title: Hypertension in dichorionic twin gestations: how is birthweight affected?
abstract: OBJECTIVE
  To examine the association between hypertension (HTN) and discordant or small for gestational age (SGA) birthweights among dichorionic twin pregnancies.
  
  
  METHODS
  Retrospective cohort of dichorionic twin pregnancies delivered at ≥24 0/7 weeks from 2002 to 2015. Women with HTN in pregnancy (gestational HTN or preeclampsia) and chronic HTN (cHTN) were compared to those with uncomplicated dichorionic pregnancies. Outcomes were any discordance (≥20% difference within each twin pair), discordance with at least one twin also SGA (≥20% discordance with at least one twin also SGA <10th percentile), and SGA alone of one or both twins (<5th and <10th percentile).
  
  
  RESULTS
  474 Dichorionic pregnancies were identified. Women with HTN in pregnancy had an adjusted odds ratio (aOR) of 2.68 (95% CI 1.48-4.87) for any discordance and 2.94 (1.57-5.48) for discordance with at least one twin also SGA. These aORs for women with cHTN were 4.65 (1.39-15.52) and 4.37 (1.21-15.76), respectively. Significant differences were not observed for SGA alone of one or both twins.
  
  
  CONCLUSIONS
  Among dichorionic pregnancies, both women with HTN in pregnancy and cHTN demonstrated increased odds of any discordant growth, as well as discordance with concurrent SGA of at least one twin. Odds of these outcomes were greatest with cHTN.
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Sciences, Division of Maternal-Fetal Medicine, University of California , San Francisco , CA , USA , and.|b Department of Pediatrics , Division of Medical Genetics, University of California , San Francisco , CA , USA.
authors.forename: Teresa N
authors.initials: TN
authors.lastname: Sparks
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Sciences, Division of Maternal-Fetal Medicine, University of California , San Francisco , CA , USA , and.
authors.forename: Sanae
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: a Department of Obstetrics , Gynecology, and Reproductive Sciences, Division of Maternal-Fetal Medicine, University of California , San Francisco , CA , USA , and.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Gonzalez
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001724:Birth Weight; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D006973:Hypertension; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011225:Pre-Eclampsia; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin / Q000502:physiology*; D012189:Retrospective Studies; D014429:Twins, Dizygotic / Q000706:statistics & numerical data
keywords: Discordance; growth restriction; multiple gestation; preeclampsia; small for gestational age