title: Causes of delivery and outcomes of very preterm twins stratified to zygosity.
abstract: The increasing rates of preterm birth among twins implicate that solid data on associated risks and outcomes are required. Assessment of zygosity is often based on clinical criteria (evaluation of placenta; same gender, birth weight discordance as surrogate criteria for monochorionic/monozygotic twins). The aim of this study was to compare clinical versus genetic assessment of zygosity and to compare causes of preterm delivery as well as outcome data of very-low-birth-weight (VLBW; birth weight <1,500 g) twins stratified to zygosity. In a multicenter study, we selected n=176 sets of same gender twins and determined zygosity genetically. In a subgroup of 123 sets of twins, the attending physicians at the study centers were asked to document the parameter 'zygosity' (monozygotic/dizygotic) on the basis of their clinical judgment. Concordance between genetic and clinical assessment was 62.7% for monozygotic twins and 88.9% for dizygotic twins, respectively. Outcome parameters (death, BPD, ROP, NEC, IVH) were comparable in both groups. Genetically dizygotic twins were significantly more often born due to intrauterine infection (33% vs. 20% in monozygotic twins, p<.01) and antenatal antibiotics were more frequently given to mothers of dizygotic twins (62% vs. 47% in monozygotic twins, p<.01). Obstetric complications such as twin-twin-transfusion-syndrome were only seen in monozygotic twins as expected. The unexpected increase of antenatal antibiotic treatment and birth due to intrauterine infection in dizygotic twins should be confirmed in additional VLBW twin-cohorts.
authors.affiliation: Department of Pediatrics, University Hospital of Schleswig-Holstein, Luebeck, Germany. uni@dr-spiegler.de
authors.forename: Juliane
authors.initials: J
authors.lastname: Spiegler
authors.forename: Christoph
authors.initials: C
authors.lastname: Härtel
authors.forename: Lena
authors.initials: L
authors.lastname: Schulz
authors.forename: Nicole
authors.initials: N
authors.lastname: von Wurmb-Schwark
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoehn
authors.forename: Angela
authors.initials: A
authors.lastname: Kribs
authors.forename: Helmut
authors.initials: H
authors.lastname: Küster
authors.forename: Jens
authors.initials: J
authors.lastname: Siegel
authors.forename: Christian
authors.initials: C
authors.lastname: Wieg
authors.forename: Jan
authors.initials: J
authors.lastname: Weichert
authors.forename: Egbert
authors.initials: E
authors.lastname: Herting
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Göpel
mesh_terms: D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000209:etiology*; D012307:Risk Factors; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic