SARS-CoV-2 infection during pregnancy and perinatal outcomes in Estonia in 2020 and 2021: A register-based study.

INTRODUCTION: Data from different countries show partly controversial impact of SARS-CoV-2 infection on pregnancy outcomes. A nationwide register-based study was conducted in Estonia to assess the impact of SARS-CoV-2 infection at any time during pregnancy on stillbirth, perinatal mortality, Apgar score at 5 minutes, cesarean section rates, rates of preterm birth and preeclampsia. MATERIAL AND METHODS: Data on all newborns and their mothers were obtained from the Estonian Medical Birth Registry, and data on SARS-CoV-2 testing dates, test results and vaccination dates against SARS-CoV-2 from the Estonian Health Information System. Altogether, 26 211 births in 2020 and 2021 in Estonia were included. All analyses were performed per newborn. Odds ratios with 95% confidence intervals (CI) were analyzed for all outcomes, adjusted for mother's place of residence, body mass index, age of mother at delivery and hypertension and for all the aforementioned variables together with mother's vaccination status using data from 2021 when vaccinations against SARS-CoV-2 became available. For studying the effect of a positive SARS-CoV-2 test during pregnancy on preeclampsia, hypertension was omitted from the models to avoid overadjustment. RESULTS: SARS-CoV-2 infection during pregnancy was associated with an increased risk of stillbirth (adjusted odds ratio [aOR] 2.81; 95% CI 1.37-5.74) and perinatal mortality (aOR 2.34; 95% CI 1.20-4.56) but not with a lower Apgar score at 5 minutes, higher risk of cesarean section, preeclampsia or preterm birth. Vaccination slightly decreased the impact of SARS-CoV-2 infection during pregnancy on perinatal mortality. CONCLUSIONS: A positive SARS-CoV-2 test during pregnancy was associated with higher rates of stillbirth and perinatal mortality in Estonia but was not associated with change in preeclampsia, cesarean section or preterm birth rates.

Effect of Pap-smear and sociodemographic factors on cervical cancer risk in Estonia: A population-based case-control study.

BACKGROUND: Like many Eastern-European countries, Estonia struggles with ineffective cervical cancer (CC) screening. Despite a long-term organised screening programme and high overall Pap-smear coverage, CC incidence and mortality remain very high. The aim of the study was to examine the reasons for high CC incidence in Estonia by analysing the effect of Pap-smears and sociodemographic factors on CC risk. METHODS: In this population-based case-control study, women aged ≥ 25 years with an in situ/invasive CC diagnosed in Estonia in 2011-2017 were defined as cases. Using a density sampling scheme, controls were randomly selected from general population. To estimate CC risk associated with having no Pap-smears during seven years before diagnosis (cases) or index date (controls), place of residence, interruption in health insurance, and several sociodemographic factors, multivariate logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Individual-level data from three population-based registries were used. RESULTS: Among 1439 cases and 4317 controls, proportion of women with no Pap-smears was 53% and 35%, respectively. Women with no Pap-smears were at higher risk for CC (OR=2.35; 95% CI: 1.85-2.98). CC risk was increased among women who were younger, living in more remote regions, lower-educated, or divorced/widowed. Interruption in health insurance was associated with a 23% risk increase. Regional differences in CC risk were observed among screened women. CONCLUSION: To reduce the risk of CC in Estonia, efforts are necessary to increase screening coverage among high-risk women and ensure the quality of CC screening programme. Screening approaches and communication should be tailored to the needs of different population groups. Further studies are warranted to identify the reasons for regional differences in CC risk.