# Table 2 Univariable and multivariable odds ratios showing the association between foetal movement variables and late stillbirth

Case, N = 851

Control, N = 2257

Univariable OR (95% CI)

Multivariable OR** (95% CI)

Strength of movements in the last 2 weeks: 4 categories

Increased

124

1061

0.21 (0.17, 0.26)

0.18 (0.14, 0.23)

Decreased

195

179

1.94 (1.53, 2.45)

1.82 (1.37, 2.42)

No change

446

793

1

1

Unsure

79

118

1.19 (0.88, 1.62)

0.96 (0.67, 1.38)

Frequency of movements in the last 2 weeks: 4 categories

Increased

83

648

0.33 (0.25, 0.42)

0.29 (0.21, 0.38)

Decreased

265

268

2.52 (2.06, 3.09)

2.48 (1.94, 3.16)

No change

443

1131

1

1

Unsure

53

114

1.19 (0.84, 1.67)

0.93 (0.62, 1.39)

How often was a baby more vigorous than usual in the last 2 weeks: 3 categories

Once

133

124

2.25 (1.72, 2.95)

2.30 (1.68, 3.16)

2.86 (2.01, 4.07)

More than once

165

903

0.38 (0.31, 0.47)

0.41 (0.32, 0.52)

0.67 (0.52, 0.87)

Never

430

901

1

1

1

During the last 2 weeks/this pregnancy did you feel your baby having hiccups?

Yes

355

1359

0.40 (0.34, 0.48)

0.42 (0.34, 0.53)

0.45 (0.36, 0.58)

No

329

509

1

1

1

Unsure

51

100

0.79 (0.55, 1.14)

0.94 (0.61, 1.44)

0.93 (0.58, 1.49)

During the last 2 weeks, did you feel uterine contractions (tightenings/pre-labour contractions/Braxton-Hicks contractions/false labour)?

Yes

253

653

1.04 (0.86, 1.25)

0.97 (0.77, 1.22)

No

352

941

1

1

Combination of strength and frequency changes in the last 2 weeks (prioritised variable)

Missing = 6

Missing = 95

Increased strength

124

1061

0.22 (0.17, 0.27)

0.19 (0.15, 0.24)

0.20 (0.15, 0.27)

Increased frequency but not strength

25

97

0.47 (0.30, 0.75)

0.44 (0.26, 0.74)

0.50 (0.29, 0.88)

Decreased frequency

249

196

2.34 (1.87, 2.92)

2.36 (1.79, 3.10)

2.33 (1.73, 3.14)

Unsure of strength or frequency

57

91

1.15 (0.81, 1.64)

1.01 (0.67, 1.52)

0.85 (0.53, 1.38)

The same strength or frequency

390

717

1

1

1

1. Adjusted and multivariable models adjusted for maternal age (6 groups), maternal BMI (continuous), maternal ethnicity (7 groups), parity (4 groups), maternal education (5 groups), marital status (yes/no), maternal pre-existing HTN, DM (yes/no), smoking status (yes/no), recreation drug use (yes/no), customised centile(6 groups), most recent going-to-sleep position (7 groups) and a stratification statement for study and site
2. *Adjusted OR is a multivariable model with each individual foetal movement variable added alone
3. **Multivariable model is a multivariable model including all foetal movement variables included in that column in the model. The individual frequency and strength variables are not included as they are accounted for in the combined variable, and uterine contractions were not included due to the lack of significance in the univariable analysis