Maternal socioeconomic factors and adverse perinatal outcomes in two birth cohorts, 1997/98 and 2010, in São Luís, Brazil

Secular trends and age-period-cohort effect on adverse perinatal outcomes in Hubei, China (2011-2019)

The increasing trend in the incidence of adverse perinatal outcomes is a public health concern globally as well as in China. However, the causes of the increasing trend are not well understood. The present tertiary-hospital-based retrospective study (2011-2019) aims to determine the secular trends and age-period-cohort effect on adverse perinatal outcomes in Hubei, China. The age-standardized incidence rates of adverse perinatal outcomes significantly decreased such as preterm births by 22% [AAPC - 3.4% (95% CI - 7.8, - 1.2)], low birth weight (LBW) by 28.5% [AAPC - 4.7% (95% CI - 6.0, - 3.3)], and fetal distress by 64.2% [AAPC - 14.0% (95% CI - 17.8, - 10.0)] during 2011-2019. Both extremes of maternal age groups (18-20 years and 42-44 years) had a higher risk ratio for adverse perinatal outcomes including preterm birth, perinatal mortality, LBW, low ponderal index (LPI), low Apgar score, and congenital defect compared to the reference age group (30-32 years). A higher risk ratio for perinatal mortality, intrauterine growth restriction (IUGR), and fetal distress and a lower risk ratio for preterm births and LBW were observed in the period 2017-2019. Both the young cohort (1997-1999) and the old cohort (1976-1969) had a higher risk ratio for preterm birth, perinatal mortality, macrosomia, and congenital defect compared to the reference cohort (1982-1984). In conclusion, some of the adverse perinatal outcomes incidence significantly decreased in the last 9 years in Hubei. However, extremes of maternal age groups and both young and old cohorts were associated with a higher risk of preterm birth, perinatal mortality, and congenital defect.

Association between preterm births and socioeconomic development: analysis of national data

Background

The increasing prevalence of preterm birth, which is a global phenomenon, is attributable to the increased medical indications, artificial gestations, and some socioeconomic factors. This study was conducted to identify whether development and equality indices are associated with the incidence of preterm birth, specifically, spontaneous and elective preterm births.

Methods

This retrospective observational study comprised an analysis of data on live births from 2019 in Brazil and on socioeconomic indices that were derived from census information in 2017. Data were summarised using absolute and relative frequencies. Spearman’s correlation was used to determine the correlation between socioeconomic factors and the preterm birth rate. Multiple beta regression analysis was performed to determine the best model of socioeconomic covariates and preterm birth rate. The significance level was set at 5%.

Results

In 2019 in Brazil, the preterm birth rate was 11.03%, of which 58% and 42% were spontaneous and elective deliveries, respectively. For all preterm births, Spearman’s correlation varied from ρ = 0.4 for the Gini Index and ρ =  − 0.24 for illiteracy. The best fit modelled the spontaneous preterm birth fraction as a negative function of the Human Development Index (HDI). The best-fit model considered the expected elective preterm birth fraction as a positive function of the HDI and as a negative function of the Gini Index, which was used as a precision parameter.

Conclusions

We observed a reduction in the fraction of spontaneous preterm births; however, the distribution was not uniform in the territory: higher rates of spontaneous preterm birth were noticed in the north, northeast, and mid-west regions. Thus, areas with lower education levels and inequal income distribution have a higher proportion of spontaneous preterm birth. The fraction of elective preterm birth was positively associated with more advantaged indices of socioeconomic status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14376-2.

[Weight/head circumference ratio at birth for assessing fetal growth]

The scope of this article was to use the weight/head circumference ratio at birth to assess fetal growth. A cross-sectional study was conducted in a birth cohort in the State of Paraíba, Northeast of Brazil, with 726 children born at term and weighing 2,500 grams or more. The anthropometric measurements, sociodemographic characteristics, gestational care and type of delivery were collected in the first 24 hours after birth of infants were assessed. Infants were classified as proportionate (weight/head circumference ratio ≥0.87) versus disproportionate (<0.87). Lower mean weight/head circumference ratio was identified in newborns of lower gestational age, with lower birth weight, female, from families not benefiting from the Bolsa Família Program, of mothers who did not take folic acid during pregnancy and were born by cesarean section. Mean weight, length, and head circumference were lower among infants with disproportionate weight/head circumference ratio, independently of sex. Weight/head circumference ratio is an important indicator of fetal growth.

Adverse pregnancy outcomes and occlusal traits in the primary dentition: A prospective cohort (BRISA)

OBJECTIVES

This study aimed to analyse the relationship between adverse pregnancy outcomes (APO) and occlusal traits in the primary dentition, checking for different mediation paths.

SETTING AND SAMPLE POPULATION

Children evaluated at birth (T1), between 12 and 24 months (T2), and between 24 and 36 months (T3) were included. Two hundred and seventeen children who participated in T1 and T2 were randomly selected to perform the occlusion examination.

MATERIALS AND METHODS

This is a prospective cohort study (BRISA). The theoretical model was tested by structural equation modelling (SEM), estimating standardized coefficients (Coeff.) (α = 0.05). The primary exposure was APO-a latent variable manifested from three health problems at birth: low birthweight (LBW), pre-term birth (PTB) and intrauterine growth restriction (IUGR), evaluated in T1. The outcomes were four different occlusal traits assessed in T3: overjet, anterior and posterior crossbite, and crowding. Each outcome's direct and indirect effects were tested, mediated by growth, breathing, breastfeeding, and pacifier use.

RESULTS

There was no direct association between APO and any of the outcomes: overjet (Coeff. = -0.163, P = .241), anterior crossbite (Coeff. = -0.696, P = .065), posterior crossbite (Coeff. = -0.087, P = .589) and crowding (Coeff. = 0.400, P = .423). The indirect (total and specifics) effects tested also showed no association (P > .05). However, APO was associated with lower child growth in all models; breastfeeding was associated with higher child growth in all models, and pacifier use was associated with overjet (Coeff. = 0.184, P < .001) and posterior crossbite (Coeff. = 0.373, P = .011).

CONCLUSION

APO was not a risk factor for overjet, crossbite and crowding in an early stage of the primary dentition by direct and indirect pathways. However, growth has been lower in children with APO and higher in children breastfed. Also, the harmful effects of using a pacifier in dental occlusion are highlighted.

Joint attention abilities in Brazilian preterm and full-term infants

Joint attention abilities of preterm and full-term Brazilian infants were assessed at 12- and 18-months, age corrected for prematurity. Results showed that preterm infants displayed significantly lower levels of correct responses to others' bids for joint attention at both time-points, compared to full-term infants. Both groups improved their responding to joint attention from 12 to 18 months of age. Contrastingly, prematurity did not impact infants' initiating joint attention behaviors, which remained stable over time for both groups. Findings were discussed in terms of the specific mental processes involved in distinct behavioural dimensions of joint attention.

Periodontopathogenic microbiota, infectious mechanisms and preterm birth: analysis with structural equations (cohort-BRISA)

PURPOSE

The association between periodontopathogenic microbiota and preterm birth (PTB) has been overly studied. However, the biological mechanisms involved are little known. The objective is to evaluate the effect of periodontopathogenic bacteria burden (PBB), periodontal disease and other infections during pregnancy on preterm birth (PTB), through Structural Equation Modeling.

METHODS

This was a case-control study nested in a prospective cohort called BRISA, including 330 pregnant women, 110 cases and 220 controls. This study included the following variables: cytokines interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), periodontal disease, PBB, age, socioeconomic status (SES), systemic infections and PTB. The correlations between variables were analyzed using Standardized Coefficient (SC).

RESULTS

Greater PBB interfered positively with the occurrence of periodontal disease (SC: 0.027; p: 0.011), but these were not associated with the cytokines studied, nor with PTB. The lower serum levels of IL-10 (SC - 0.330; p 0.022) and TGF-β (SC - 0.612; p  < 0.001), and the presence of other systemic infections during pregnancy (SC 0.159; 0.049) explained the higher occurrence of PTB.

CONCLUSION

It is possible that only the more severe periodontal disease and other systemic infections are capable of altering the cascade of cytokines regulating the inflammatory process and have an effect on the occurrence of PTB.