BACKGROUND Across the developed world couples are postponing parenthood. This
review assesses the consequences of delayed family formation from a demographic and …

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 …

STUDY QUESTION How many twins are born in human populations and how has this
changed over recent decades? SUMMARY ANSWER Since the 1980s, the global twinning …

Background The advent of fertility treatments has led to an increase in the rate of multiple
births in the United States. However, the trends in and magnitude of the contribution of …

Background Twin pregnancy was associated with significantly higher rates of adverse
neonatal and perinatal outcomes, especially for the second twin. In addition, the maternal …

Background Until now, little was known about the variation in incidence of twin births across
developing countries, because national representative data was lacking. This study provides …

Background & Aims: There is growing evidence that the interplay of genetic susceptibility
and environmental factors leads to primary biliary cirrhosis (PBC). In particular, family …

Analyzing the savings behavior of a large sample of identical and fraternal twins, we find that
genetic differences explain about 33 percent of the variation in savings propensities across …

OBJECTIVE: To evaluate maternal complications (potentially life-threatening conditions,
maternal near miss, and maternal death) that are mutually exclusive and severe maternal …

Monozygotic (MZ) twins are considered being genetically identical, therefore they cannot be
differentiated using standard forensic DNA testing. Here we describe how identification of …