Maternal age and adverse perinatal outcomes in a birth cohort (BRISA) from a Northeastern Brazilian city

PURPOSE:To verify the existence of associations between different maternal ages and the perinatal outcomes of preterm birth and intrauterine growth restriction in the city of São Luís, Maranhão, Northeastern Brazil.METHODS:A cross-sectional study using a sample of 5,063 hospital births was conducted in São Luís, from January to December 2010. The participants comprise the birth cohort for the study "Etiological factors of preterm birth and consequences of perinatal factors for infant health: birth cohorts from two Brazilian cities" (BRISA). Frequencies and 95% confidence intervals were used to describe the results. Multiple logistic regression models were applied to assess the adjusted odds ratio (OR) of maternal age associated with the following outcomes: preterm birth and intrauterine growth restriction.RESULTS:The percentage of early teenage pregnancy (12–15 years old) was 2.2%, and of late (16–19 years old) was 16.4%, while pregnancy at an advanced maternal age (>35 years) was 5.9%. Multivariate analyses showed a statistically significant increase in preterm births among females aged 12–15 years old (OR=1.6; p=0.04) compared with those aged 20–35 years. There was also a higher rate in preterm births among females aged 16–19 years old (OR=1.3; p=0.01). Among those with advanced maternal age (>35 years old), the increase in the prevalence of preterm birth had only borderline statistical significance (OR=1.4; p=0.05). There was no statistically significant association between maternal age and increased prevalence of intrauterine growth restriction.

Maternal age and Down syndrome in Southeastern Brazil

The proportion of maternal-age-independent patients estimated among 200 Brazilian Down syndrome children (59.6%) was significantly larger than that of maternal-age-dependent cases (40.4%). The latter proportion is the smallest observed in pertinent literature and due basically to the low mean maternal age of the population analyzed. Based on the remarkable correlation (r = 0.95) between the proportion of maternal-age-dependent patients and the mean maternal age of the general population, a simple predictive equation to estimate the proportion of maternal-age-dependent Down syndrome patients based on the mean maternal age of the general population is suggested in situations where reliable data on the incidence of this syndrome according to maternal age is not available.

Are birth weight and maternal smoking during pregnancy associated with malnutrition and excess weight among school age children?

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5³BMIand normal, and children with BMI ³P85 to be overweight. We evaluated the association of these nutritional disorders with birth factors (infant weight, sex, preterm delivery, number of pregnancies, maternal smoking during pregnancy, marital status, and schooling) and type of school using nominal logistic regression. A total of 2797 schoolchildren were evaluated. There was a significant prevalence of malnutrition (9.5%) and excess weight already tended to increase (15.7%), while 6.4% of the children were obese. Excess weight was more prevalent among children attending private schools (odds ratio, OR = 2.27) and firstborn children (OR = 1.69). Maternal smoking during pregnancy protected against malnutrition (OR = 0.56), while children with lower birth weight were at higher risk for malnutrition (OR = 4.23). We conclude that a nutritional transition was under way while malnutrition was still present, but excess weight and related factors were already emerging.

Infant mortality: comparison between two birth cohorts from Southeast and Northeast, Brazil

OBJECTIVE: To obtain population estimates and profile risk factors for infant mortality in two birth cohorts and compare them among cities of different regions in Brazil. METHODS: In Ribeirão Preto, southeast Brazil, infant mortality was determined in a third of hospital live births (2,846 singleton deliveries) in 1994. In São Luís, northeast Brazil, data were obtained using systematic sampling of births stratified by maternity unit (2,443 singleton deliveries) in 1997-1998. Mothers answered standardized questionnaires shortly after delivery and information on infant deaths was retrieved from hospitals, registries and the States Health Secretarys' Office. The relative risk (RR) was estimated by Poisson regression. RESULTS: In São Luís, the infant mortality rate was 26.6/1,000 live births, the neonatal mortality rate was 18.4/1,000 and the post-neonatal mortality rate was 8.2/1,000, all higher than those observed in Ribeirão Preto (16.9, 10.9 and 6.0 per 1,000, respectively). Adjusted analysis revealed that previous stillbirths (RR=3.67 vs 4.13) and maternal age <18 years (RR=2.62 vs 2.59) were risk factors for infant mortality in the two cities. Inadequate prenatal care (RR=2.00) and male sex (RR=1.79) were risk factors in São Luís only, and a dwelling with 5 or more residents was a protective factor (RR=0.53). In Ribeirão Preto, maternal smoking was associated with infant mortality (RR=2.64). CONCLUSIONS: In addition to socioeconomic inequalities, differences in access to and quality of medical care between cities had an impact on infant mortality rates.

Family occurrence of schistosomal hepatosplenomegaly and maternal effect

In this paper we present a study of members of 265 nuclear families, aged six or more. This study is based of family heredograms, and takes into account the clinical form ofschistosomiasis observed before treatment with oxamniquine. The probability of occurrence of two or more cases ofhepatosplenomegaly is low, notwithstanding the fact that it was observed in 38 families. Even less frequent is the occurrence of three or more cases observed in 17 families (P=0.002). The concentration of the hepatosplenic form was higher among siblings than it was among mothers and children, or fathers and children. It was found to be not significant between husband (father) and wife (mother). These observations reinforce the evidence for the presence of a genetic component in susceptibility to the hepatosplenic form of the disease. In cases in which the mother was hepatosplenic there was a higher incidence of hepatosplenic children; the relative risk was a least five times higher than in those in which the father was the affected member (the maternal effect). In cases where both members were affected by the hepatointestinal form, the risk to the filial generation was similar to that of the population in general. Thus, in the process towards severe forms of Schistosomiasis mansoni, pre and post natal factors might be involved.

Congenital and maternal syphilis in the capital of Brazil

INTRODUCTION: ​This study aimed to describe the epidemiology of congenital and maternal syphilis in the Brazilian Federal District in 2010. ​ METHODS: ​A retrospective descriptive study was conducted on the basis of the cases recorded in the System of Notifiable Disease Information. RESULTS: ​The study population comprised 133 cases of congenital syphilis; of these, 116 (52.6%) mothers received prenatal care, and 70 (60.4%) were diagnosed with syphilis during pregnancy. Only 1 mother was adequately treated, and 100 (75.2%) of the pregnant women's partners did not undergo treatment for syphilis. ​ CONCLUSIONS: Although mothers attended prenatal care, not all were diagnosed during pregnancy or received adequate treatment for syphilis, as their partners did not undergo treatment for syphilis.

Multiple dormancy and maternal effect on Miconia ferruginata (Melastomataceae) seed germination, Serra de Caldas Novas, Goiás, Brazil

Species with mostly asexual reproduction are interesting subjects for germination studies since variation would be more easily linked to environmental factors. Miconia ferruginata DC. is an apomictic treelet in Brazilian cerrado areas on rocky outcrops. Germination of seeds collected from individuals occurring in the Serra de Caldas Novas State Park, Goiás, was studied in three experiments under controlled conditions. Germination characteristics differed among individuals and were correlated with altitude and soil Al content. Seeds from plants growing at lower altitudes, with lower soil aluminium content, presented malformed seeds with absence of embryo which rendered lower, but better synchronized germination. The nested analysis showed that from the total variance, 78.14% for germinability, 54.56% for uncertainty of the germination process, and 68.30% for the quantity of seeds without embryo was attributed to the altitudinal effect. Individuals nested within altitude contributed up to 16.93% for the total variance. It means that there is low variability among individuals of the same altitude and high variability among individuals from different points of the slope, making clear that for the studied population the environmental effect is stronger than the genetic component to determine the seed quality. The testa of the seeds provides a mechanical dormancy which seems to be associated also with phenolic compounds, which help to disperse germination through time. Photoblastism was also registered for seeds of this species.

Calculation of breed direct and maternal genetic fractions and breed specific direct and maternal heterozygosity for crossbreeding data

Teaching, research, and herd breeding applications may require calculation of breed additive contributions for direct and maternal genetic effects and fractions of heterozygosity associated with breed specific direct and maternal heterosis effects. These coefficients can be obtained from the first NB rows of a pseudo numerator relationship matrix where the first NB rows represent fractional contributions by breed to each animal or group representing a specific breed cross. The table begins with an NB x NB identity matrix representing pure breeds. Initial animals or representative crosses must be purebreds or two-breed crosses. Parents of initial purebreds are represented by the corresponding column and initial two-breed cross progeny by the two corresponding columns of the identity matrix. After that, usual rules are used to calculate the NB column entries corresponding to breeds for each animal. The NB entries are fractions of genes expected to be contributed by each of the pure breeds and correspond to the breed additive direct fractions. Entries in the column corresponding to the dam represent breed additive maternal fractions. Breed specific direct heterozygosity coefficients are entries of an NB x NB matrix formed by the outer product of the two NB by 1 columns associated with sire and dam of the animal. One minus sum of the diagonals represents total direct heterozygosity. Similarly, the NB x NB matrix formed by the outer product of columns associated with sire of dam and dam of dam contains breed specific maternal heterozygosity coefficients. These steps can be programmed to create covariates to merge with data. If X represents these coefficients for all unique breed crosses, then the reduced row echelon form function of MATLAB or SAS can be used on X to determine estimable functions of additive breed direct and maternal effects and breed specific direct and maternal heterosis effects

Risk factors for perinatal mortality in an urban area of Southern Brazil, 1993

INTRODUCTION: Although there was a considerable reduction in infant mortality in Pelotas, Rio Grande do Sul in the last decade, its perinatal causes were reduced only by 28%. The associated factors of these causes were analised. MATERIAL AND METHOD: All hospital births and perinatal deaths were assessed by daily visits to all the maternity hospitals in the city, throughout 1993 and including the first week of 1994. RESULTS: The perinatal mortality rate was 22.1 per thousand births. The multivariate analysis showed the following risk factors: low socioeconomic level, male sex and maternal age above 35 years . Among multigravidae women, the fetal mortality rate was significantly increased for mothers with a previously low birthweight and a previous stillbirth. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight. CONCLUSIONS: Main risk factors for perinatal mortality: low socioeconomic level, maternal age above 35 years and male sex. For early neonatal mortality the risk was significantly increased by a smaller number of antenatal visits than 5 and low birthweight.

Which factors could explain the low birth weight paradox?

OBJECTIVE: Low birth weight children are unusual among well-off families. However, in Brazil, low birth weight rate was higher in a more developed city than in a less developed one. The study objective was to find out the reasons to explain this paradox. METHODS: A study was carried out in two municipalities, Ribeirão Preto (Southeastern Brazil) and São Luís (Northeastern Brazil), which low birth weight rates were 10.7% and 7.6% respectively. Data from two birth cohorts were analyzed: 2,839 newborns in Ribeirão Preto in 1994 and 2,439 births in São Luís in 1997-1998. Multiple logistic regression analysis was performed, adjusted for confounders. RESULTS: Low birth weight risk factors in São Luís were primiparity, maternal smoking and maternal age less than 18 years. In Ribeirão Preto, the associated variables were family income between one and three minimum wages, maternal age less than 18 and equal to or more than 35 years, maternal smoking and cesarean section. In a combined model including both cohorts, Ribeirão Preto presented a 45% higher risk of low birth weight than São Luís. When adjusted for maternal smoking habit, the excess risk for low birth weight in Ribeirão Preto compared to São Luís was reduced by 49%, but the confidence interval was marginally significant. Differences in cesarean section rates between both cities contributed to partially explain the paradox. CONCLUSIONS: Maternal smoking was the most important risk factor for explaining the difference in low birth weight between both cities. The other factors contributed little to explain the difference in low birth weight rates.

Risk factors for sudden infant death syndrome in a developing country

OBJECTIVE: To analyze whether previously identified risk factors for sudden death syndrome have a significant impact in a developing country. METHODS: Retrospective longitudinal case-control study carried out in Porto Alegre, Southern Brazil. Cases (N=39) were infants born between 1996 and 2000 who died suddenly and unexpectedly at home during sleep and were diagnosed with sudden death syndrome. Controls (N=117) were infants matched by age and sex who died in hospitals due to other conditions. Data were collected from postmortem examination records and questionnaires answers. A conditional logistic model was used to identify factors associated with the outcome. RESULTS: Mean age at death of cases was 3.2 months. The frequencies of infants regarding gestational age, breastfeeding and regular medical visits were similar in both groups. Sleeping position for most cases and controls was the lateral one. Supine sleeping position was found for few infants in both groups. Maternal variables, age below 20 years (OR=2, 95% CI: 1.1; 5.1) and smoking of more than 10 cigarettes per day during pregnancy (OR=3, 95% CI: 1.3; 6.4), significantly increased the risk for the syndrome. Socioeconomic characteristics were similar in both groups and did not affect risk. CONCLUSIONS: Infant-maternal and socioeconomic profiles of cases in a developing country closely resembled the profile described in the literature, and risk factors were similar as well. However, individual characteristics were identified as risks in the population studied, such as smoking during pregnancy and maternal age below 20 years.

Intrauterine ductus arteriosus constriction: analysis of a historic cohort of 20 cases

OBJECTIVE: To describe the relative incidence, presentation, and evolvement of fetuses with early ductus constriction. METHODS: Twenty fetal echocardiograms indicating ductus constriction were reviewed in a population of 7000 pregnants. RESULTS: The cases were divided into group A (related to maternal use of cyclooxygenase inhibitors [n=7] and group B (idiopathics [n=13]). Mean gestational age was 32.5±3.1 (27-38) weeks and maternal age was 28.2±8.5 (17-42) years. Mean systolic velocity in the ductus was 2.22±0.34 (1.66-2.81) m/s, diastolic velocity 0.79±0.28 (0.45-1.5) m/s, and pulsatility index 1.33±0.36 (0.52-1.83). Two cases of ductal occlusion were noted. In 65% of the cases, an increase occurred in the right cavities; in 90% of the cases, tricuspid or pulmonary regurgitation, or both, occurred, with functional pulmonary atresia in 1 case. Diastolic velocity was greater in group A (1.13±0.33) than in group B (0.68±0.15) (P=0.008). The other data were similar in the 2 groups. The evolvement was not favorable in 4 patients from group B, including 1 death and 2 cases of persistent pulmonary hypertension. CONCLUSION: The high incidence of idiopathic constriction of the ductus arteriosus suggests that its diagnosis is underestimated and that many cases of persistence of fetal circulation in newborns may be related to constriction of the ductus arteriosus not diagnosed during intrauterine life. Group B had a lower severity but a risk of an unfavorable evolvement, suggesting a distinct alteration.

Effect of the exposure to maternal smoking during pregnancy and childhood on the body mass index until adolescence

OBJECTIVE Investigate the effect of exposure to smoking during pregnancy and early childhood on changes in the body mass index (BMI) from birth to adolescence.METHODS A population-based cohort of children (0-5 years old) from Cuiabá, Midwest Brazil, was assessed in 1999-2000 (n = 2,405). Between 2009 and 2011, the cohort was re-evaluated. Information about birth weight was obtained from medical records, and exposure to smoking during pregnancy and childhood was assessed at the first interview. Linear mixed effects models were used to estimate the association between exposure to maternal smoking during pregnancy and preschool age, and the body mass index of children at birth, childhood and adolescence.RESULTS Only 11.3% of the mothers reported smoking during pregnancy, but most of them (78.2%) also smoked during early childhood. Among mothers who smoked only during pregnancy (n = 59), 97.7% had smoked only in the first trimester. The changes in body mass index at birth and in childhood were similar for children exposed and those not exposed to maternal smoking. However, from childhood to adolescence the rate of change in the body mass index was higher among those exposed only during pregnancy than among those who were not exposed.CONCLUSIONS Exposure to smoking only during pregnancy, especially in the first trimester, seems to affect changes in the body mass index until adolescence, supporting guidelines that recommend women of childbearing age to stop smoking.

Subsequent pregnancies: who has them and who wants them? Observations from an urban center in Southern Brazil

Subsequent pregnancies in mothers of a birth cohort from Pelotas, Southern Brazil, were studied in relation to maternal and socio-economic factors. Within about 3 1/2 years of the cohort child's birth, 39% of mothers had experienced at least one further pregnancy. This proportion decreased with increasing maternal age, years of schooling and family income. A U-shaped trend was observed with respect to parity. Mothers who had delivered the cohort child by caesarean section were also less likely to have another pregnancy within that time. Logistic regression analysis showed that each of these factors remained significantly associated with further pregnancies after controlling for the remaining variables. Analysis of the first subsequent pregnancy showed that a high proportion of mothers had not wanted the pregnancy. Unwanted pregnancies were also significantly associated with older women, low educational status, higher parity and low family income.

Mid-upper arm circumference in pregnant women and its relation to birth weight

OBJECTIVE: In order to determine the relationship between some maternal anthropometric indicators and birth weight, crown-heel length and newborn's head circumference, 92 pregnant women were followed through at the prenatal service of hospital in S. Paulo, Brazil. MATERIAL AND METHOD: The following variables were established for the mother: weight, height, mid-upper arm circumference, pre-pregnancy weight, gestational weight gain and Quetelet's index. For the newborn the following variables were recorded: birth weight, crown-heel length, head circumference and gestational age by Dubowitz's method. RESULTS: Significant associations were noted between gestational age and newborn variables. In addition, maternal mid-arm circumference (MUAC) and pre-pregnancy weight were found to be positively correlated to birth weight (r=0.399; r=0.378, respectively). The multivariate linear regression shows that gestational age, mother's arm circumference and pre-pregnancy weight continue to be significant predictors of birth weight. On the other hand, only gestational age and mother's age was associated with crown-heel length. Similarly MUAC was significantly associated with crown-heel length (r= 0.306; P=0.0030). CONCLUSION: Maternal mid-upper arm circumference is a potential indicator of maternal nutritional status. It could be used in association with other anthropometric measurements, instead of pre-pregnancy weight, as an alternative indicator to assess women at risk of poor pregnancy outcome.