title: Amniotic fluid and maternal blood characteristics in severe mid-trimester twin-twin transfusion syndrome.
abstract: OBJECTIVE
  To investigate the concentrations of metabolic variables in the amniotic fluid of the recipient twin and maternal blood and to correlate them with clinical features, which are characteristic for the course of pregnancies with twin-twin transfusion syndrome (TTS).
  
  
  METHODS
  In 109 pregnancies with severe mid-trimester TTS, we measured the concentrations of interleukin-6 (IL-6), alpha-fetoprotein (AFP), sodium, potassium, total protein, beta2-microglobulin and osmolality in the amniotic fluid of the recipient twin prior to laser coagulation of the vascular anastomoses and compared them to a control group of 92 singleton pregnancies. We measured the pulsatility index (PI) of ductus venosus flow velocity waveforms in the recipient twin and performed a retrospective chart analysis for complete maternal blood count before and after the procedure.
  
  
  RESULTS
  All variables, except osmolality, IL-6 and AFP were significantly lower in the TTS group. There was a significant positive correlation between PI in the ductus venosus and the amniotic fluid AFP concentrations (r = 0.355; p < 0.001). There was a significant fall in complete maternal blood count after laser therapy (p < 0.001) and a significant correlation between the amount of amniotic fluid drained and the fall of maternal Hb (r = -0.261; p = 0.03) and hematocrit (r = -0.212; p = 0.01).
  
  
  CONCLUSIONS
  Pathophysiologic changes in TTS do not only occur at the inter-twin level of placental vascular anastomoses but also at the materno-fetal level of fluid exchanges. AFP is correlated to the severity of congestive heart failure of the recipient twin.
authors.affiliation: Department of Prenatal Diagnosis and Therapy, Barmbek Hospital, Hamburg, Germany.
authors.forename: Agnes
authors.initials: A
authors.lastname: Huber
authors.forename: Werner
authors.initials: W
authors.lastname: Diehl
authors.forename: Liza
authors.initials: L
authors.lastname: Zikulnig
authors.forename: Karsten R
authors.initials: KR
authors.lastname: Held
authors.forename: Thomas
authors.initials: T
authors.lastname: Bregenzer
authors.forename: B-Joachim
authors.initials: BJ
authors.lastname: Hackelöer
authors.forename: Kurt
authors.initials: K
authors.lastname: Hecher
mesh_terms: D000653:Amniotic Fluid / Q000378:metabolism*; D005260:Female; D005330:Fetofetal Transfusion / Q000378:metabolism* / Q000601:surgery; D006400:Hematocrit; D006454:Hemoglobins; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D017075:Laser Coagulation; D007958:Leukocyte Count; D009994:Osmolar Concentration; D010976:Platelet Count; D011188:Potassium / Q000378:metabolism; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012964:Sodium / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D015850:Interleukin-6; D000509:alpha-Fetoproteins; D001613:beta 2-Microglobulin; D012964:Sodium; D011188:Potassium