Table 3 Risk factors for postpartum mortality

General maternal population

 Mode of delivery

Harrison et al., 2017 [21]

2.42 (1.95–3.01)

CS^a

VD^b (includes both spontaneous and assisted vaginal deliveries)

Kanyighe et al., 2008 [13]

7.38 (2.08–26.07)

CS

CS not conducted

Oladapo et al., 2007 [23]

2.01 (0.03–38.83)

Elective CS

Non-operative VD following spontaneous onset of labour

 Parity

Kanyighe et al., 2008 [13]

3.34 (1.46–7.66);

1.37 (0.50–3.72)

Nulliparous mothers; high parity (> 3 previous births)

Low parity (1–3 previous births)

 Birthweight

Kanyighe et al., 2008 [13]

83.23 (10.24–676.2);

3.51 (1.85–6.63)

Very low birth weight (< 1.5 kg); low birth weight (1.5 kg-2.5 kg)

Normal birth weight (> 2.5 kg)

 Apgar score

Kanyighe et al., 2008 [13]

1.67 (0.31–8.94)

Low score (1–5)

Normal score (6–10)

ICU admissions population

 Age

Igbaruma et al., 2016 [24]

0.44 (0.18–1.11)

Mothers < 20 & ≥ 35 years

Mothers aged 20–34 years

 Marital status

Igbaruma et al., 2016 [24]

0.73 (0.26–7.02)

Single

Married

 Referral status

Igbaruma et al., 2016 [24]

0.98 (0.40–2.40)

Not referred

Referred

 Education

Igbaruma et al., 2016 [24]

1.39 (0.49–3.91)

Secondary maternal education or less

Post-secondary maternal education

 Place of delivery

Igbaruma et al., 2016 [24]

0.44 (0.10–1.97);

0.30 (0.04–2.20)

Primary health facility; home/informal maternal setting

Delivery in a secondary/tertiary facility

Postpartum hemorrhage population

 Severity of shock upon admission

Ojengbede et al., 2011 [25]

6.84 (1.55–30.19)

MAP^e < 60

MAP ≥ 60

 Parity

Ojengbede et al., 2011 [25]

0.91 (0.40–2.06)

High parity (5 or more)

Low parity (0–4)