title: Preterm delivery and growth restriction in multifetal pregnancies reduced to twins.
abstract: Gestation at delivery, birthweight and pregnancy outcome of surviving fetuses from 127 multifetal pregnancies undergoing embryo reduction to twins were compared to 354 chromosomally normal non-reduced dichorionic twin pregnancies. First-trimester embryo reduction was carried out by intracardiac injection of KCl. In 16 (12.6%) of the 127 multifetal pregnancies reduced to twins, there was miscarriage of both fetuses before 24 weeks of gestation. The median interval between reduction and fetal loss was 5 weeks (range 1-12). In livebirths, the median gestation at delivery was 36 weeks (range 24-41) and the median difference in birthweight from the appropriate mean was -0.94 SD (range -3.89-1.73 SD). Both fetal loss before 24 weeks and the interval between embryo reduction and delivery were significantly associated with the gestation at reduction (r = 0.40, P < 0.001 and r = -0.57, P < 0.001 respectively). In the pregnancies reduced to twins compared to the non-reduced twins, the percentage of miscarriages was higher (12.6 compared to 2.5%; chi 2 = 19.2, P < 0.001), the median gestation at delivery was lower (36 compared to 37 weeks; t = -1.74, P < 0.05), and the median birthweight deficit was greater (-0.94 compared to -0.65 SD: t = -4.1, P < 0.001).
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Sebire
authors.forename: C
authors.initials: C
authors.lastname: Sherod
authors.forename: A
authors.initials: A
authors.lastname: Abbas
authors.forename: R J
authors.initials: RJ
authors.lastname: Snijders
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000022:Abortion, Spontaneous; D001724:Birth Weight; D005260:Female; D005313:Fetal Death; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D011247:Pregnancy; D011256:Pregnancy Outcome; D018607:Pregnancy Reduction, Multifetal; D011272:Pregnancy, Multiple