Table 1 Description of included studies (arranged alphabetically)

Both, et al. (2010) [31]

UK

11759

Cohort

Pregnant women due to deliver between April 1st 1991 and December 31st 1992.

Self-reported questionnaire.

Non-objective.

Who declared being mostly sitting.

Intermediate

Chasan-Taber, et al. (2014) [40]

USA

1276

Cohort

Women of Puerto Rican or Dominican Republic heritage.

Modified version of the Pregnancy Physical Activity Questionnaire (PPAQ).

Non-objective.

Activities expending <1.5 METs.

Intermediate

Chasan-Taber, et al. (2015) [34]

USA

1240

Cohort

Women of Puerto Rico or Dominican Republic heritage.

PPAQ.

Non-objective.

The sum of the MET-h/day spent watching TV/videos or sitting/standing at home, work, or during transportation.

Intermediate

Di Fabio, et al. (2015) [8]

USA

46

Cohort

Healthy pregnant women, including women between 18 and 45 years of age and singleton pregnancy.

- 7 day record diary.

- Non-objective.

Activities expending ≤1.5 METs (independent of nighttime sleep).

Intermediate

- SenseWear® Mini armband accelerometer.

- Objective.

- ActivPAL™ Multi-sensor accelerometer.

- Non-objective.

Evenson, et al. (2010) [37]

USA

1280

Cohort

Pregnant women ≥16 years of age.

The Behavioral Risk Factor Surveillance System (BRFSS).

Non-objective.

Two questions on TV watching and computer usage outside of work hours were used as SB indicators. Women were also asked if they were ‘mostly sitting’ during their usual daily activities.

Poor

Evenson, et al. (2011) [11]

USA

359

Cross-sectional

Pregnant women ≥16 years.

ActiGraph accelerometer.

Objective.

Activities expending <100 counts per minute.

Intermediate

Gollenberg, et al. (2010) [36]

USA

1006

Cohort

Latina ethnicity, age 16–40 years old, singleton pregnancy, and no prior participation in the study.

Modified version of the Kaiser Physical Activity Survey (KPAS).

Non-objective.

Hours spent TV watching per day and frequency of sitting at work.

Intermediate

Gradmark, et al. (2011) [47]

Sweden

101

Cross-sectional

Normal weight and overweight women without diabetes were studied.

Actiheart monitor.

Objective.

Epochs with valid heart rate data and zero accelerometry counts/min.

Intermediate

Hawkins, et al. (2014 Im.) [48]

USA

260

Randomized controlled trial

Women in their first trimester of pregnancy, between 16 and 40 years old, and at high risk for GDM.

Pregnancy Physical Activity Questionnaire (PPAQ).

Non-objective.

The amount of time spent watching TV or videos, or sitting or standing at home, work, or during transportation.

Good

Hawkins, et al. (2014 PA) [10]

USA

294

Cross-sectional

Women in the 2003–2006 NHANES study cycles who self-reported currently being pregnant, were 16 year or older, and who had available data on C reactive protein, physical activity, and SB.

ActiGraph accelerometer.

Objective.

Activities expending <100 counts per minute.

Intermediate

Hayes, et al. (2014) [49]

UK

183

Randomized controlled trial

All obese (BMI ≥ 30 K/m²) pregnant women.

- Acti-Graph accelerometer.

- Objective.

- Accelerometry: any minute with ≤100 counts/min.

Good

- Recent Physical Activity Questionnaire (RPAQ).

- Non-objective.

- RPAQ, minutes spent on activities <1.5 MET.

Hegaard, et al. (2010) [32]

Denmark

4558

Cohort

Danish-speaking pregnant women.

Self-reported questionnaires.

Non-objective.

Those who chose “mostly sitting” to describe most correctly her level of leisuretime activity.

Intermediate

Hegaard, et al. (2011) [35]

Denmark

4718

Cohort

Age ≥ 18 years, Danish speaking, singleton pregnancy, and intended spontaneous vaginal delivery.

Self-administered questionnaire.

Non-objective.

Those who answered: “Reading, watching television, or pursuing some other sedentary occupation”, as the most appropriate description of her activities.

Intermediate

Hjorth, et al. (2012) [9]

Ethiopia

304

Cross-sectional

All pregnant women who attended routine visits at the antenatal care clinic.

- Actiheart (heart rate and movement device).

- Objective.

Energy expenditure ≤1.5 METs.

Intermediate

- 24 h physical activity recall.

- Non-objective.

Jiang, et al. (2012) [30]

China

862

Cohort

Pregnant women over 20 years old in a singleton pregnancy, and had no disease including gestational diabetes (GD), hypertension, heart disease, chronic renal disease, and other diseases restricting physical activity.

Pedometer.

Objective.

Less than 5000 steps per day.

Intermediate

Kamareswaran, et al. (2013) [41]

UK

10

Cohort

Type 1 diabetes, current insulin pump therapy, and a viable singleton pregnancy.

Actiheart (heart rate and movement device).

Objective.

Activities expending ≤1 MET.

Intermediate

Li & Zhao (2007) [46]

China

405

Cross-sectional

Pregnant women working in a sewing factory.

Self-reported questionnaire.

Non-Objective.

According to the job, women were assigned to the study group (persistent sedentary) or control group.

Poor

Loprinzi, et al. (2013) [44]

USA

206

Cross-sectional

All women who answered the 2003–2006 National Health and Examination Survey.

ActiGraph accelerometer.

Objective.

Activity counts between 0 and 99 counts/min.

Intermediate

Lynch, et al. (2012) [43]

USA

1355

Cohort

Women from the ambulatory obstetric practices at ≤20 weeks of gestation.

PPAQ.

Non-objective.

The amount of time spent watching TV or videos, or sitting or standing at home, work, or during transportation.

Intermediate

Oken, et al. (2006) [29]

USA

1581

Cohort

Women attending initial prenatal visit, who delivered live infants.

Modified version of the leisure time activity section of the Physical Activity Scale for the Elderly (PASE).

Non-objective.

Hours per week spent watching TV or videos.

Intermediate

Padmapriya, et al. (2015) [42]

Singapore

1171

Cohort

Pregnant women aged 18 years and above attending first trimester antenatal dating ultrasound scan clinics.

Interview questionnaire.

Non-objective.

Hours spent on sitting plus hours spent on watching TV per day.

Intermediate

Reid, et al. (2014) [39]

Northern Ireland

100

Cohort

Healthy women, ≥16 years old, with singleton pregnancies, between 26 and 37 week gestation.

Body-media SenseWear Pro3 armband.

Objective.

Activities expending ≤1 MET.

Intermediate

Rhodes, et al. (2014) [33]

Canada

157

Cohort

The cohorts were couples without children, first-time parents during the first year of their parenthood experience, and second time parents during the first year of this parenting experience between the ages of 25 and 40 years of age.

GT1M Activity Monitor (accelerometer and stepcounter).

Objective.

Activities expending 0–100 average acceleration counts/min.

Intermediate

Ruifrok, et al. (2014) [12]

Netherlands

111

Cohort

Healthy pregnant women. Trial 1: nulliparous pregnant women without BMI restrictions, able to read, write and speak Dutch, and within their first 14 weeks of pregnancy; Trial 2: overweight and obese pregnant women at risk for gestational diabetes.

ActiTrainer accelerometer (Acti-Graph).

Objective.

Activities expending <100 counts/min.

Intermediate

Van Raaij, et al. (1990) [38]

Netherlands

18

Cohort

Healthy women judged by medical histories, blood pressure, hemoglobin concentration, and urine analysis.

- Open-circuit indirect calorimetry.

- Objective.

Lying, sitting quietly or very light sitting activity, or light-to-moderate sitting activity.

Intermediate

- Physical activity diaries.

- Non-objective.

Watts, et al. (2013) [45]

Australia

81

Cross-sectional

Pregnant women regardless of their pregnancy trimester.

The Australian Women’s Activity Survey (AWAS).

Non-objective.

Frequency and duration of sitting behavior.

Poor