Causes of and factors associated with stillbirth in low- and middle-income countries: a systematic literature review

Abstract

Background: Annually, 2.6 million stillbirths occur worldwide, 98% in developing countries. It is crucial that we understand causes and contributing factors.

Methods: We conducted a systematic review of studies reporting factors associated with and cause(s) of stillbirth in low- and middle-income countries (2000-13). Narrative synthesis to compare similarities and differences between studies with similar outcome categories.

Main results: A total of 142 studies with 2.1% from low-income settings were investigated; most report on stillbirths occurring at health facility level. Definition of stillbirth varied; 10.6% of studies (mainly upper middle-income countries) used a cut-off point of ≥22 weeks of gestation and 32.4% (mainly lower income countries) used ≥28 weeks of gestation. Factors reported to be associated with stillbirth include poverty and lack of education, maternal age (>35 or <20 years), parity (1, ≥5), lack of antenatal care, prematurity, low birthweight, and previous stillbirth. The most frequently reported cause of stillbirth was maternal factors (8-50%) including syphilis, positive HIV status with low CD4 count, malaria and diabetes. Congenital anomalies are reported to account for 2.1-33.3% of stillbirths, placental causes (7.4-42%), asphyxia and birth trauma (3.1-25%), umbilical problems (2.9-33.3%), and amniotic and uterine factors (6.5-10.7%). Seven different classification systems were identified but applied in only 22% of studies that could have used a classification system. A high percentage of stillbirths remain 'unclassified' (3.8-57.4%).

Conclusion: To build capacity for perinatal death audit, clear guidelines and a suitable classification system to assign cause of death must be developed. Existing classification systems may need to be adapted. Better data and more data are urgently needed.

Keywords: Causes of stillbirth; factors associated with stillbirth; low income countries; middle income countries; stillbirth classification.