Recurrence of perinatal death in Northern Tanzania: a registry based cohort study

BACKGROUND Perinatal mortality is known to be high in Sub-Saharan Africa. Some women may carry a particularly high risk which would be reflected in a high recurrence risk. We aim to estimate the recurrence risk of perinatal death using data from a hospital in Northern Tanzania. METHODS We constructed a cohort study using data from the hospital based KCMC Medical Birth Registry. Women who delivered a singleton for the first time at the hospital between 2000 and 2008 were followed in the registry for subsequent deliveries up to 2010 and 3,909 women were identified with at least one more delivery within the follow-up period. Recurrence risk of perinatal death was estimated in multivariate models analysis while adjusting for confounders and accounting for correlation between births from the same mother. RESULTS The recurrence risk of perinatal death for women who had lost a previous baby was 9.1%. This amounted to a relative risk of 3.2 (95% CI: 2.2 - 4.7) compared to the much lower risk of 2.8% for women who had had a surviving baby. Recurrence contributed 21.2% (31/146) of perinatal deaths in subsequent pregnancies. Preeclampsia, placental abruption, placenta previa, induced labor, preterm delivery and low birth weight in a previous delivery with a surviving baby were also associated with increased perinatal mortality in the next pregnancy. CONCLUSIONS Some women in Tanzanian who suffer a perinatal loss in one pregnancy are at a particularly high risk of also losing the baby of a subsequent pregnancy. Strategies of perinatal death prevention that target pregnant women who are particularly vulnerable or already have experienced a perinatal loss should be considered in future research.