Multiple Pregnancy: Epidemiology and Association with Maternal and Perinatal Morbidity

Abstract

Twin pregnancy accounts for 2 to 4% of total births, with a prevalence ranging from 0.9 to 2.4% in Brazil. It is associated with worse maternal and perinatal outcomes. Many conditions, such as severe maternal morbidity (SMM) (potentially life-threatening conditions and maternal near-miss) and neonatal near-miss (NNM) still have not been properly investigated in the literature. The difficulty in determining the conditions associated with twin pregnancy probably lies in its relatively low occurrence and the need for larger population studies. The use of the whole population and of databases from large multicenter studies, therefore, may provide unprecedented results. Since it is a rare condition, it is more easily evaluated using vital statistics from birth registries. Therefore, we have performed a literature review to identify the characteristics of twin pregnancy in Brazil and worldwide. Twin pregnancy has consistently been associated with SMM, maternal near-miss (MNM) and perinatal morbidity, with still worse results for the second twin, possibly due to some characteristics of the delivery, including safety and availability of appropriate obstetric care to women at a high risk of perinatal complications.

Twin Births In The Pelotas (Brazil) 2004 And 2015 Birth Cohorts 

“…Older maternal age, together with genetic background and ethnicity, are known factors for multiple pregnancies. (1,20,30,34) As for income, the current nding is consistent with the results of previous analyses in this cohort. Eighteen mothers in 2015 gave birth to 23 newborns conceived by assisted reproduction procedures (in vitro fertilization in 70.6% of the cases).…”

“…Twin births represent 2-4% of pregnancies in the world. (1) In recent decades, due to the growing popularity of assisted reproduction techniques such as in vitro fertilization and intrauterine insemination, there has been an increase in the number of multiple pregnancies, especially in developed countries. (2) In the United States, for example, the twinning rate increased 78% in the last 30 years.…”

“…(15)(16)(17)(18) There are still few studies on the epidemiology of twin pregnancies and twin births in Brazil. (4,8,(19)(20)(21)(22) Thus, based on data from the 2004 and 2015 Pelotas Birth Cohorts, this study aimed to describe the prevalence of multiple pregnancies according to maternal characteristics and to compare rst-and second-born twins from the same cohort to each other and to newborns from singleton pregnancies, according to the incidence of unfavorable perinatal outcomes and infant mortality rate (IMR). The use of two populationbased birth cohorts from the same city, eleven years apart, with data collected for each twin separately at the time of birth, allows to estimate change in twin births prevalence and to assess difference of risk according to birth order.…”

Fatores associados ao near miss neonatal no Brasil

“…There was an approximately three times greater risk of neonatal near miss for twin pregnancies in this study. This result reveals that twin birth – a rare condition that presents several peculiarities and difficulties, not only in clinical management, but also in the scientific approach – is still considered a challenge for the health service and for investigations on greater maternal and perinatal risks 28 . It is worth mentioning that twin pregnancy increases the perinatal mortality rate by two to three times, mainly due to premature birth, intrauterine growth restriction, low birth weight and intrapartum anoxia 29 , 30 .…”

“…Houve um risco aproximadamente três vezes maior de near miss neonatal para gestação gemelar neste estudo. Tal resultado revela que o parto gemelar – condição rara que apresenta diversas particularidades e dificuldades, não apenas no manejo clínico, mas também na abordagem científica – ainda é considerado um desafio para o serviço de saúde e para as investigações sobre maiores riscos maternos e perinatais 28 . Vale destacar que a gestação gemelar aumenta a taxa de mortalidade perinatal de duas a três vezes, principalmente devido ao nascimento prematuro, à restrição de crescimento intrauterino, ao baixo peso ao nascer e à anóxia intraparto 29 , 30 .…”