Prevalência de nascimentos gemelares em Pelotas, Rio Grande do Sul, Brasil / Prevalence of twin births in Pelotas, in the State of Rio Grande do Sul, Brazil

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 8,95ë (monozigóticos=2,20ë e dizigóticos=6,76ë ). A taxa de triplos ficou em 0,07ë . 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.

OBJECTIVES: to evaluate the prevalence of twin births in Pelotas, Rio Grande do Sul, Brazil, during three periods, and the influence of a number of factors on this occurrence. METHODS: a cross-cutting (multiple time series) study was carried out, using the database of the Congenital Defect Monitoring Program, which registers all of the births occurring in the five hospitals of the city of Pelotas, for the years 1993, 1997 and 2003. RESULTS: the mean prevalence of twin births per thousand births (ë )t was 8.95ë (monozygotic=2.20ë and dizygotic=6.76ë ). The prevalence of triplets was 0.07ë . The total prevalence for twin births, in the case of both monozygotic and dizygotic twins rose over the period studied. The mean age of the mother (27.53 years) and the order in the series of gestations (2.35) were significantly higher in cases of twin births than in cases of the birth of a single infant (26.03 years and 2.14 respectively). CONCLUSIONS: mothers aged >30 years were responsible for the increase in the prevalence of twin births in Pelotas. The higher mean position in a sequence of gestations among mothers of twins ruled out the significance of the use of fertility treatment techniques.

Prevalence and associated factors of discordant twins in Siriraj Hospital.

OBJECTIVES: To determine the prevalence of discordant twins in Siriraj Hospital and to evaluate associated factors. DESIGN: Cross-sectional study. SETTING: Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University. SUBJECTS: A total of 150 women with twin pregnancy, > or = 28 weeks of gestation, who had deliveries of both live twins at Siriraj Hospital from 2003 to 2004. METHOD: A review of medical records was conducted. Discordance was defined as > or = 20% difference in birth weight. Prevalence of discordance was calculated and associated risk factors were evaluated. RESULTS: Discordance was found in 35 cases; therefore, the prevalence was 23.3%. No significant association was found between discordance and various factors, including maternal age, maternal complications, parity, pregnant by assisted reproduction, gestational age at first diagnosis, chorionicity. However, discordant twins delivered at earlier gestational age compared to concordant twins (34.9 +/- 3.2 and 36.2 +/- 2.4 weeks, p = 0.037). Infants of discordant pairs were more likely to be admitted to the NICU than those of concordant pairs (17.1% and 3.9%, p < 0.001, both larger and smaller infants). Other neonatal morbidities were not significantly different. CONCLUSION: Discordance twin was found in 23.3% of the cases. No significant associated risk factor was found. Infants of discordant pairs were more likely to be admitted to the NICU than those of concordant pairs.

Impact of mode of delivery on perinatal mortality in twin pregnancy

During the one year period from 1st January 1993 to 31st December 1993, forty twins deliveries occurred at Obstetric Unit-I, Services Hospital/Allama Iqbal Medical College, Lahore. The perinatal mortality rate was 237.5 per thousand total births [adjusted rate was 227.84]. Sixteen twin pairs were born at less than 37 weeks and 24 at 37 or more weeks of gestation. Perinatal mortality for babies weighing less than 1500gm and at 32 weeks or less, was found to be 1000 and 900 per thousand total births respectively irrespective of method of delivery. The most common cause of early neonatal death in this study was immaturity [63.52 percent] rather than intrapartum problems. Abnormal presentation was found in more than half of twin gestation and the most frequent abnormality was breech presentation involving one or both twins [33.75 percent]. Delivery of both twins by Caesarean section was conducted in 42.5 percent cases and in 55 percent of cases both twins were delivered by vaginal route. In 2.5 percent of cases twin A was delivered by vaginal route and twin B by abdominal route