A new analysis led by researchers at the Leverhulme Centre for Demographic Science calls for the expansion of maternal health metrics to include stillbirths, not just live births.
The study, published in eClinicalMedicine, demonstrates that recent improvements in global stillbirth estimates make it increasingly feasible for maternal mortality metrics to move beyond including only live births, and instead use total births as the standard denominator.
The global Maternal Mortality Ratio (MMR) measures how many women die during pregnancy or up to 42 days after pregnancy from maternal causes per 100,000 live births. The MMR is used to track progress against Sustainable Development Goal (SDG) 3.1 ‒ to reduce global maternal mortality to less than 70 maternal deaths per 100,000 live births by 2030.
However, many pregnancies do not end in live birth, but instead end in stillbirth, miscarriage, or abortion. Complications associated with these pregnancy outcomes can lead to maternal death or morbidity, especially in low- and middle-income countries (LMICs) where access to safe abortion services and quality obstetric care may be limited.
While such deaths are included in the numbers of deaths (the numerator of the MMR), the pregnancy outcomes that caused them are excluded from the denominator (live births). This mismatch, the researchers argue, distorts the true picture of maternal risk. It may also reinforce the misconception that maternal deaths occur only following live births.
The researchers re-calculated maternal and pregnancy-related mortality ratios (PRMR) using more inclusive denominators: total births (live births plus stillbirths) and total pregnancies (adding miscarriages/induced abortions). The study used data from Demographic and Health Surveys (DHS) conducted between 1996 and 2023, including data from people living in 46 LMICs across Africa, Asia, Latin America and the Caribbean, and Oceania.
Key findings
- Live births accounted for 70% (Cambodia 2021) – 96% (Papua New Guinea 2017) of reported pregnancy outcomes; variation may reflect real differences or be influenced by cultural norms, legal contexts, access to care, and reporting biases;
- The reported proportion of pregnancies ending in stillbirth ranged from 0.3%–4.1%; reported miscarriage/induced abortion ranged from 2.2%–30%;
- Switching to a total birth denominator reduced the MMR and PRMR by up to 2.8% (Cote d'Ivoire, 2021);
- Using total pregnancies reduced these ratios by up to 23% (Cambodia, 2021).
Ursula Gazeley, postdoctoral researcher in reproductive demography and first author of the study, said ‘Our findings underscore the need to revisit how maternal health metrics are defined, particularly the potential inclusion of stillbirths in the denominator. With five years left in the SDG period, we urge reflection on current measurement practices. Including stillbirths could lead to more conceptually accurate estimates of maternal risk, strengthen stillbirth surveillance efforts, and help prioritise their prevention on the global health agenda.’
The authors make the case for the future inclusion of stillbirths in maternal metrics. Doing so, they argue, would not only improve accuracy but may also help incentivise further improvements in stillbirth reporting systems, especially in settings where data are weak.
These data could be used to help identify when and where stillbirths occur, and guide improvements in the quality of pregnancy care.