Objective
We have studied the effect of moderate physical activity that is performed by healthy women during their entire pregnancy on their perception of health status.
Study Design
Eighty sedentary women were assigned randomly to either an exercise group (n = 40) or a control group (n = 40). Maternal perception of health status and several pregnancy outcomes were recorded.
Results
Significant differences ( P = .03) were found between study groups in the percentage of women who perceived their health status as “very good”; the values that corresponded to the exercise group (n = 18; 54.5%) were better than those of the control group (n = 9; 27.3%). In addition, the women of the exercise group gained less weight (11,885 ± 3146 g) than those of the control group (13,903 ± 2113; P = .03).
Conclusion
A moderate physical activity program that is performed over the first, second, and third trimester of pregnancy improves the maternal perception of health status.
Physical exercise has gained increasing popularity among women of fertile age; many women ask for medical advice on whether they can continue to exercise throughout their pregnancy. The greater the number of pregnant women who want to participate in sports activities, the more important becomes the question about influence of exercise on mother and fetus.
Historically, women have received various advice regarding a better pregnancy and labor. These were recommendations from different groups of professionals, religious leaders, philosophers, and doctors. However, when the physical and physiologic mechanisms and processes of pregnancy started to be understood, the advice to women regarding the type of the appropriate physical exercise during pregnancy became more precise. Despite the scientific findings, some questions still exist among the researchers regarding the influence of physical exercise on several aspects of pregnant women (ie, psychologic factors). A few studies have focused on the psychologic benefits on exercise during pregnancy.
Pregnancy is a unique human process in which all the body control systems are modified to maintain maternal and fetal homeostasis. One of the most important changes during pregnancy is the metabolism of the mother, which results in a normal weight gain during pregnancy of approximately 9-11 kg. Any additional increase in the maternal weight is an energy reserve so that the mother can later feed her baby, but it also is a risk for maternal overweight, obesity, and complications to maternal health status. Obese women have increased possibilities of the development of future pelvic floor problems. This fact, combined with the increased frequency of complications during labor that are caused by obesity, puts these women in a group at special risk of poor quality of life. It should be noted here that pelvic floor problems (urinary and fecal incontinence, hyperactive bladder, pain during sexual relations, and pelvic prolapse) still remain a taboo subject. In many cases, these problems are thought erroneously to be the inherent consequence of having gone through labor. The reason for this is more cultural than scientific and seriously affects maternal perception of health status.
Regular participation in exercise programs has been associated with primary and secondary prevention of numerous physical health problems. There is also strong evidence that moderate exercise results in a more positive self-concept, improved mental well-being, an enhanced sense of well-being, a higher quality of life, and an improved mood. When a pregnant woman exercises, her improved muscular strength may be beneficial especially in preventing back pain, may help in feeling agile and nimble, and may facilitate the added weight and the changing center of gravity. Also, recent studies in this area have shown that physical exercise during pregnancy plays an important role in the prevention of obesity and excessive weight gain and in control of the weight of women who are already obese; this can be achieved without any maternal-fetal risks, as far as pregnancy outcomes are concerned.
The traditional recommendations regarding physical activity during pregnancy have been based more on cultural and social matters rather than scientific evidence. Even nowadays, doubts exist among both obstetricians and sport scientists regarding the type, the intensity, the duration, and the frequency of physical exercise during pregnancy and its influence on the maternal psychologic aspects. A more important aspect is the maternal perception of health status. Adequate research in this area of science is therefore necessary. This becomes even more obvious when one takes into account the fact that everyday more women want to continue to exercise in some form, during their pregnancy.
The aim of this study was to investigate the influence of a program of moderate physical exercise during the entire pregnancy on maternal perception of health status and other pregnancy outcomes.
Materials and Methods
The present study was a randomized, controlled training trial. We contacted a total of 360 Spanish (white) women in a low-to-medium socioeconomic class (the contact was made by the obstetrician during the first prenatal visit). From the initial number of pregnant women, finally 67 women were studied ( Figure ). The research protocol was reviewed and approved by our Ethics Committee and followed the ethical guidelines of the Declaration of Helsinki, which was last modified in 2008. The research was carried out in collaboration with the Obstetric Hospital Department (Hospital de Fuenlabrada, Madrid, Spain). All participants were informed about the aim and study protocol, and written informed consent was provided by all women. All exercises were carried out under the supervision of an obstetrician.
Subjects
We randomly assigned (by use of a random number table) 80 healthy pregnant women (age, 23-38 years) to either an exercise group (EG; n = 40) or a control group (CG; n = 40). Women not planning to give birth in the same obstetrics hospital department (Hospital de Fuenlabrada, Madrid, Spain) and not receiving medical follow-up evaluations throughout the entire pregnancy period were not included in the study. Both groups included subjects with similar prepregnancy level of physical activity or type of recreational exercise. All the women were healthy and had uncomplicated and singleton pregnancies.
The exclusion criteria were any type of absolute obstetric contraindication to aerobic exercise during pregnancy, which included other contraindications that the authors considered to have a relevant influence on maternal perception of health: hemodynamically significant heart disease, restrictive lung disease, incompetent cervix/cerclage, multiple gestation, risk of premature labor, preeclampsia/pregnancy induced hypertension, thrombophlebitis, recent pulmonary embolism (last 5 years), acquired infectious disease, retarded interuterine development, serious blood disease, and/or absence of prenatal control.
Exercise program
The physical conditioning program included a total of 35- to 45-minute weekly sessions 3 days each week (Monday, Wednesday, Friday) from the start of the pregnancy (weeks 6-9) to the end of the third trimester (weeks 38-39). Thus, an average of 85 training sessions was planned originally for each participant in the event of no preterm delivery. All subjects used a heart rate monitor (Accurex Plus; Polar Electro OY, Oulu, Finland) during the training sessions to ensure that exercise intensity was light-to-moderate (that is, their heart rate was consistently under 70% of their age-predicted maximum heart rate value [220 minus age]). Each session included a 25-minute core session that was preceded and followed by a gradual warm-up and cool-down period, respectively (both of 7-8 minute duration and consisting of walking and light, static stretching [avoiding muscle pain] of most muscle groups [upper and lower limbs, neck and trunk muscles]). The cool-down period also included relaxation and pelvic floor exercises. The core session included the following toning and very light resistance exercises: toning and joint mobilization exercises that included shoulder shrugs and rotations, arm elevations, leg lateral elevations, pelvic tilts, and rocks. Resistance exercises were performed through the full range of motion that normally is associated with correct technique for each exercise and engaged the major muscle groups (pectoral, dorsal, shoulder, upper and lower limb muscles). They included 1 set (10-12 repetitions of each) of abdominal curls and the following exercises with barbells (3 kg/exercise) or low-to-medium resistance bands (Therabands; The Hygenic Corporation, Akron, OH): biceps curls, arm extensions, arm side lifts, shoulder elevations, bench press, seated lateral row, lateral leg elevations, leg circles, knee extensions, knee (hamstring) curls, ankle flexion, and extensions. We specifically avoided any exercises that involved extreme stretching and joint overextension, ballistic movements or jumps. Any type of exercises on the back were performed for no more than 2 minutes.
We used exercises that covered the major muscle groups of arms and abdomen to promote good posture and prevent low back pain and, in the third trimester, to strengthen the muscles of labor and pelvic floor. We also included in the program 1 session per week of aerobic dance.
To maximize safety, adherence to the training program, and its efficacy, all sessions were supervised by a qualified fitness specialist (working with groups of 10–12 subjects) and with the assistance of an obstetrician, were accompanied by music, and were performed in the hospital, in a spacious, well-lit room under favorable environmental conditions (altitude 600 m; temperature, 19-21°C; humidity, 50–60%).
The following general considerations were given to the exercise program: All the activity was of aerobic type, and an adequate intake of calories and nutrients was assured before the start of the exercise program. As a general rule and to avoid potential risks, the following activities were avoided: activities that included Valsalva’s mechanism; high room temperatures or humid environments, with the aim to avoid chances of hyperthermia (body temperature, >38°C); ballistics movements; and positions of extreme muscular tension.
Variables of the study
The following maternal characteristics have been taken into account: age, body mass index, smoking habits, alcohol intake, occupational activity, time standing per day, time of domestic task, educational level, and parity.
The variables that are related to health perception and urinary incontinences were perception of health status level and frequency to pregnant women lose urine.
The SF-36 King’s Health Questionnaire has been used. This test is a multipurpose, short-form health survey with only 36 questions and yields an 8-scale profile of functional health and well-being scores, psychometrically based physical and mental health summary measures, and a preference-based health utility index.
The CIQ-SF Incontinence classification of the International Continence Society has also been used. This test measures the subjective grade of urinary incontinence (regarding the patient) and its impact on quality of life.
Because the aim of the study was to observe the influence of exercise on the process of pregnancy and delivery, the questionnaires were given to the subjects after delivery. The study assumed that all participating subjects had started their pregnancy with the same (good) level of perception of their health status, which was confirmed during their first prenatal visit. Regarding incontinence problems, women who experienced such problems before pregnancy were excluded from the study.
The pregnancy outcomes that were considered were maternal weight gain, gestational age, type of delivery, delivery lacerations, blood pressure, 1-hour glucose tolerance, birthweight, and Apgar score.
Data analysis
Our data were analyzed with the use of the Student t test for independent samples ( Tables 1-3 ).
