Severe maternal morbidity surveillance, temporal trends and regional variation: A population-based cohort study

ObjectiveTo quantify temporal trends and regional variation in severe maternal morbidity (SMM) in Sweden.DesignCohort study.PopulationLive birth and stillbirth deliveries in Sweden, 1999-2019.MethodsTypes and subtypes of SMM were identified, based on a standard list (modified for Swedish clinical setting after considering the frequency and validity of each indicator) using diagnoses and procedure codes, among all deliveries at >= 22 weeks of gestation (including complications within 42 days of delivery). Contrasts between regions were quantified using rate ratios (RRs) and 95% confidence intervals (95% CIs). Temporal changes in SMM types and subtypes were described.Main outcome measuresTypes and subtypes of SMM.ResultsThere were 59 789 SMM cases among 2 212 576 deliveries, corresponding to 270.2 (95% CI 268.1-272.4) per 10 000 deliveries. Composite SMM rates increased from 236.6 per 10 000 deliveries in 1999 to 307.3 per 10 000 deliveries in 2006, before declining to 253.8 per 10 000 deliveries in 2019. Changes in composite SMM corresponded with temporal changes in severe haemorrhage rates, which increased from 94.9 per 10 000 deliveries in 1999 to 169.3 per 10 000 deliveries in 2006, before declining to 111.2 per 10 000 deliveries in 2019. Severe pre-eclampsia, eclampsia and HELLP (haemolysis, elevated liver enzymes and low platelet count) syndrome (103.8 per 10 000 deliveries), severe haemorrhage (133.7 per 10 000 deliveries), sepsis, embolism, disseminated intravascular coagulation, shock and severe mental health disorders were the most common SMM types. Rates of embolism, disseminated intravascular coagulation and shock, acute renal failure, cardiac complications, sepsis and assisted ventilation increased, whereas rates of surgical complications, severe uterine rupture and anaesthesia complications declined.ConclusionsThe observed spatiotemporal variations in composite SMM and SMM types provide substantive insights and highlight regional priorities for improving maternal health.

Automated summary

This study aims to examine the temporal trends and regional variation in severe maternal morbidity (SMM) in Sweden. The results showed that the composite SMM rates increased and then declined from 1999 to 2019, consistent with changes in severe hemorrhage rates. Among the SMM types, severe pre-eclampsia, severe hemorrhage, and sepsis were the most common. These findings provide important insights into the maternal health status in different regions of Sweden and highlight the need for improvement in maternal health.