Relationship between physical activity measured by accelerometer and by

questionnaire in pregnancy

Cath McParlinLouise Hayes

Benefits of PA in pregnancy

Potential to:• Maintain energy balance• Reduce excessive gestational weight gain• Improve pregnancy outcomes

Obese women• Poor glycaemic control, insulin resistance, metabolic

syndrome

Observational data• Predominantly self-report, contradictory/conflicting• Potential association PA and GDM

Guidelines in pregnancy

• Importance of healthy eating and appropriate exercise for all women, esp. if BMI>30

• Dispel myths• Recommend 30 mins

moderate activity per day

• Importance of not being sedentary

Intervention studies

• Various approaches• Goal setting, motivational interviewing, behaviour

change techniques

Predominantly ineffective in achieving outcomes

Often PA/behaviour change not measured

? can PA be increased

? would an increase result in improved outcomes

Measuring PA in pregnancyvalidity/reliability/acceptability

Accelerometry• Position• Cut points• Compliance• Not waterproof• Upper body• EE in pregnancy

Questionnaire• PPAQ correlations

(light -0.08 – 0.22

mod. 0.20 – 0.49)• Over estimate, multi tasking• Focus on LTPA

Advantage:

Recreational activities

EE in different domains

Measuring Activity in Pregnancy Study (MAPS)

• Pilot feasibility study• Pregnant women, (n=68, BMI>25)• PA measured at 12-14 weeks gestation for 7

days

1. Actigraph accelerometer

2. Recent Physical Activity Questionnaire

Activity (min/day) Median (IQR) Spearman’s ρ

Accelerometer

Sedentary (<100 cpm) 631 (574, 673)

Light (100-1951 cpm) 125 (97, 153)

MVPA (>1952 cpm) 35 (28, 51)

All activity 165 (127, 192)

RPAQ

Sedentary (<1.5 MET) 1197 (1058, 1318) 0.30*

Light (1.5-2.9 MET) 94 (60, 231) 0.41**

MVPA (>3.0 MET) 81 (35, 169) 0.06

All activity 243 (122, 382) 0.53**

Correlation between RPAQ and accelerometer

MAPS (n=55)

**p<0.01; *p<0.05

Bell R et al 2013 EGOG:170;90

Activity (min/day) Median (IQR) Spearman’s ρ

Accelerometer

Sedentary (<100 cpm) 1167 (1111, 1218)

Light (100-1951 cpm) 175 (140, 222) 

MVPA (>1952 cpm) 39 (25, 52)

All activity 216 (168, 265) 

RPAQ

Sedentary (<1.5 MET) 1007 (878,1140) 0.42**

Light (1.5-2.9 MET) 372 (233, 473)  0.05

MVPA (>3.0 MET) 26 (12, 56) 0.25**

All activity 424 (283, 532) 0.15

Correlation between RPAQ and accelerometer

UPBEAT pilot study (n=102)

**p<0.01

Time in different PA intensities by RPAQ tertile

UPBEAT pilot study (n=102)

Tertile 1 Tertile 2 Tertile 3

Sedentary (<100 cpm): min/d

1165 (110) 1168 (109) 1180 (99)

% weartime 72 (11) 73 (10) 75 (12)

Light (100-1951 cpm): min/d 184 (88) 171 (80) 172 (89)

% weartime 23 (8) 21 (9) 20 (11)

MVPA (>1952 cpm): min/d 40 (27) 41 (26) 38 (29)

% weartime 4.5 (3) 4.8 (3) 4.7 (4)

All activity: min/d 220 (101) 215 (95) 210 (96)

Counts per minute 275 (129) 288 (172) 269 (149)Figures are median (IQR)

Proportion meeting PA guidelines

UPBEAT pilot study (n=102)

0

10

20

30

40

50

60

70

Actigraph - 30 min MVPA Actigraph - 30 min MVPA ( bouts)

RPAQ - 30 min MVPA RPAQ - 500 MET/min/d

Conclusions

• Poor agreement between accelerometer and RPAQ assessed PA in pregnant women

• Choice of method affects estimates of pregnant women achieving guidelines

• Implications for understanding of relationship between PA during pregnancy and outcomes

Why does it matter?

• Need to (try to) quantify the dose-response relationship between PA and pregnancy outcomes

• Want to determine proportion of women meeting guidelines to guide public health activity and to assess effectiveness of interventions

Acknowledgements

Participants in MAPS and UPBEATLucilla Poston, Ruth Bell, Steve Robson and UPBEAT teamFunders – NIHR Programme Grant: RP-0407-10452