Table 2 Multivariable associations between sociodemographic, living environment, maternal health and medical history and pregnancy history variables and stillbirth

Demographics

Mothers age

 < 20

1.11 (0.59 to 2.06)

0.747

0.95 (0.50 to 1.81)

0.873

0.95 (0.49 to 1.83)

0.878

1.05 (0.55 to 2.03)

0.878

20–24

Reference category

25–30

1.65 (1.08 to 2.51)

0.019

1.59 (1.04 to 2.44)

0.034

1.65 (1.07 to 2.55)

0.024

1.32 (0.82 to 2.11)

0.252

31–35

1.60 (0.96 to 2.67)

0.072

1.72 (1.02 to 2.91)

0.041

1.76 (1.04 to 3.00)

0.037

1.21 (0.65 to 2.27)

0.550

36–40

1.47 (0.86 to 2.53)

0.161

1.49 (0.85 to 2.60)

0.160

1.41 (0.80 to 2.50)

0.237

0.93 (0.48 to 1.83)

0.839

 > 40

1.97 (0.91 to 4.26)

0.085

2.25 (1.01 to 5.00)

0.047

2.20 (0.97 to 4.97)

0.058

1.26 (0.51 to 3.12)

0.614

Household monthly income (NGN)

 < 45,000

Reference category

≥ 45,000

1.07 (0.78 to 1.47)

0.686

0.96 (0.69 to 1.33)

0.807

0.91 (0.64 to 1.28)

0.574

0.92 (0.65 to 1.31)

0.658

Employment status

Employed

Reference category

Unemployed

1.19 (0.87 to 1.62)

0.267

1.18 (0.86 to 1.62)

0.307

1.04 (0.75 to 1.46)

0.804

1.13 (0.81 to 1.59)

0.470

Highest level of education

Secondary school or above

Reference category

None or primary school

3.04 ( 2.21 to 4.20)

 < 0.001

2.23 (1.50 to 3.02)

 < 0.001

2.12 (1.48 to 3.01)

 < 0.001

1.94 (1.35 to 2.79)

 < 0.001

Living environment

Distance travelled to hospital

 < 10 km

Reference category

10-30 km

1.48 (1.07 to 2.04)

0.019

1.50 (1.08 to 2.10)

0.016

1.52 (1.08 to 2.12)

0.015

31-50 km

3.56 (1.96 to 6.45)

 < 0.001

3.82 (2.06 to 7.11)

 < 0.001

3.64 (1.93 to 6.85)

 < 0.001

51-100 km

3.85 (1.48 to 10.03)

0.006

3.23 (1.19 to 8.72)

0.021

3.39 (1.25 to 9.21)

0.017

 > 100 km

4.57 (1.41 to 14.87)

0.012

4.14 (1.25 to 13.65)

0.020

4.44 (1.31 to 15.05)

0.017

Type of residence

Apartment or house

Reference category

Shack or other

1.50 (1.07 to 2.10)

0.018

1.55 (1.09 to 2.20)

0.014

1.50 (1.05 to 2.13)

0.026

Primary household water source

Municipal network

Reference category

Not municipal network

1.43 (0.90 to 2.26)

0.130

1.46 (0.91 to 2.32)

0.113

1.47 (0.92 to 2.35)

0.110

Household toilet facilities

Toilet with flush

Reference category

Pit latrine or other

1.57 (1.11 to 2.21)

0.010

1.49 (1.05 to 2.11)

0.027

1.41 (0.99 to 2.02)

0.055

Health and medical history

Self-perceived nutritional status

Healthy weight

Reference category

Overweight

0.82 (0.42 to 1.63)

0.579

0.78 (0.39 to 1.57)

0.488

Underweight

1.35 (0.77 to 2.38)

0.297

1.46 (0.83 to 2.59)

0.189

Medication

Antibiotics

1.56 (0.91 to 2.68)

0.107

1.54 (0.89 to 2.66)

0.122

Anti-inflammatories

0.78 (0.06 to 9.74)

0.850

1.05 (0.09 to 12.77)

0.968

Pain relief

0.58 (0.39 to 0.85)

0.005

0.59 (0.40 to 0.87)

0.008

Traditional

1.43 (0.92 to 2.24)

0.113

1.40 (0.89 to 2.21)

0.142

Antiretroviral therapy (ART)

1.57 (0.15 to 16.47)

0.708

1.64 (0.15 to 18.13)

0.688

Other

0.99 (0.50 to 1.96)

0.979

1.07 (0.54 to 2.12)

0.853

Supplements

Vitamins

1.02 (0.57 to 1.82)

0.941

1.01 (0.57 to 1.81)

0.969

Folic acid / iron / haemoglobin

0.94 (0.65 to 1.36)

0.748

0.93 (0.64 to 1.34)

0.685

Health conditions

Malaria

0.78 (0.54 to 1.15)

0.212

0.76 (0.52 to 1.12)

0.169

Fever / infection

2.48 (1.12 to 5.49)

0.025

2.53 (1.12 to 5.70)

0.025

Hypertension

1.95 (1.24 to 3.09)

0.004

1.95 (1.23 to 3.10)

0.005

Pregnancy History

Pregnancy History

Grand multiparity ≥ 5 pregnancies

1.43 (0.91 to 2.23)

0.119

Previous stillbirth(s)

2.37 (1.64 to 3.42)

 < 0.001