| Primary research only |
Systematic reviews and secondary data |
| Qualitative studies (or mixed-methods studies if qualitative results reported separately) |
Quantitative data |
| Nigerian populations |
Non-Nigerian population |
| Women of child-bearing age |
|
| Focus on peripartum period |
Focus on antepartum or postpartum periods |
| Peer-reviewed articles or grey literature published in English |
Non-English papers |
| No restriction by publication type |
|