Increased risk of peripartum perinatal mortality in unplanned births outside an institution: a retrospective population-based study.

BACKGROUND: Births in midwife-led institutions may reduce the frequency of medical interventions and provide cost-effective care, while larger institutions offer medically and technically advanced obstetric care. Unplanned births outside an institution and intrapartum stillbirths have frequently been excluded in previous studies on adverse outcomes by place of birth. OBJECTIVE: The objective of the study was to assess peripartum mortality by place of birth and travel time to obstetric institutions, with the hypothesis that centralization reduces institution availability but improves mortality. STUDY DESIGN: This was a national population-based retrospective cohort study of all births in Norway from 1999 to 2009 (n = 648,555) using data from the Medical Birth Registry of Norway and Statistics Norway and including births from 22 gestational weeks or birthweight ≥500 g. Main exposures were travel time to the nearest obstetric institution and place of birth. The main clinical outcome was peripartum mortality, defined as death during birth or within 24 hours. Intrauterine fetal deaths prior to start of labor were excluded from the primary outcome. RESULTS: A total of 1586 peripartum deaths were identified (2.5 per 1000 births). Unplanned birth outside an institution had a 3 times higher mortality (8.4 per 1000) than institutional births (2.4 per 1000), relative risk, 3.5 (95% confidence interval, 2.5-4.9) and contributed 2% (95% confidence interval, 1.2-3.0%) of the peripartum mortality at the population level. The risk of unplanned birth outside an institution increased from 0.5% to 3.3% and 4.5% with travel time <1 hour, 1-2 hours, and >2 hours, respectively. In obstetric institutions the mortality rate at term ranged from 0.7 per 1000 to 0.9 per 1000. Comparable mortality rates in different obstetric institutions indicated well-functioning routines for referral. CONCLUSION: Unplanned birth outside an institution was associated with increased peripartum mortality and with long travel time to obstetric institutions. Structural determinants have an important impact on perinatal health in high-income countries and also for low-risk births. The results show the importance of skilled birth attendance and warrant attention from clinicians and policy makers to negative consequences of reduced access to institutions.

Severity of maternal SARS-CoV-2 infection and perinatal outcomes of women admitted to hospital during the omicron variant dominant period using UK Obstetric Surveillance System data: prospective, national cohort study.

Objectives: To describe the severity of maternal infection when the omicron SARS-CoV-2 variant (B.1.1.529) was dominant (15 December 2021 to 14 March 2022) and describe outcomes by symptoms and vaccination status. Design: Prospective, national cohort study using the UK Obstetric Surveillance System. Setting: 94 hospitals in the UK with a consultant led maternity unit. Participants: Pregnant women admitted to hospital for any cause with a positive SARS-CoV-2 test. Main outcome measures: Symptomatic or asymptomatic infection, vaccination status by doses before admission, and severity of maternal infection (moderate or severe infection according to modified World Health Organization's criteria). Results: Of 3699 women who were admitted to hospital, 986 (26.7%, 95% confidence interval 25.3% to 28.1%) had symptoms; of these, 144 (14.6%, 12.5% to 17.0%) had a moderate to severe infection, 99 (10.4%, 8.6% to 12.5%) of 953 received respiratory support, and 30 (3.0%, 2.1% to 4.3%) were admitted to an intensive care unit. Covid-19 specific drug treatment was given to 13 (43.3%) of the 30 women in intensive care. Four women with symptoms died (0.4%, 0.1% to 1.1%). Vaccination status was known for 845 (85.6%) women with symptoms; 489 (58.9%) were unvaccinated and only 55 (6.5%) had three doses. Moderate to severe infection was reported for 93 (19.0%) of 489 unvaccinated women with symptoms, decreasing to three (5.5%) of 55 after three doses. Among the 30 women with symptoms who were admitted to intensive care, 23 (76.7%) were unvaccinated and none had received three doses. Conclusion: Most women with severe covid-19 disease were unvaccinated and vaccine coverage among pregnant women admitted to hospital with SARS-CoV-2 was low. Ongoing action to prioritise and advocate for vaccine uptake in pregnancy is essential. A better understanding of the persistent low use of drug treatments is an urgent priority. Trial registration: ISRCTN 40092247.

Risk of eclampsia or HELLP-syndrome by institution availability and place of delivery - A population-based cohort study.

OBJECTIVE: To examine the association between availability of obstetric institutions and risk of eclampsia, HELLP-syndrome, or delivery before 35 gestational weeks in preeclamptic pregnancies. STUDY DESIGN: National population-based retrospective cohort study of deliveries in Norway, 1999-2009 (n = 636738) using data from The Medical Birth Registry of Norway and Statistics Norway. Main exposures were institution availability, measured by travel time to the nearest obstetric institution, and place of delivery. We computed relative risks (RR) with 95% confidence intervals (CI) using travel time ≤1 h as reference. We stratified analyses by parity and preeclampsia, and adjusted for socio-demographic and medical risk factors. Successive deliveries were linked using the national identification number. RESULTS: We identified 1387 eclampsia/HELLP cases (0.2%) and 3004 (0.5%) deliveries before 35 weeks in preeclamptic pregnancies. Nulliparous women living >1 h from any obstetric institution had 50% increased risk of eclampsia/HELLP (0.50 versus 0.35%, adjusted RR 1.5; 95 %CI 1.1-1.9). Parous women living >1 h from emergency institutions had a doubled risk of eclampsia (0.6‰ versus 0.3‰, adjusted RR 2.0; 1.2-3.3). Women without preeclampsia in the present pregnancy or history of preeclampsia constituted all eclampsia/HELLP cases in midwife-led institutions, 39-50% of cases in emergency institutions, and 78% of cases (135/173) in subsequent deliveries. Women with risk factors delivered in the emergency institutions, indicating well-implemented selective referral. CONCLUSION: The study shows the importance of available obstetric institutions. Policymakers and clinicians should consider the distribution of potential benefits and burdens when planning and evaluating the obstetric health service structure.