Does exercise training during pregnancy affect gestational age? A randomised controlled trial

Abstract

Background: Some controversy exists over the possibility that exercise during pregnancy might increase the risk of preterm delivery. Objective: This study aimed to determine the possible cause-effect relationship between regular exercise performed during the second and third trimesters of pregnancy by previously sedentary, healthy gravidae and gestational age at the moment of delivery. Methods: Caucasian (Spanish) women with singleton gestation were assigned to either a training (n = 72) or a control (n = 70) group. The supervised training programme focused mainly on very light resistance and toning exercises and included ,80 sessions (three times/ week, 35 min/session from weeks 12-13 to weeks 38-39 of pregnancy). Results: No significant differences were found (p.0.05) between the groups in those maternal characteristics (age, smoking habits, number of hours standing or prior parity history) that could potentially influence gestational age. The mean gestational age did not differ (p = 0.745) between the training (39 weeks,3 days (SD 1 day)) and the control group (39 weeks,4 days (SD 1 day)). Conclusions: Previously sedentary, healthy gravidae with singleton gestation can safely engage in moderate, supervised exercise programmes until the end of gestation as this would not affect gestational age.Historically, and largely based on socio-cultural reasons more than on scientific evidence, pregnant women have been encouraged to reduce physical activity (PA) and stop working during pregnancy because of perceived increased risk of problems, e.g., such as early pregnancy loss or reduced placental circulation. 1In 1985 the American College of Obstetricians and Gynecologists (ACOG) provided conservative recommendations for exercise during pregnancy; women were told to avoid intense activities (such as jogging or cycling) for more than 15 minutes per session, and limit their heart rate to (140 beats/min.2 In recent years, however, an increasing number of women are engaging in regular exercise during pregnancy. This tendency is overall supported by the results of several publications over the last decade, reporting few negative effects of PA on the pregnancy of a healthy gravida. [4][5][6][7] More recent ACOG guidelines are in fact more proactive regarding exercise recommendations during pregnancy. 8 Obstetricians, family practitioners and nurse midwives are, however, not always prepared to provide constructive guidance for their physically active patients. One question frequently addressed and still to be clearly answered relates to the possibility that high PA levels, especially during the second part of pregnancy, might increase the risk for preterm delivery. A potential source of controversy on this issue arises from the fact that more ''active'' or energy-consuming occupational professional activities that require prolonged standing (.3 h/day) and/or carrying loads .10 kg, such as in industrial work or as cleaning staff and shopkeepers, might increase the risk of preterm births and low birth weight in compari...

Resistance exercise training during pregnancy and newborn's birth size: a randomised controlled trial

“…15 In brief, the study was a randomised controlled trial (ClinicalTrials.gov ID NCT00813657). The research protocol was reviewed and approved by the Hospital Severo Ochoa (Madrid, Spain).…”

“…We originally planned an average of about 80 training sessions for each participant in the event of no preterm delivery. Details of the exercise training protocol have been described by Barakat et al 15 In brief, each session consisted of 35-40 min of exercise divided into a light intensity (p60% maximal heart rate) warm-up period (B8 min), followed by toning and very light resistance exercises (B20 min), and finishing with a light intensity cool-down (B8 min) period.…”

Fetal heart rate responses during maternal resistance exercise: a pilot study

“…MÉTODOS: Dez gestantes (22-24 semanas, 25,2±4,4 anos, 69,8±9,5 kg, 161,6±5,2 cm) realizaram as seguintes sessões experimentais com [22][23][24]28-32 e 34-36 semanas de gestação: A Sessão 1 foi a familiarização com os equipamentos e determinação de uma repetição máxima estimada. Para as Sessões 2, 3, 4 e 5, foi determinada a FCF durante a execução do exercício de força nos equipamentos extensão de joelhos bilateral e voador, com 1 e 3 séries de 15 repetições e carga de 50% de uma repetição máxima estimada.…”

Efectos de un programa de ejercicio físico supervisado sobre la estructura cardiaca durante la gestación. Ensayo clínico aleatorizado

“…A pesar de que en los últimos años son muchos los estudios que se han ocupado de la relación entre el ejercicio físico y los resultados del embarazo 3,4,11,18 , permanecen ciertos interrogantes sobre la respuesta cardiovascular de la mujer gestante como respuesta a cargas moderadas y regulares de ejercicio físico.…”

“…En este sentido, son muchos los estudios que informan de posibles mejoras en la salud de estas gestantes a través de la práctica regular de ejercicio físico moderado durante el embarazo [3][4][5][6][7][8][9][10] .…”