). An adequate intake of calories and nutrients was ensured for each participant before the start of the exercise session. Women in the CG did not exercise during this period; they received the usual inform ation provided by their midwives o r health care professionals. Measures T he following characteristics and pregnancy outcom e were considered: m aternal age, body mass index (BMI), sm oking habits, parity, gestational age, m aternal weight gain (kg) and “ma ternal weight gain according to Insti tute o f Medicine (IOM) recom m endation,”43 preterm delivery, type of delivery, blood pressure, birth size, head circum ference, birth weight, and Apgar score. All data were collect ed in the medical report that pregnant women generated by their usual visits with health care providers (midwives, obstetricians, and family doctors) dur ing pregnancy. Analysis S tudent’s unpaired f-test was used to exam ine the differences in the de scriptive characteristics between the intervention and control groups and to know the effect o f the exercise pro gram on pregnancy outcom e (gesta tional age, m aternal weight gain, blood pressure, birth size and weight, head circum ference, Apgar scores and pH of umbilical cord). T he results are pre sented as the means ± standard deviation (SD). For the evaluation of delivery type, m aternal weight gain according to recom m endations and o ther m aternal
characteristics (e.g., parity, smoking status, educational level, prepregnancy BMI), y2 tests were used; p values of
