Twinning rate in a sample from a Brazilian hospital with a high standard of reproductive care

Modelling for the inheritance of multiple births and fertility in endangered equids: Determining risk factors and genetic parameters in donkeys (Equus asinus)

Multiple births or twinning in equids are dangerous, undesirable situations that compromise the life of the dam and resulting offspring. However, embryo vitrification and freezing techniques take advantage of individuals whose multiple ovulations allow flushing more fertilised embryos from the oviduct to be collected, increasing the productivity and profitability of reproductive techniques. Embryo preservation is especially important in highly endangered populations such as certain donkey (Equus asinus) breeds; for which conventional reproductive techniques have previously been deemed inefficient. For instance, becoming an effective alternative to artificial insemination with frozen semen to preserve the individuals' genetic material. The objective of this study was to examine the historical foaling records of Andalusian donkeys to estimate prevalence, risk factors, phenotypic and genetic parameters for multiple births, assessing the cumulative foal number born per animal, maximum foal number per birth and multiple birth number per animal. We designed a Bayesian General Animal Mixed Model with single records considering the 'fixed' effects of birth year, birth season, birth month, sex, farm, location, and husbandry system. Age was considered and included as a linear and quadratic covariate. Gibbs sampling reported heritability estimates ranging from 0.18 ± 0.101 to 0.24 ± 0.078. Genetic and phenotypic correlations ranged from 0.496 ± 0.298 to 0.846 ± 0.152 and 0.206 ± 0.063 to 0.607 ± 0.054, respectively. Predicted breeding values obtained enable the potential selection against/for these traits, offering a new perspective for donkey breeding and conservation.

Twin Pregnancy in Brazil: A Profile Analysis Exploring Population Information from the National Birth E-Registry on Live Births

Birth records as SINASC (Brazilian Live Birth Information System) are highlighted in uncommon conditions such as twin pregnancy whose prevalence rarely exceeds 2 to 3% of the total number of births. The objective of this study was to assess the prevalence of twin pregnancies in Brazil and their maternal and perinatal characteristics using data from the national birth e-Registry. All births in Brazil from 2011 to 2014 were assessed. Prevalence of twin pregnancies per region was assessed and correlated with the Human Development Index (HDI). Sociodemographic and obstetric factors and main perinatal outcomes were assessed for the first and second twin, in comparison to singletons, and the second twin compared to the first twin, with PR and 95%CI. A multiple logistic regression analysis was conducted to identify factors independently associated with a low 5-minute Apgar score in twin pregnancies. Twin pregnancy occurred in 1.13% in Brazil, with a higher prevalence in regions with a higher HDI. It was associated with a complete higher level of education (22.9% versus 16.3% for singles) and maternal age > 35 years (17.5% versus 11.4% for singles). Preterm birth <32 weeks (prevalence ratio-PR 12.13 [11.93 – 12.33]), low birth weight (PR 17.8 [17.6-18.0] for the first and PR 20.1 [19.8-20.3] for the second twin), and low Apgar score (PR 2.9 [2.8-3.0] for the first and PR 2.7 [2.6-2.8] for the second twin) were the most important perinatal outcomes associated with twin pregnancies. A 5-minute Apgar score < 7 among twins was associated with inadequate prenatal care, extreme preterm birth, vaginal delivery, intrapartum cesarean, and combined delivery. Twin pregnancy in Brazil is associated with worse perinatal outcomes, especially for the second twin.

Twin Peaks: A spatial and temporal study of twinning rates in Brazil

Twin births are an important public health issue due to health complications for both mother and children. While it is known that contemporary factors have drastically changed the epidemiology of twins in certain developed countries, in Brazil, relevant data are still scarce. Thus, we carried out a population-based study of live births in spatial and temporal dimensions using data from Brazil's Live Birth Information System, which covers the entire country. Over 41 million births registered between 2001 and 2014 were classified as singleton, twin or multiple. Twinning rates (TR) averaged 9.41 per 1,000 for the study period and a first-order autoregressive model of time-series analysis revealed a global upward trend over time; however, there were important regional differences. In fact, a Cluster and Outlier Analysis (Anselin Local Moran's I) was performed and identified clusters of high TR in an area stretching from the south of Brazil's Northeast Region to the South Region (Global Moran Index = 0.062, P < 0.001). Spearman's correlation coefficient and a Wilcoxon matched pairs test revealed a positive association between Human Development Index (HDI) and TRs in different scenarios, suggesting that the HDI might be an important indicator of childbearing age and assisted reproduction techniques in Brazil. Furthermore, there was a sharp increase of 26.42% in TR in women aged 45 and over during study period. The upward temporal trend in TRs is in line with recent observations from other countries, while the spatial analysis has revealed two very different realities within the same country. Our approach to TR using HDI as a proxy for underlying socioeconomic changes can be applied to other developing countries with regional inequalities resembling those found in Brazil.

Analysis of Polymorphism rs1042522 in TP53 Gene in the Mothers of Twins and of Singletons: A Population-Based Study in Rio Grande do Sul, Brazil

Although the birth of twins has always attracted attention, there are no known genetic or environmental factors that can determine the birth of monozygotic (MZ) twins. And even for dizygotic (DZ) twins, genetic influences are not completely understood. A previous study from our group has shown that the C allele of polymorphism rs1042522 in the TP53 gene was more frequent in the mothers of twins than in the mothers of singletons in a small village in South Brazil. In order to clarify whether this was an isolated factor, we performed a population-based, observational case-control study. Samples were selected from a state-funded program of paternity investigation. Samples were considered cases when two of the children had the same date of birth, whereas controls were those samples in which at least two children were born in different dates. The first subsequent sample fulfilling control criteria was included after each case. From 2007 to 2013, 32,661 records were searched and 283 (0.9%) twins were found (119 MZ and 164 DZ). Genotypic and allele frequencies were not different between mothers of twins or mothers of singletons. However, mothers of MZ twins showed a higher frequency of GG genotype and lower frequency of the C allele when compared to mothers of DZ twins. Also, the proportion of MZ twins (42%) was higher than usually reported (30%). Finally, the proportion of twins found in this study seems to be more realistic, as this sample was allegedly not from users of assisted reproduction techniques.

Twinning and Multiple Birth Rates According to Maternal Age in the City of São Paulo, Brazil: 2003–2014

The present study investigates the twinning rates in the city of São Paulo, Brazil, during the years 2003–2014. The data were drawn from the Brazilian Health Department database of Sistema de Informações de Nascidos Vivos de São Paulo—SINASC (Live Births Information System of São Paulo). In general, more information is available on the incidence of twinning in developed countries than in developing ones. A total of 24,589 twin deliveries and 736 multiple deliveries were registered in 140 hospitals of São Paulo out of a total of 2,056,016 deliveries during the studied time period. The overall average rates of singleton, twin, and multiple births per 1,000 maternities (‰) were 987.43, 11.96 (dizygotic (DZ) rate was 7.15 and monozygotic (MZ) 4.42), and 0.36, respectively. We further regressed maternal age and historical time period on percentage of singleton, twin, and multiple birth rates. Our results indicated that maternal age strongly positively predicted twin and multiple birth rates, and negatively predicted singleton birth rates. The historical time period also positively, although weakly, predicted twin birth rates, and had no effect on singleton or multiple birth rates. Further, after applying Weinberg's differential method, we computed regressions separately for the estimated frequencies of DZ and MZ twin rates. DZ twinning was strongly positively predicted by maternal age and, to a smaller degree, by time period, while MZ twinning increased marginally only with higher maternal age. Factors such as increasing body mass index or air pollution can lead to the slight historical increase in DZ twinning rates. Importantly, consistent with previous cross-cultural and historical research, our results support the existence of an age-dependent physiological mechanism that leads to a strong increase in twinning and multiple births, but not singleton births, among mothers of higher age categories. From the ultimate perspective, twinning and multiple births in later age can lead to higher individual reproductive success near the end of the reproductive career of the mother.

Perfil das patologias prevalentes na gestação de alto risco em uma maternidade escola de Maceió, Alagoas, Brasil

Objetivos: Descrever o perfil epidemiológico das patologias prevalentes na gestação de alto risco na Maternidade Escola Santa Mônica, município de Maceió, Alagoas. Métodos: Estudo epidemiológico, transversal e retrospectivo, realizado por meio da análise descritiva dos dados de prontuários de gestantes atendidas por ocasião do parto no período de janeiro de 2006 a novembro de 2010. Foram incluídos prontuários das gestantes de alto risco atendidas na maternidade no período estudado e excluídos da pesquisa os prontuários não preenchidos corretamente ou incompletos quanto às patologias prevalentes na gestação de alto risco. O cálculo amostral foi realizado a partir do teste de hipótese para uma proporção, segundo Lwanga e Lemeshow. A coleta de dados foi realizada por meio de preenchimento de formulário contendo informações dos prontuários, desenvolvido para esta pesquisa. As variáveis foram: patologias prevalentes na gestação de alto risco, idade materna, paridade, tipo de parto e tempo de gestação. Resultados: Foram analisados 316 prontuários. O trabalho de parto prematuro foi a patologia mais prevalente, representando 31,4% (98/312; IC95% 26,5 a 36,8) das patologias de alto risco. Em relação à idade materna, 72,7% (227/312; IC95% 67,5 a 77,4) das gestantes eram jovens (<30 anos). Quanto ao número de gestações, as multíparas corresponderam a 52,9% (165/312; IC95% 47,3 a 58,3). Considerando o tipo de parto, 59,0% (184/312; IC95% 53,4 a 64,3) foram cesáreos. Quanto ao tempo de gestação, 47,4% (148/312; IC95% 42,0 a 53,0) foram prematuros. Conclusões: O perfil epidemiológico encontrado foi o trabalho de parto prematuro em gestantes jovens e multíparas que evoluíram para um parto cesariano e pré-termo. 

Chilean School-Age Children Twin Registry: Planning, Sampling and Implications

We describe subject recruitment from the University of Chile School-Age Children Twin Registry (REMEUCHI). The research aim of REMEUCHI is to quantify the impact of genetic and environmental factors on scholastic achievement in a multicausal approach. The Ministry of Education of Chile, in collaboration with the Registry Office, provided the list of possible twin pairs graduated from high school in 2004 in Chile's metropolitan region. From a population of 70,065 school-age children who had graduated from high school, 434 possible twin pairs were analyzed. Of these, 327 were twins reared together (75.3% of the 434 possible twins pairs) and born between 1986 and 1987 in Chile (mean age 18 years), and approximately 8% were not twins despite matches on full name and birth data. The rest of the possible twin pairs were probably twins reared apart, since one member of the pair had moved to study in another region of Chile. Zygosity was determined through questionnaires, maternal reports of twin similarities, and by the hospital records of the twins at the time of birth. Three hundred and twenty-seven pairs were identified, where monozygotic (MZ) and dizygotic (DZ) twins represented 46.8% and 53.2% of pairs, respectively, with a DZ/MZ ratio of 1.14. Considering same-sex MZ pairs, the percentage of female pairs was greater (55.6%) than male pairs (44.4%). When DZ pairs were analyzed, 47.7% were of opposite sex, 20.1% were male pairs and 32.2% female pairs. In Chile, these findings represent a baseline study to contribute to the establishment of a national twin registry in the future.

Prevalência de nascimentos gemelares em Pelotas, Rio Grande do Sul, Brasil

OBJETIVOS: avaliar a prevalência de nascimentos gemelares em Pelotas, RS, em três períodos da última década e a influência de alguns fatores sobre este processo. MÉTODOS: estudo de corte transversal (série temporal), baseado no banco de dados do Programa de Monitorização de Defeitos Congênitos, onde se encontram registrados todos os nascimentos ocorridos nos cinco hospitais da cidade de Pelotas, nos anos de 1993, 1997 e 2003. RESULTADOS: a taxa média de gêmeos por mil nascimentos foi de 8,95‰ (monozigóticos=2,20‰ e dizigóticos=6,76‰ ). A taxa de triplos ficou em 0,07‰ . A taxa total de nascimentos gemelares, assim como de gêmeos monozigóticos e dizigóticos sofreu elevação no período. A média de idade (27,53 anos) e da ordem gestacional (2,35) das mães de gêmeos foi significativamente mais elevada do que das mães de únicos (26,03 anos e 2,14) respectivamente. Verificaram-se números aproximados de partos gemelares e únicos nos diferentes grupos de renda materna analisados. CONCLUSÕES: as mães com idade maior ou igual a 30 anos foram responsáveis pelo aumento da taxa de gêmeos em Pelotas. A média mais elevada de ordem gestacional em mães de gemelares descartou o uso significativo de técnicas de reprodução assistida.

Medida de energia total do leite materno de mães de trigêmeos, gêmeos e filhos únicos

OBJETIVO: Comparar a energia total do leite materno de mães de trigêmeos, gêmeos e filhos únicos. MÉTODOS: Estudo transversal e controlado feito com mães usuárias do banco de leite do Hospital Israelita Albert Einstein. Foram analisadas seis amostras de leite materno de mães de trigêmeos, 13 de gêmeos e 17 de filhos únicos, coletadas sob paramentação, conforme normas técnicas da Rede Brasileira de Bancos de Leite Humano. A análise foi realizada por meio do teste de crematócrito e os resultados submetidos à análise de variância de Kuskal-Wallis. RESULTADOS: A energia total do leite materno de mães de trigêmeos apresentou mediana de calorias maior (651kcal/L), quando comparada à do leite de mães de filhos únicos (560kcal/L) (p<0,05). O leite das mães de gêmeos e o de mães de filhos únicos não foram diferentes. Os trigêmeos apresentaram peso ao nascer menor (mediana 1344g) em relação aos filhos únicos (1975g) (p<0,01). Não foi observada diferença estatística em relação à idade gestacional e à idade materna entre os três grupos de neonatos. CONCLUSÕES: Pode-se concluir que o presente estudo, o primeiro na literatura sobre o tema, apontou para a presença de maior valor de energia total no leite de mães de recém-nascidos trigemelares. Futuros estudos são necessários para elucidar os mecanismos envolvidos nesse achado.

Perinatal mortality 1982-2001 at Vila Central Hospital, Vanuatu

OBJECTIVE

To determine the perinatal mortality at Vila Central Hospital (VCH) and thereby make an estimate of Vanuatu's perinatal mortality.

METHODS

Labour floor and nursery records from VCH, Vanuatu's only tertiary referral hospital, were examined and collated for the period 1982-2001. Death certificate books were also examined. The perinatal mortality rate was calculated as the sum of stillbirths (infants = 20 weeks and/or = 500 g) and neonatal mortality (deaths <28 days). Premature infants were recorded for infants less than 37 weeks gestation and small-for-gestational-age for infants less than 2500 g.

RESULTS

The mean perinatal mortality rate for the period was 27/1000, (range 15-36/1000). The mean stillbirth rate was 15/1000, (range 8-22/1000). The neonatal mortality was 12/1000, (range 4-18/1000). Premature babies accounted for 37/1000 births, (range 11-80/1000). Small-for-gestational-age infants were recorded in 45/1000 births, (range 16-83/1000). The mean twinning rate was 12/1000. Seven spontaneous triplets, two quadruplets and two pairs of siamese twins were born. Sepsis, meconium aspiration and birth asphyxia were the commonest causes of neonatal death.

CONCLUSION

Accurate data collection is difficult in Vanuatu. There is the risk of under-ascertainment however, the figure of 27/1000 represents the current best possible estimate of perinatal mortality at VCH over the last 20 years. VCH is Vanuatu's premier hospital and it is likely that the national figure for perinatal mortality is higher, probably in the range of 37-39/1000. This places Vanuatu's perinatal mortality at a level 30 years or more behind Australia. These figures represent the largest account of hospital based perinatal data collected from any Pacific island nation.

Weight-for-length relationship at birth to predict neonatal diseases

CONTEXT

Intrauterine growth curves are extremely useful for classifying newborn children and predicting neonatal diseases. However, such curves rely on knowledge of the gestational age, which is not always easily obtained. Therefore, the study of other anthropometric measurements and their interrelationship is always desirable, in order to attain such objectives.

OBJECTIVE

To evaluate whether newborns' birth weight and length can identify neonatal diseases, independent of knowledge of the gestational age.

TYPE OF STUDY

Retrospective study.

SETTING

Institute of Teaching and Research of Hospital Israelita Albert Einstein, São Paulo, Brazil.

PARTICIPANTS

During the period from February 1995 to January 1998, 8,397 live newborns were studied in the hospital's maternity ward.

PROCEDURES

The weight and length of live newborns were obtained at birth, thus allowing the analysis of weight-for-length adequacy, i.e. the distribution of birth weight for each class of birth length. These measurements were determined for the first 4,634 live newborns and the 10th and 90th percentiles were established. These parameters were applied to the next 3,763 consecutive newborns of the same population. The relationships between these variables and some neonatal diseases were investigated. The significance level adopted was p<0.05.

MAIN MEASUREMENTS

Birth weight and length, weight-for-length adequacy (10th and 90th percentiles for weight distribution in each 1-cm length class), weight/length index (10th and 90th percentiles of newborn's weight divided by the length) and frequent neonatal diseases in this population.

RESULTS

There was a significant association of adequacy and index with the following affections: asphyxia, jaundice, hypoglycemia, hypomagnesemia, congenital pneumonia, pulmonary hypertension and sepsis. Additionally, there was a relationship between the index and respiratory distress syndrome, transient tachypnea and persistent ductus arteriosus.

CONCLUSIONS

Weight-for-length adequacy and weight/length index alone, without the knowledge of gestational age, were able to identify newborns at risk for some selected neonatal diseases.