title: Erythrocytosis in offspring of mothers with Type 1 diabetes--are factors other than insulin critical determinants?
abstract: OBJECTIVE
  Maternal diabetes is associated with polycythaemia and thrombocytopaenia in the offspring; however, the relationship with fetal hormones is unknown. We assessed the association of maternal glycaemic control, birthweight and fetal hormones with haematological indices in pregnancies complicated by maternal diabetes.
  
  
  METHODS
  Prospective study using cord blood samples from 89 offspring of mothers with Type 1 diabetes (OT1DM) and 34 control offspring. Full blood count, insulin, leptin, adiponectin, cortisol, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3, intercellular adhesion molecule 1 and C-reactive protein were measured in the umbilical vein at birth.
  
  
  RESULTS
  Haematocrit was higher in OT1DM (OT1DM 0.55 +/- 0.17%, control offspring 0.51 +/- 0.06%; P = 0.02). The difference in platelets count was not statistically significant [OT1DM 214 x 10(9)/l (173-259); control offspring 253 x 10(9)/l (180-310), P = 0.06]. Maternal glycated haemoglobin (HbA(1c)) showed a moderate positive correlation with fetal haematocrit (r = 0.30, P = 0.02). Cord platelet counts were negatively associated with birthweight in OT1DM (r = -0.27, P = 0.01). In multivariate models, cord insulin was not associated with haematocrit, but cord leptin was negatively associated with platelets in control offspring (P < 0.001) and OT1DM (P = 0.046), with additional contributions from male sex (P = 0.08) in OT1DM, and IGF-1 (P = 0.04) and insulin (P = 0.04) in control offspring.
  
  
  CONCLUSIONS
  Fetal haematocrit is increased in response to diabetes in pregnancy and is related to maternal glycaemic control. Fetal hyperinsulinism, hyperleptinaemia or macrosomia, although readily demonstrable in this cohort, do not emerge as determinants of raised fetal haematocrit in OT1DM. Both increased birthweight and fetal leptin are negatively associated with platelet count.
authors.affiliation: Faculty of Medicine, University of Glasgow, Glasgow, G31 ER, UK. s.nelson@clinmed.gla.ac.uk
authors.forename: S M
authors.initials: SM
authors.lastname: Nelson
authors.forename: D J
authors.initials: DJ
authors.lastname: Freeman
authors.forename: N
authors.initials: N
authors.lastname: Sattar
authors.forename: R S
authors.initials: RS
authors.lastname: Lindsay
mesh_terms: D015415:Biomarkers / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005260:Female; D005312:Fetal Blood; D005320:Fetal Macrosomia / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D008297:Male; D011086:Polycythemia / Q000097:blood* / Q000150:complications; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood*; D011254:Pregnancy in Diabetics / Q000097:blood*; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D020738:Leptin; D007334:Insulin-Like Growth Factor I