Secular trends in pregnancy outcomes in 1980–1999 in the Komi Republic, Russia

Secular trends of socio-demographic and lifestyle characteristics among delivering women in Arctic Russia, 1973-2017

The aim of this study was to describe temporal trends in socio-demographic and lifestyle characteristics among delivering women in two Northern provinces of Russia from 1973 to 2017. Totally 161,730 births were registered in three birth registries. Changes in the distribution of maternal age, education, marital status, smoking during pregnancy were studied using Pearson's chi-squared tests and one-way ANOVA. The logistic regression models were used to assess factors, contributing to the variations in the prevalence of maternal smoking. The mean age of primiparous mothers increased from 22.1 years in 1973-1980 to 25.4 years in 2012-2017 (p < 0.001). The proportion of primiparous mothers with higher education increased from 26.2% in 2006 to 38.3% in 2017 (p < 0.001). The proportion of cohabiting primiparous women increased from 5.0% to 15.2% over the study period (p < 0.001). The proportion of mothers smoking during pregnancy decreased from 18.9% in 2006-2011 to 14.8% in 2012-2017 (p < 0.001). Downward in the prevalence of smoking was revealed in 2012-2017 compared to 2006-2011 (OR = 137.76; 95%CI:71.62-264.96, OR = 183.74; 95%CI:95.52-353.41, respectively). Over the past decades, women postpone childbearing until receiving higher education, continue living in cohabitation during pregnancy and smoke less.

Maternal Risk Factors for Preterm Birth in Murmansk County, Russia: A Registry-Based Study

BACKGROUND

Globally, about 11% of all liveborn infants are preterm. To date, data on prevalence and risk factors of preterm birth (PTB) in Russia are limited. The aims of this study were to estimate the prevalence of PTB in Murmansk County, Northwestern Russia and to investigate associations between PTB and selected maternal factors using the Murmansk County Birth Registry.

METHODS

We conducted a registry-based study of 52 806 births (2006-2011). In total, 51 156 births were included in the prevalence analysis, of which 3546 were PTBs. Odds ratios with 95% confidence intervals of moderate-to-late PTB, very PTB and extremely PTB for a range of maternal characteristics were estimated using multinomial logistic regression, adjusting for potential confounders.

RESULTS

The overall prevalence of PTB in Murmansk County was 6.9%. Unmarried status, prior PTBs, spontaneous and induced abortions were strongly associated with PTB at any gestational age. Maternal low educational level increased the risk of extremely and moderate-to-late PTB. Young (<18 years) or older (≥35 years) mothers, graduates of vocational schools, underweight, overweight/obese mothers, and smokers were at higher risk of moderate-to-late PTB. Secondary education, alcohol abuse, diabetes mellitus, or gestational diabetes were strongly associated with moderate-to-late and very PTB.

CONCLUSIONS

The observed prevalence of PTB (6.9%) in Murmansk County, Russia was comparable with data on live PTB from European countries. Adverse prior pregnancy outcomes, maternal low educational level, unmarried status, alcohol abuse, and diabetes mellitus or gestational diabetes were the most common risk factors for PTB.

SECULAR CHANGES IN BIRTH WEIGHTS AND WOMEN’S BODY SIZE IN KRAKÓW AND POZNAŃ (POLAND) DURING THE LAST CENTURY

Changing socioeconomic conditions over the last century have left their mark on neonatal size and final body size of individuals born in those days. The main aim of this study was to investigate how the historical, political and economic changes occurring from the late 19th century to the 2000s have affected the birth weight of newborns. Additionally, changes in weight and body height in the case of young women (potential mothers) were analysed. Data were from two cities in Poland (Kraków and Poznań) covering 15,884 newborns and 3612 women aged 18 years, derived from 1900 to 2010. Despite short-term fluctuations, the results showed significant increasing trends in all studied features. Changes in birth weight were similar in both cities: in Kraków it increased by 184 g (males) and 206 g (females), and in Poznań by 216 g (males) and 120 g (females). Changes in women’s body size were also significant, but the level was different depending on place of residence. In the last century, women’s body height increased by 8.2 cm in Kraków and by 10.2 cm in Poznań, and their body weight increased by 1 kg and 5 kg respectively. The considered period covered the years of socioeconomic change that occurred as a result of the political system transformation. Crises, periods of prosperity and other factors that determine standard of living and health care have influenced the development of the Polish population’s physical features.

Early pregnancy body mass index and spontaneous preterm birth in Northwest Russia: a registry-based study

Background

International studies on the association between maternal body mass index (BMI) and spontaneous preterm birth (PTB) yield controversial results warranting large studies from other settings. The aim of this article was to study association between maternal early pregnancy BMI and the risk of spontaneous PTB in Murmansk County (MC), Northwest Russia.

Methods

This is a registry-based cohort study. All women with singleton pregnancies registered at antenatal clinics during the first 12 weeks of gestation and who delivered in MC between January, 1^st 2006 and December, 31^st 2011 comprised the study base (n = 29,709). All women were categorized by BMI into four groups: underweight (<18.5 kg/m²), normal (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obese (≥30.0 kg/m²). Multivariable logistic regression was used to study associations between maternal BMI and PTB (<37 weeks) and very preterm birth (VPTB) (<32 weeks) adjusted for socio-economic factors, biological and lifestyle characteristics.

Results

The prevalence of underweight, overweight and obesity were 7.1% (95% CI: 6.8-7.4), 18.3% (95% CI: 17.8-18.7) and 7.1% (95% CI: 6.8-7.4), respectively. Altogether, 5.5% (95% CI: 5.3-5.8) of the births were PTB and 0.8% (95% CI: 0.7-0.9) were VPTB. After adjustment, both underweight (OR = 1.25, 95% CI: 1.03-1.50), overweight (OR = 1.10, 95% CI: 0.97-1.26) and obese (OR = 1.31, 95% CI: 1.08-1.57) women were more likely to deliver preterm. VPTB was associated with overweight (OR = 1.47, 95% CI: 1.056-2.03) and obesity (OR = 1.63, 95% CI: 1.02-2.60).

Conclusion

The findings demonstrate a J-shaped association between first trimester maternal BMI and spontaneous PTB and VPTB with increased risk among underweight, overweight and obese women.

How many low birthweight babies in low- and middle-income countries are preterm?

OBJECTIVE: To assess the prevalence of preterm birth among low birthweight babies in low and middle-income countries. METHODS: Major databases (PubMed, LILACS, Google Scholar) were searched for studies on the prevalence of term and preterm LBW babies with field work carried out after 1990 in low- and middle-income countries. Regression methods were used to model this proportion according to LBW prevalence levels. RESULTS: According to 47 studies from 27 low- and middle-income countries, approximately half of all LBW babies are preterm rather than one in three as assumed in studies previous to the 1990s. CONCLUSIONS: The estimate of a substantially higher number of LBW preterm babies has important policy implications in view of special health care needs of these infants. As for earlier projections, our findings are limited by the relative lack of population-based studies.

Anemia in pregnancy and its association with pregnancy outcomes in the Arctic Russian town of Monchegorsk, 1973-2002

OBJECTIVES

The purpose of this study was to determine the prevalence of anemia in pregnancy in Monchegorsk, north-west Russia, and to analyse its association with birth weight and the risk of stillbirth and preterm birth.

STUDY DESIGN

A registry study based on the Kola Birth Registry.

METHODS

A total of 24,525 women who gave birth in Monchegorsk between 1973 and 2002 and who had data on anemia in pregnancy in the Kola Birth Registry (KBR) were included in the study. For these women, data on maternal anemia, age, occupation, marital status, parity, smoking, alcohol, gestational age, birth weight, stillbirth and year of delivery were obtained from the KBR. Linear regression was used to study the effect of maternal anemia on birth weight. Logistic regression was used to estimate the effect of anemia on the risks of stillbirth and preterm birth, with adjustment for the above-mentioned characteristics. Crude and adjusted odds ratios (OR) were calculated.

RESULTS

The prevalence of anemia increased from 43.7% in the 1970s to 89.8% in the beginning of the 2000s. Infants born to women with anemia were 48 grams (95% CI 36, 59) heavier than infants of non-anemic women. Women with anemia in pregnancy were less likely to have stillbirths (OR=0.68; 95% CI 0.52, 0.89) and preterm births (OR=0.66; 95% CI 0.58, 0.75) after adjustment for potential confounders.

CONCLUSION

The prevalence of anemia in pregnant women as defined by the KBR more than doubled during the 30-year period. Positive associations with birth weight and negative associations with the risk of stillbirth and live preterm birth were observed.