Socioeconomic differences in the association between maternal age and maternal obesity: a register-based study of 707,728 women in Finland.

AIMS: To examine the association between maternal age and maternal obesity across socioeconomic groups and to determine whether socioeconomic status modifies the association between maternal age and maternal obesity with a view to informing public health policies. METHODS: Data for this register-based study were sourced from the Finnish Medical Birth Register and Statistics Finland, using the information of 707,728 women who gave birth in Finland from 2004 to 2015. We used multivariable regression models to assess the association between maternal age and maternal obesity across socioeconomic groups. We further assessed interactions on both multiplicative and additive scales. RESULTS: Across all socioeconomic groups, the adjusted odds ratio for the association between maternal age and maternal obesity increased, peaking for women 35 years or older. Using women below 20 years of age in the category of upper-level employees as a single reference group, in the category of upper-level employees, the adjusted odds ratio and 95% confidence intervals among women 35 years or older was 1.92 (1.39-2.64) for maternal obesity. Equally, the adjusted odds ratio and 95% confidence intervals in the category of long-term unemployed was 4.35 (3.16-5.98). Synergistic interactions on both multiplicative and additive scales were found across age and socioeconomic groups. CONCLUSIONS: The association between maternal age and maternal obesity was strongest among women 35 years or older with lower socioeconomic status. Population-level interventions that address maternal risk factors from teenage years are needed alongside individual-level interventions that target high-risk mothers in areas of low socioeconomic status and maternal obesity.

Educational achievement of children with selected major congenital anomalies and associated factors: a Finnish registry-based study.

BACKGROUND: Children with major congenital anomalies may be at risk of poor educational outcomes. We aimed to evaluate the educational achievement of children born with major congenital anomalies compared with children without major congenital anomalies in relation to sociodemographic factors. METHODS: We performed a registry-based study including 401 544 children in Finland, graduates of the compulsory school who applied to secondary education. We used health data from the Finnish Register of Congenital Malformations for children born from 1995 to 2002 linked with education data from the Finnish Ministry of Education and Culture. We used generalized linear regression to compare the mean grade differences of children with specific major congenital anomalies and 'All anomalies' subgroup (major congenital anomalies, chromosomal syndromes, and multiple anomalies) with reference children. RESULTS: Children with major congenital anomalies were less likely to apply for further education than reference children (88.0% vs. 96.8%; odds ratio = 4.13; 95% confidence interval, 3.92-4.36). For most non-chromosomal congenital anomalies, children born with congenital anomalies had similar educational achievement to the reference children. For the 'All anomalies' subgroup, children with congenital anomalies had lower educational achievement than reference children. Among children with congenital anomalies, male sex, lower maternal educational levels and younger maternal age were associated with lower educational achievement. CONCLUSIONS: For children applying to further education, most non-chromosomal congenital anomalies were not associated with lower educational achievement. Nevertheless, efforts are needed to improve educational achievement in children with major congenital anomalies associated with maternal sociodemographic background.

Socioeconomic status, maternal risk factors, and gestational diabetes mellitus across reproductive years: a Finnish register-based study.

INTRODUCTION: To evaluate the degree to which socioeconomic differences in gestational diabetes mellitus (GDM) are accounted for by differences in maternal risk factors, to assess whether age-related risks of GDM differ across socioeconomic groups, and to identify priority populations for future interventions. RESEARCH DESIGN AND METHODS: We performed a register-based study using data from the Finnish Medical Birth Register and Statistics Finland on the 474 166 women who gave birth in Finland from 2008 to 2015. We collected information on GDM based on the International Classification of Diseases 10th Revision codes O24.4 and O24.9. We used multivariable models to examine the association between socioeconomic status, maternal risk factors, and GDM. We further tested interaction on multiplicative and additive scales. RESULTS: The incidence of GDM was 8.7% in 2008-2011 and 12.5% in 2012-2015. Lower socioeconomic levels than upper level employees were associated with an increased risk of GDM. Up to 64.0% of socioeconomic differences in GDM were attributed to body mass index and 5.5% to smoking. There was evidence for effect modification. Relative to women in the upper level category who were aged less than 19 years, GDM adjusted ORs (95% CIs) for women 35 years or older in upper level versus long-term unemployed groups were 3.28 (2.08-5.18) and 5.29 (3.35-8.35), respectively. CONCLUSIONS: There is a paradox that socioeconomic advantage increases the incidence of GDM at the population level while reducing the incidence of GDM within the population. Nevertheless, socioeconomic differences in GDM persist and widen with increasing maternal age, even after accounting for maternal risk factors.

Associations between maternal age and socioeconomic status with smoking during the second and third trimesters of pregnancy: a register-based study of 932 671 women in Finland from 2000 to 2015.

OBJECTIVES: This study aimed to explore the association between maternal age and smoking during the second and third trimesters of pregnancy across socioeconomic groups and to evaluate the interacting effect of maternal age and socioeconomic status on smoking with a view to informing public health interventions. DESIGN: This is a register-based study. SETTINGS: Data from the Finnish Medical Birth Register were cross-linked with background data from Statistics Finland. PARTICIPANTS: The information of 932 671 pregnant women who gave birth in Finland from 2000 to 2015. MAIN OUTCOME MEASURES: Maternal smoking during the second and third trimesters of pregnancy by occupation and maternal age. RESULTS: The proportion of women who smoked during the second and third trimesters of pregnancy was 10.5%. Using women 30-34 years as the reference group, adjusted ORs (aOR) and 95% CIs for smoking were 6.02 (5.81 to 6.24) in women below 20 years and 2.77 (2.71 to 2.84) in women 20 to 24 years. The prevalence of smoking across socioeconomic groups compared with upper-level employees increased, peaking for women in manual occupations (aOR 3.39, 95% CI 3.25 to 3.52) and unemployed women (aOR 4.49, 95% CI 4.30 to 4.68). Significant interactions on the additive scale with the relative excess risk due to interaction >2 were found for unemployed women aged 25-29 years and for teenage mothers and mothers aged 20-24 years across all socioeconomic groups, but not for self-employed women. CONCLUSIONS: Smoking during the second and third trimesters of pregnancy was most common among teenage mothers across all socioeconomic groups. The association between maternal age and smoking differed by socioeconomic status for young mothers. Interventions should address a wider range of maternal risk factors among young mothers with low socioeconomic status and simultaneously target a broader number of women who smoke during the pregnancy.

Fertility rates and the postponement of first births: a descriptive study with Finnish population data.

OBJECTIVES: We described the trend of fertility rates, age-specific fertility rates and associated factors in Finland over a 30-year period. DESIGN: A descriptive population-based register study. SETTING: Fertility data, including age at first birth, childlessness and educational levels were gathered from the Finnish Medical Birth Register and Statistics Finland. PARTICIPANTS: All 1 792 792 live births from 1987 to 2016 in Finland. MAIN OUTCOME MEASURES: Completed fertility rate, total fertility rate and age-specific fertility rate. RESULTS: The total fertility rate of Finnish women fluctuated substantially from 1987 to 2016. Since 2010, the total fertility rate has gradually declined and reached the lowest during the study period in 2016: 1.57 children per woman. The mean maternal age at first birth rose by 2.5 years from 26.5 years in 1987 to 29 years in 2016. The proportion of childless women at the age of 50 years increased from 13.6% in 1989 to 19.6% in 2016. By considering the impact of postponement and childlessness, the effect on total fertility rates was between -0.01 and -0.12 points. Since 1987, the distribution of birth has declined for women under the age of 29 and increased for women aged 30 or more. However, start of childbearing after the age of 30 years was related to the completed fertility rate of less than two children per woman. The difference in completed fertility rate across educational groups was small. CONCLUSIONS: Postponement of first births was followed by decline in completed fertility rate. Increasing rate of childlessness, besides the mean age at first birth, was an important determinant for declined fertility rates, but the relation between women's educational levels and the completed fertility rate was relatively weak.

The effect of advanced maternal age on maternal and neonatal outcomes of placenta previa: A register-based cohort study.

OBJECTIVES: Advanced maternal age (AMA) at the time of delivery generally worsens obstetric outcomes, but its effects on specific pregnancy problems, such as placenta previa, have not been adequately assessed. Therefore, the objective of the study was to explore the effect of AMA on adverse maternal and neonatal outcomes among pregnancies complicated by placenta previa. STUDY DESIGN: The study was a register-based cohort study using data of three Finnish health registries, including information of 283 324 women and their newborns. Separate multivariable logistic regression modeling was performed for women under age 35 and women aged 35 or older to assess the association between placenta previa and adverse maternal and neonatal outcomes. Furthermore, interactions between maternal age and placenta previa were tested. RESULTS: A total of 283 324 deliveries of which 714 (0.3%) were complicated by placenta previa. Adverse maternal and neonatal outcomes increased in women with placenta previa, with different patterns across age groups. The adjusted odds ratios and 95% confidence intervals for AMA and young women with previa were 7.3 (5.0-10.6) and 6.8 (5.2-8.9) in blood transfusion, 11.3 (5.4-23.3) and 10.9 (6.1-19.6) in placental abruption. In neonatal outcomes the adjusted odds ratios for AMA and young women with placenta previa were 8.8 (6.6-11.6) and 11.7 (9.7-14.1) in preterm birth <37 weeks, 4.0 (3.0-5.3) and 4.9 (4.1-5.9) in neonatal intensive care unit (NICU) admission, 4.0 (2.8-5.7) and 5.9 (4.7-7.4) low birth weight <2500 g, 2.7 (1.5-4.9) and 3.3 (2.2-5.0) in low Apgar score at 5 min. The joint effects of maternal age and placenta previa on the risk of adverse maternal and neonatal outcomes were non-significant. CONCLUSIONS: The risk of adverse maternal and neonatal outcomes for women with placenta previa was not substantially affected by maternal age if their different risk profiles were taken into account.

Five indicators were developed to assess the quality of reviews on preventive interventions.

OBJECTIVES: The objective of the study was to develop quality indicators for preventive effectiveness and to evaluate their use with Cochrane Reviews of primary preventive interventions. STUDY DESIGN AND SETTING: Based on the quality of care framework, we searched the literature to develop a set of quality indicators. Two authors applied the quality indicators independently to a sample of Cochrane systematic reviews of primary prevention. RESULTS: Five quality indicators were developed: sample size, directness of evidence, adherence, harm, and costs. We applied the quality indicators to a random sample of 84 of a total of 264 Cochrane reviews of primary preventive interventions. Only 70% reviews (n = 59) complied with the indicator sample size, whereas 61% (n = 51) complied with directness of the outcome, 48% (n = 40) with adherence, 76% (n = 64) with harm, and 46% (n = 39) with the indicator cost. CONCLUSION: Applying the five quality indicators is feasible. The quality of evidence in reviews of primary prevention can be substantially improved. Trialists and review authors should provide more information especially on adherence, costs, and indirectness of the outcome. Methodological research is needed on how to incorporate cost information in systematic reviews and how to better deal with indirectness.