ABSTRACT
In Denmark, a nationwide COVID-19 lockdown was implemented on March 12, 2020 and eased on April 14, 2020. The COVID-19 lockdown featured reduced prevalence of extremely preterm or extremely low birth weight births. Here we explore the impact of this COVID-19 lockdown on term birth weights in Denmark. We conducted a nationwide register-based cohort study on 27,870 live singleton infants, born at term (weeks 37-41), between March 12 and April 14, 2015-2020, using data from the Danish Neonatal Screening Biobank. Primary outcomes, corrected for confounders, were birth weight, small-for-gestational-age (SGA), and large-for-gestational-age (LGA), comparing the COVID-19 lockdown to the previous five years. Data were analysed using linear regression to assess associations with birth weight. Multinomial logistic regression was used to assess associations with size-for-gestational-age (xGA) categories. Adjusted mean birth weight was significantly increased by 16.9 g (95% CI = 4.1 - 31.3) during the lockdown period. A dip in mean birth weight was found in gestational weeks 37 and 38 balanced by an increase in weeks 40 and 41. The 2020 lockdown period was associated with an increased LGA prevalence (aOR 1.13, 95% CI = 1.05 - 1.21). No significant changes in proportions of xGA groups were found between 2015 and 2019. Conclusion: The nationwide COVID-19 lockdown resulted in a small but significant increase in birth weight and proportion of LGA infants, driven by an increase in birth weight in gestational weeks 40 and 41.
Subject(s)
COVID-19 , Birth Weight , Abnormalities, Drug-InducedABSTRACT
Denmarks response to the COVID-19 pandemic was to issue guidelines on containment, isolation, and surveillance. Subsequently, Denmark entered a period with variable mitigation measures including closures of schools and workplaces, travel restrictions, and restrictions on public gatherings. A Danish study covering the lockdown period (March 12 - April 14, 2020) as well as a period of mitigation measures (February 27 - September 30, 2020) showed that the reduction in extremely preterm births was not associated with an increase in singleton stillbirth rate. Subsequent studies examining the impacts of COVID-19 mitigation measures on preterm birth have combined singleton with multifetal pregnancies. However, multifetal pregnancies have a different set of risk factors for preterm birth, as well as, increased risk of adverse outcomes, and a shorter expected pregnancy length. We assessed the impact of the Danish lockdown period, or the mitigation period on multifetal births and found no significant difference in the proportion of preterm twin births among all twin births, either within gestational age groups or in total, for either period.
Subject(s)
COVID-19ABSTRACT
Objectives: COVID-19 policies have been employed in Denmark since March 2020. We examined whether COVID-19 restrictions had an impact on Chlamydia trachomatis infections compared with 2018 and 2019. Methods: This retrospective nation-wide Danish observational study was performed using monthly incidences of laboratory confirmed chlamydia cases and number of tests, obtained from nation-wide surveillance data. Additionally, Oxford COVID-19 Government Response Tracker data, and Google COVID-19 Community Mobility Reports were used to contextualise the behavioural adaptions seen as a result of COVID-19 policies. Testing rates were compared using Poisson regression and test positivity rates were compared using logistic regression. Results: The crude incidence rate (IR) of laboratory confirmed chlamydia infections was reduced to 66.5 per 105 during the first (March-April 2020) lockdown period as compared to 88.3 per 105 in March-April 2018-2019, but the testing rate was also reduced (Rate ratio 0.72 95% CI 0.71-0.73), whereas the odds ratio for a positive test between the two periods was 0.98 (95% CI 0.96-1.00). The period of eased COVID 19 restrictions (May-December 2020) and the second lockdown period (December 2020-March 2021) were characterised by marginally increased crude IRs, while the number of tests performed, and test positivity rates returned very close to the levels seen in 2018-2019. These results were independent of sex, age group, and geographical location. Conclusion: The first Danish COVID-19 lockdown resulted in a reduction in the number of chlamydia tests performed and a consequent reduction in the number of laboratory-identified cases. This period was followed by a return of testing and test positivity close to the level seen in 2018-2019. Altogether the Danish COVID-19 restrictions have had negligible effects on laboratory confirmed C. trachomatis transmission.
Subject(s)
COVID-19 , Chlamydia InfectionsABSTRACT
Importance Using provisional or opportunistic data, three nationwide studies (The Netherlands, USA, and Denmark) have identified a reduction in preterm or extremely preterm births during periods of COVID-19 restrictions. However, these findings have been challenged as none of the studies accounted for perinatal deaths. Objective To determine whether the reduction in extremely preterm births, observed in Denmark during the COVID-19 lockdown, could be a result of an increase in number of perinatal deaths; and to assess the impact of extended COVID-19 restrictions on the prevalence of preterm birth and perinatal death. Design The study is a nationwide Danish register-based prevalence proportion study using detailed data to capture all births (induced abortions were excluded) throughout Denmark. We assessed the prevalence of stillbirth, preterm birth, and early neonatal death. Setting Population-based study Participants All singleton pregnancies delivered in Denmark, between February 27, and September 30, 2015-2020. COVID-19 lockdown was studied in 31,164 births and the extended period of COVID-19 restrictions in 214,862 births. Exposure COVID-19 restrictions broadly (February 27, – September 30, 2020) or COVID-19 lockdown specifically (March 12, – April 14, 2020). Main Outcome Prevalence of preterm births, stillbirths and early neonatal deaths across the periods under study. Results The extremely preterm birth rate was reduced (OR 0.27, 95% CI 0.07 to 0.86) during the strict lockdown period, while perinatal mortality was not significantly different. During the extended period of restrictions, the extremely preterm birth rate was marginally reduced, and a significant reduction in the stillbirth rate (OR 0.69, 0.50 to 0.95) was observed. No changes in early neonatal mortality rates were found. Conclusion and Relevance Stillbirth and extremely preterm birth rates were reduced in Denmark during the period of COVID-19 restrictions and lockdown, respectively, suggesting that aspects of these containment and control measures confer an element of protection. The present observational study does not allow for causal inference; however, the results support design of studies to ascertain whether behavioural or social changes for pregnant women may improve pregnancy outcomes. Funding None Key points Question Can changes in stillbirth and early neonatal mortality rates during the COVID-19 lockdown explain the reduction in extremely preterm birth seen in Denmark? Findings In this nationwide register-based study that included data pertaining to 245,999 pregnancies, the statistically significant reduction in extremely preterm birth during the COVID-19 lockdown was confirmed. The stillbirth and early neonatal mortality rates were unchanged during lockdown, while the stillbirth rate was reduced over the extended period of COVID-19 restrictions. Meaning The reduction in extremely preterm births seen during the COVID-19 lockdown in Denmark is not a result of increased stillbirth or early neonatal death.
Subject(s)
COVID-19ABSTRACT
Introduction Assessing the risk factors for and consequences of infection with SARS-CoV-2 during pregnancy is essential to guide clinical guidelines and care. Previous studies on the influence of SARS-CoV-2 infection in pregnancy have been among hospitalised patients, which may have exaggerated risk estimates of severe outcomes because all cases of SARS-CoV-2 infection in the pregnant population were not included. The objectives of this study were to identify risk factors for and outcomes after SARS-CoV-2 infection in pregnancy independent of severity of infection in a universally tested population, and to identify risk factors for and outcomes after severe infection requiring hospital admission. Material and Methods This was a prospective population-based cohort study in Denmark using data from the Danish National Patient Register and Danish Microbiology Database and prospectively registered data from medical records. We included all pregnancies between March 1 and October 31, 2020 and compared women with a positive SARS-CoV-2 test during pregnancy to non-infected pregnant women. Cases of SARS-CoV-2 infection in pregnancy were both identified prospectively and through register linkage to secure that all cases were identified and that cases were pregnant during infection. Main outcome measures were pregnancy, delivery, maternal, and neonatal outcomes. Severe infection was defined as hospital admission due to COVID-19. Results Among 82 682 pregnancies, 418 women had SARS-CoV-2 infection during pregnancy, corresponding to an incidence of 5.1 per 1000 pregnancies, 23 (5.5%) of which required hospital admission due to COVID-19. Risk factors for infection were asthma (OR 2.19 [1.41–3.41]) and being foreign born (OR 2.12 [1.70–2.64]). Risk factors for hospital admission due to COVID-19 included obesity (OR 2.74 [1.00–7.51]), smoking (OR 4.69 [1.58–13.90]), infection after gestational age (GA) 22 weeks (GA 22–27 weeks: OR 3.77 [1.16–12.29]; GA 28–36 weeks: OR 4.76 [1.60–14.12]) and having asthma (OR 4.53 [1.39–14.79]). We found no difference in any obstetric or neonatal outcomes. Conclusions Only 1 in 20 women with SARS-CoV-2 infection during pregnancy require admission to hospital due to COVID-19. And severe outcomes of SARS-CoV-2 infection in pregnancy are rare. Key Message Population based cohort study about SARS-CoV-2 infection during pregnancy. Asthma and foreign ethnicity were identified as risk factors for infection while obstetric outcomes did not change. Obesity, smoking, infection after GA 22, and asthma increased the risk of hospital admission.
Subject(s)
COVID-19 , ObesityABSTRACT
Introduction Population-based studies about the consequences of SARS-CoV-2 infection (COVID-19) in pregnancy are few and have limited generalizability to the Nordic population and health care systems. Material and method This study examines pregnant women with COVID-19 in the five Nordic countries. Pregnant women were included if they were admitted to hospital between March 1 and June 30, 2020 and had a positive SARS-CoV-2 PCR test 14 days or fewer prior to the admission. Cause of admission was classified as either obstetric or COVID-19 related. Results In the study areas, 214 pregnant women with a positive test were admitted to hospital, of which 56 women needed hospital care due to COVID-19. The rate of admission due to COVID-19 was 0.4 per 1000 deliveries in Denmark, Finland, and Norway and 3.8 per 1000 deliveries in the Swedish regions. Women hospitalized because of COVID-19 were more frequently obese (P < 0.001) and had migrant background (P < 0.001) compared to the total population of women who delivered in 2018. Twelve women (21.4%) needed intensive care. Preterm delivery (n=12, 25%, P < 0.001) and cesarean delivery (n=21, 43,8%, P < 0.001) were more frequent in women with COVID-19 compared to the women who delivered in 2018. No maternal deaths, stillbirths or neonatal deaths were reported. Conclusion The risk of admission due to severe COVID-19 disease in pregnancy was low in the Nordic countries. A fifth of the women required intensive care and we observed higher rates of preterm and cesarean deliveries. National public health policies appear to have had an impact on the rates of admission due to severe COVID-19 disease in pregnancy. Nordic collaboration is important in collecting robust data and assessing rare outcomes.
Subject(s)
Obesity , COVID-19 , StillbirthABSTRACT
BackgroundOnly few studies have focused on serological testing for SARS-CoV-2 in pregnant women and no previous study has investigated the frequency in partners. The aim was to investigate the frequency and impact of SARS-CoV-2 in parturient women, their partners and newborns. MethodsFrom April 4th to July 3rd, 2020, all parturient women, their partners and newborns were invited to participate in the study. Participating women and partners had a pharyngeal swab and a blood sample taken at admission and immediately after delivery a blood sample was drawn from the umbilical cord. The swabs were analyzed for SARS-CoV-2 RNA by PCR and the blood samples were analyzed for SARS-CoV-2 antibodies. Full medical history, obstetric- and neonatal information were available. ResultsA total of 1,361 parturient women, 1,236 partners and 1,342 newborns participated in the study. No associations between previous COVID-19 disease and obstetric- or neonatal complications were found. The adjusted serological prevalence was 2.9% in women and 3.8% in partners. The frequency of blood type A was significantly higher in women with antibodies compared to women without antibodies. 17 newborns had SARS-CoV-2 IgG antibodies, and none had IgM antibodies. Full serological data from 1,052 families showed an absolute risk of infection of 0.37 if the partner had antibodies. Only 55% of individuals with antibodies reported symptoms. ConclusionThis large prospective cohort study reports no association between COVID-19 and obstetric- or neonatal complications. The family pattern showed a substantial increase in absolute risk for women living with a partner with antibodies.