Maternal smoking is still a major public health problem posing the risk of several negative health outcomes for both the pregnant woman and her offspring. The prevalence of maternal smoking in Denmark and other high-income countries has decreased continuously since the 1980s, and a prevalence below 10% of women who continue to smoke during pregnancy has been reported in studies after 2010. Previous studies have shown that low socioeconomic status is associated with maternal smoking. Information from the Danish Birth Register about maternal smoking shows that the prevalence of women who report to smoke in pregnancy has decreased continuously with 23.3% who reported ever smoking in pregnancy in 2000, 12.9% in 2010 and 9.0% in 2017. The aim of this study was to estimate the prevalence of maternal smoking at the time of conception and at 20 weeks of gestation in a regional Danish population, to describe differences in maternal characteristics among smokers, quitters and never-smokers, and to estimate predictors of smoking at the time of conception. A cross-sectional study was conducted among pregnant women receiving antenatal care at the Department of Obstetrics, Zealand University Hospital, Denmark from August 2015 to March 2016 (n = 566). The main outcome was smoking at the time of conception and at 20 weeks of gestation. The questionnaire also collected information about maternal, health-related and sociodemographic characteristics. Descriptive analysis was conducted, and multivariate logistic regression analysis was used to assess the potential associated predictors (adjusted odds ratio). The prevalence of self-reported smoking at the time of conception was 16% (n = 90) and 6% smoked at 20 weeks of gestation (n = 35), as 61% of smokers quit smoking during early pregnancy. Multiple logistic regression analysis showed that significant predictors for smoking at conception were the socioeconomic factors; ≤12 years of education, shift work and being unemployed. The prevalence of self-reported maternal smoking in this regional Danish population of pregnant women is lower than seen in previous studies. However, predictors for smoking at the time of conception remain to be factors of low socioeconomic status confirming a social inequality in maternal smoking. Women at risk of smoking during pregnancy must be identified in early pregnancy or even before pregnancy and be offered interventions to help them quit smoking.

Low back pain is a common condition among childbearing women, causing physical disability and an increased risk of sick leave and obstetric complications. To assess the prevalence and intensity of low back pain during pregnancy, to describe the physical disability and sick leave in relation to the severity of low back pain and to identify predictors of moderate to severe low back pain in socio-demographic, health and obstetric characteristics among childbearing women. A cohort study was undertaken (n=566) during August 2015 to March 2016. Questionnaires were used to obtain information about low back pain intensity, physical disability due to low back pain and sick leave at 20 and 32weeks of gestation. Of the 654 eligible women, 87% completed the first questionnaire. Three out of four reported any low back pain at 20weeks of gestation, and nine out of ten women at 32weeks. Of these women, one in three reported moderate to severe pain at 20weeks, increasing to half of the women at 32weeks. Both sick leave and physical disability increased with increasing low back pain scores. Pre-pregnancy low back pain, multiparity and lower level of education were all identified as predictors of moderate to severe low back pain. Women with pre-pregnancy low back pain, multiparity and lower level of education, represent the group of women with the highest risk of moderate to severe low back pain during pregnancy and should be payed special attention.

Background: Physical activity (PA) during pregnancy is an effective and safe way to improve maternal health in uncomplicated pregnancies. However, compliance with PA recommendations remains low among pregnant women. Objective: The purpose of this study was to evaluate the effects of offering structured supervised exercise training (EXE) or motivational counseling on PA (MOT) during pregnancy on moderate-to-vigorous intensity physical activity (MVPA) level. Additionally, complementary measures of PA using the Pregnancy Physical Activity Questionnaire (PPAQ) and gold standard doubly labeled water (DLW) technique were investigated. The hypotheses were that both EXE and MOT would increase MVPA in pregnancy compared with standard care (CON) and that EXE would be more effective than MOT. In addition, the association between MVPA and the number of sessions attended was explored. Methods: A randomized controlled trial included 220 healthy, inactive pregnant women with a median gestational age of 12.9 (IQR 9.4-13.9) weeks. A total of 219 women were randomized to CON (45/219), EXE (87/219), or MOT (87/219). The primary outcome was MVPA (minutes per week) from randomization to the 29th gestational week obtained by a wrist-worn commercial activity tracker (Vivosport, Garmin International). PA was measured by the activity tracker throughout pregnancy, PPAQ, and DLW. The primary outcome analysis was performed as an analysis of covariance model adjusting for baseline PA. Results: The average MVPA (minutes per week) from randomization to the 29th gestational week was 33 (95% CI 18 to 47) in CON, 50 (95% CI 39 to 60) in EXE, and 40 (95% CI 30 to 51) in MOT. When adjusted for baseline MVPA, participants in EXE performed 20 (95% CI 4 to 36) minutes per week more MVPA than participants in CON (P=.02). MOT was not more effective than CON; EXE and MOT also did not differ. MVPA was positively associated with the number of exercise sessions attended in EXE from randomization to delivery (P=.04). Attendance was higher for online (due to COVID-19 restrictions) compared with physical exercise training (P=.03). Adverse events and serious adverse events did not differ between groups. Conclusions: Offering EXE was more effective than CON to increase MVPA among pregnant women, whereas offering MOT was not. MVPA in the intervention groups did not reach the recommended level in pregnancy. Changing the intervention to online due to COVID-19 restrictions did not affect MVPA level but increased exercise participation. Trial Registration: ClinicalTrials.gov NCT03679130; https://clinicaltrials.gov/ct2/show/NCT03679130 International Registered Report Identifier (IRRID): RR2-10.1136/bmjopen-2020-043671

Changing prevalence and the risk factors for antenatal obstetric hospitalizations in Denmark 2003-2012 Jane Bendix,1 Hanne Kristine Hegaard,2 Jens Langhoff-Roos,3 Thomas Bergholt3 1Department of Gynaecology and Obstetrics, Nordsjaellands Hospital Hillerod, University of Copenhagen, Hillerod, Denmark; 2The Research Unit of Women’s and Children’s Health, The Juliane Marie Centre for Women, Children and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark; 3Department of Obstetrics, The Juliane Marie Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark Purpose: Population-based studies evaluating the use and extent of antenatal obstetric hospitalizations (AOH) are sparse. The objective of the present study was to describe the prevalence, time trend, and risk factors for AOH in Denmark. Materials and methods: A retrospective national register-based cohort study was conducted that included all pregnancies with delivery after 22 gestational weeks in Denmark from 2003 to 2012. The outcomes were AOH and the diagnoses leading to these hospitalizations. AOH was defined as an antenatal hospitalization for at least 1 day with at least one obstetric International Classification of Diseases-10 diagnosis and admission date more than 3 days before delivery. Results: The study included 617,906 pregnancies; 48,366 (7.8%) pregnancies were associated with 64,072 AOH before delivery. The percentage of pregnancies with AOH decreased from 8.6% to 7.1%. The median length of stay decreased from 3 to 2 days, and admission for at least 7 days was almost halved. Threatened preterm delivery was the most frequent diagnostic category for AOH. A decline was seen in all diagnostic categories except maternal diseases. Significant risk factors for AOH were multiple pregnancies, low or high maternal age and body mass index, nulliparity, lower educational levels, unemployment or being outside the workforce, single partner status, and smoking. The relative risk of very preterm delivery before gestational age of 34 weeks was higher in pregnancies with AOH compared with pregnancies without AOH (relative risk 15.2; 95% confidence interval: 14.6–15.8). Conclusion: This study shows a shift toward less use and shorter duration of antenatal hospitalization in Denmark. The most common indication used in pregnancies with AOH was threatened preterm delivery, and more than one-third resulted in very preterm deliveries. Keywords: obstetric admissions, pregnancy complications, diagnosis, Danish health registry study, time trend

Introduction: Evidence about the consequences of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in pregnancy is rapidly increasing; however, data on antibody response and risk of transmission during pregnancy and delivery are still limited. The aim of this study was to evaluate if SARS‐CoV‐2 is detectable in vaginal swabs and whether antibodies against SARS‐CoV‐2 are present in maternal and umbilical cord blood of pregnant women with confirmed SARS‐CoV‐2.Material and methods: A single‐unit prospective cohort study in Denmark including pregnant women with SARS‐CoV‐2 infection confirmed by a pharyngeal swab between August 20, 2020, and March 1, 2021, who gave birth during the same period. All patients admitted to the maternity ward and antepartum clinic were screened for SARS‐CoV‐2 infection. A maternal blood sample and vaginal swabs were collected at inclusion. If included antepartum, these samples were repeated intrapartum when an umbilical cord blood sample was also collected. Swabs were analyzed for SARS‐CoV‐2 and blood samples were analyzed for SARS‐CoV‐2 total antibodies. Placental and neonatal swabs as well as placental histopathological examinations were performed on clinical indications.Results: We included 28 women, of whom four had serious maternal or fetal outcomes including one case of neonatal death. Within the first 8 days after confirmed SARS‐CoV‐2 infection, SARS‐CoV‐2 was detectable in two vaginal swabs (2/28) and SARS‐CoV‐2 antibodies were detected in 1 of 13 women. From 16 days after confirmed infection, antibodies were observed in 19 of 21 of women. Antibodies in cord blood were not detected during the first 16 days after confirmed infection (n = 7). However, from 26 days, antibodies were present in 16 of 17 cord blood samples of seropositive mothers. Placental examination in two cases of severe fetal outcomes preceded by reduced fetal movements revealed SARS‐CoV‐2 in swabs and severe histopathological abnormalities.Conclusions: SARS‐CoV‐2 was detected in only 2 of 28 vaginal swabs within 8 days after confirmed infection in pregnant women. Our data suggest that maternal seroconversion occurs between days 8 and 16, whereas antibodies in cord blood of seropositive mothers were present in the majority from 26 days after confirmed infection. Additional data are needed regarding timing of seroconversion for the mother and appearance of antibodies in cord blood.