Obesity during pregnancy is linked to many negative health effects for mothers and
offspring. The majority of interventions with obese pregnant women based on
physical activity have had limited success suggesting alternative approaches are
needed. Sedentary behaviour is defined as waking activities that expend very low
energy, 1.5 metabolic equivalents or below, while reclining, lying or sitting.
Spending too much time sedentary has been identified as a risk factor for health,
regardless of physical activity levels. We hypothesised that targeting sedentary
behaviour may be a suitable alternative to reduce health risks during gestation
among pregnant women who are morbidly obese (defined as body mass index,
Aim and objectives
The aim was to explore sedentary behaviour among obese pregnant women and to
propose an intervention to reduce the time obese pregnant women spend sedentary,
through an active sitting exercise intervention.
To conduct a systematic review of the literature to determine the proportion of time
spent in sedentary behaviour among pregnant women, and the association of
sedentary behaviour with pregnancy outcomes in mothers and offspring.
To estimate total energy expenditure, and energy expended in sedentary activities
in morbidly obese and lean pregnant women.
To assess the feasibility of an active sitting exercise intervention for morbidly obese
pregnant women, designed using a patient involvement in research method.
A systematic review of the literature reporting sedentary behaviour during
pregnancy and its effects on pregnancy outcomes was conducted. Twenty six
publications were included in the systematic review up until October 2015, and a
further 18 were identified in the update completed in April 2018. Pregnant women
spent at least 50% of their time in sedentary activities. Associations between
increased time sedentary and higher risk of macrosomia, higher risk of pre-eclampsia,
higher risk of developing gestational diabetes mellitus, and larger new-born
abdominal circumference were observed, as the main findings. Most of included
studies scored an intermediate quality, only two of the 44 studies scored a good
A cross-sectional study was conducted, using the Pregnancy Physical Activity
Questionnaire (PPAQ), and the Actical accelerometer, to assess energy expenditure,
and energy expended in sedentary behaviour. Based on the PPAQ, women who were
morbidly obese expended significantly more energy per day, as total expenditure,
than lean pregnant women, which was confirmed by the Actical. During sedentary
behaviour lean pregnant women expended significantly less energy than morbidly
obese pregnant women, based on the PPAQ. No differences were observed between
lean and morbidly obese pregnant women in the proportion of time spent in
sedentary activities, nor in time sedentary.
Exercise Intervention Design
A patient involvement in research approach was used to design an active sitting
exercise intervention for morbidly obese pregnant women. Twenty three women
took part in the design of the intervention, enabling design of a final protocol
including six exercises, to be performed in two sets of 10 repetitions.
Active sitting exercise intervention
An intervention based on active sitting exercises for morbidly obese pregnant women
to reduce sedentary time was conducted to assess the feasibility.
Thirty morbidly obese pregnant women were recruited of whom 20% completed the
exercise intervention. The main reason not to complete the intervention was lack of
A better understanding of sedentary behaviour is needed for the design of effective
interventions to help to reduce the adverse effects of morbid obesity on pregnancy,
especially as prevalence is growing. More time spent in light intensity activities
rather than in sedentary behaviour may play a role as contributing to reduce those
risks associated with obesity during pregnancy, and to reduce time spent sedentary.
Participants have shown real interest in helping to design an effective exercise
intervention. Involving and empowering participants in how to take care of
themselves as part of the intervention helps to increase their commitment. Giving
participants the tools to take care of their own health and their babies’ should be
considered as part of the intervention with very obese pregnant women. Providing
the information in how and why exercise might help, and basing the intervention in
giving participants easy and realistic tasks that they could do on their own and
around their own environment, will help to increase their commitment. This appears
to be a feasible and effective strategy.||en