The aim of our study was to assess associations between smoking behavior before and during pregnancy and selected adverse birth outcomes. This study is based on the Murmansk County Birth Registry (MCBR). Our study includes women who delivered a singleton pregnancy after 37 weeks of gestation (N = 44,486). Smoking information was self-reported and assessed at the first antenatal visit during pregnancy. We adjusted for potential confounders using logistic regression. The highest proportion of infants with low values of birth weight, birth length, head circumference, ponderal index and of the Apgar score at 5 min was observed for women who smoked both before and during pregnancy. We observed a dose-response relationship between the number of cigarettes smoked per day during pregnancy and the odds of the aforementioned adverse birth outcomes; neither were there significant differences in their occurrences among non-smokers and those who smoked before but not during pregnancy. Moreover, smoking reduction during pregnancy relative to its pre-gestation level did not influence the odds of the adverse birth outcomes. Our findings emphasize a continued need for action against tobacco smoking during pregnancy.

BackgroundSmoking during pregnancy leads to adverse maternal and birth outcomes. However, the prevalence of smoking among women in Russia has increased from < 5 % in the 1980s to > 20 % in the 2000s. We conducted a registry-based study in Murmansk County, Northwest Russia. Our aims were twofold: (i) assess the prevalence of smoking before and during pregnancy; and (ii) examine the socio-demographic factors associated with giving up smoking or reducing the number of cigarettes smoked once pregnancy was established.MethodsThis study employs data from the population-based Murmansk County Birth Registry (MCBR) collected during 2006–2011. We used logistic regression to investigate associations between women’s socio-demographic characteristics and changes in smoking habit during pregnancy. To avoid departure from uniform risk within specific delivery departments, we employed clustered robust standard errors.ResultsOf all births registered in the MCBR, 25.2 % of the mothers were smokers before pregnancy and 18.9 % continued smoking during pregnancy. Cessation of smoking during pregnancy was associated with education, marital status and parity but not with maternal age, place of residence, and ethnicity. Women aged ≤ 20–24 years had higher odds of reducing the absolute numbers of cigarettes smoked per day during pregnancy than those aged ≥ 30–34 years. Moreover, smoking nulliparae and pregnant women who had one child were more likely to reduce the absolute numbers of cigarettes smoked per day compared to women having ≥ 2 children.ConclusionsAbout 25.0 % of smoking women in the Murmansk County in Northwest Russia quit smoking after awareness of the pregnancy, and one-third of them reduced the number cigarettes smoked during pregnancy. Our study demonstrates that women who have a higher education, husband, and are primiparous are more likely to quit smoking during pregnancy. Maternal age and number of children are indicators that influence reduction in smoking during pregnancy. Our findings are useful in identifying target groups for smoking intervention campaigns.

In this paper, we have described the main principles of cross-sectional studies planning and data analysis. A theoretical base for cross-sectional studies' design has been presented as well as advantages and disadvantages of this type of studies. We present the methods for sample size calculation and data analysis using statistical software. Calculation of confidence intervals using free software "Epi Info" and online calculators has also been presented. The main effect measures used in cross-sectional studies have been described. Examples of cross-sectional studies in the fields of clinical medicine, dentistry and public health performed in the Arkhangelsk region have been given. The primary audience for this article consists of master and doctoral students whose research is still in the planning phase. This paper supplements, but does not substitute the literature in the field of clinical epidemiology.

BackgroundAlthough prior studies have shown that smoking reduces preeclampsia/eclampsia risk, the consequence of giving up this habit during pregnancy should be assessed. The aims of the current study were threefold: (i) describe maternal characteristics of women with preeclampsia/eclampsia; (ii) examine a possible association between the number of cigarettes smoked daily during pregnancy and the development of this affliction; and (iii) determine if first-trimester discontinuation of smoking during pregnancy influences the risk.MethodsA registry-based study was conducted using data from the Murmansk County Birth Registry (MCBR). It included women without pre-existing hypertension, who delivered a singleton infant during 2006–2011 and had attended the first antenatal visit before 12 week of gestation. We adjusted for potential confounders using logistic regression.ResultsThe prevalence of preeclampsia/eclampsia was 8.3% (95%CI: 8.0–8.6). Preeclampsia/eclampsia associated with maternal age, education, marital status, parity, excessive weight gain and body mass index at the first antenatal visit. There was a dose-response relationship between the number of smoked cigarettes per day during pregnancy and the risk of preeclampsia/eclampsia (adjusted OR1-5 cig/day = 0.69 with 95%CI: 0.56–0.87; OR6-10 cig/day = 0.65 with 95%CI: 0.51–0.82; and OR≥11 cig/day = 0.49 with 95%CI: 0.30–0.81). There was no difference in this risk among women who smoked before and during pregnancy and those who did so before but not during pregnancy (adjusted OR = 1.10 with 95%CI: 0.91–1.32).ConclusionsPreeclampsia/eclampsia was associated with maternal age, education, marital status, parity, excessive weight gain, and body mass index at the first antenatal visit. There was a negative dose-response relationship between the number of smoked cigarettes per day during pregnancy and the odds of preeclampsia/eclampsia. However, women who gave up smoking during the first trimester of gestation had the same risk of preeclampsia/eclampsia as those who smoked while pregnant. Consequently, antenatal clinic specialists are advised to take these various observations into account when counselling women on smoking cessation during pregnancy.

While sociodemographic predictors of cervical cancer (CC) are well understood, predictors of high-risk (HR) human papillomavirus (HPV) infection have not been fully elucidated. This study explored the HR-HPV infection positivity in relation to sociodemographic, sexual behavior characteristics and knowledge about HPV and CC prevention among women who visited the Arkhangelsk clinical maternity hospital named after Samoylova, Russia. This cross-sectional study was conducted in the city of Arkhangelsk, Northwest Russia. Women who consulted a gynecologist for any reason between 1 January 2015 and 30 April 2015 were residents of Arkhangelsk, 25–65 years of age were included. The Mann–Whitney and Pearson’s χ2 tests were used. To determine the HR-HPV status, we used the Amplisens HPV-DNA test. We used a questionnaire to collect the information on sociodemographic factors. Logistic regression was applied. The prevalence of HR-HPV infection was 16.7% (n = 50). HR-HPV infection was more prevalent in younger women, cohabiting, nulliparae, smokers, having had over three sexual partners and early age of sexual debut. The odds of having a positive HR-HPV status increased by 25% with an annual decrease in the age of sexual debut. Moreover women with one child or more were less likely to have positive HR-HPV status.

BackgroundKnowledge about cervical cancer (CC) risk factors and benefits of CC prevention motivates women to participate in its screening. However, several studies show that there is a significant knowledge deficit worldwide about human papillomavirus (HPV). The current study explores the level of knowledge about HPV and CC prevention in the context of sociodemographic and behavioral characteristics of women who visited an antenatal clinic in Arkhangelsk, Russia.MethodsThis cross-sectional study was conducted in the city of Arkhangelsk, which seats the administrative center of Arkhangelsk County, Northwest Russia. It included women who consulted a gynecologist for any reason between January 1, 2015 and April 30, 2015, were residents of Arkhangelsk, 25 to 65 years of age and sexually active (N = 300). Student’s t-test for continuous variables and Pearson's χ2 test for categorical variables were used in the comparisons of women grouped as having either poor or sufficient knowledge. Linear regression analysis was also employed.ResultsThe level of knowledge about HPV and CC prevention was associated with education, parity, age of initiating of intercourse, and sources of information. After adjustment, women with university education were more likely to have higher knowledge about HPV and CC prevention compared to those with lower education.ConclusionsWe observed that most participants had a sufficient level of knowledge. Educational gaps were identified that potentially could be used to tailor interventions in CC prevention.

The article presents the main methodological principles of planning, implementation and statistical analysis of data from cohort studies. Types of cohort studies, their main advantages and disadvantages, and practical examples of cohort studies in medicine and public health are also presented. We also present the main measures used in cohort studies, namely, the incidence, cumulative incidence, incidence density, absolute risk, relative risk, attributable risk and attributable risk fraction in a given cohort and in a population, incidence rate ratio and incidence rate difference. Examples of cohort studies in literature, including examples from Arkhangelsk region are presented and discussed. The methods of sample size calculation using "EpiInfoTM" software and calculation of the measures of association in cohort studies are also shown using examples from real studies. This is an introductory article about the main methodological principles of cohort study design in health sciences and it does not substitute specialized literature in clinical epidemiology.

In this paper we present definition, classification and main characteristics of qualitative research as well as its advantages and disadvantages. We also compare the main features of qualitative and quantitative study designs. Examples are given to demonstrate practical steps in qualitative inquiry to demonstrate that qualitative research can sufficiently contribute to evidence generation in medicine and public health complementing quantitative research with answers on questions "why" and "how", which cannot be answered by quantitative research. The paper presents basic information on qualitative studies and does not substitute specialized literature.