title: Mid-pregnancy maternal leptin levels, birthweight for gestational age and preterm delivery.
abstract: OBJECTIVE
  Maternal blood leptin levels are positively associated with adiposity. Recent studies suggest that leptin is also abundantly produced by the placenta and may function as a regulator of foetal growth. Our goal was to examine mid-pregnancy levels of leptin in maternal blood in relation to birthweight for gestational age (BW/GA) and timing of delivery after accounting for maternal prepregnancy body mass index (prepreg-BMI) and pregnancy complications.
  
  
  METHODS
  Data were from 1304 subcohort mother/infant pairs who participated in the Pregnancy Outcomes and Community Health (POUCH) Study (1998-2004).
  
  
  METHODS
  Leptin levels, measured at 16-27 weeks' gestation, were log-transformed. Geometric mean (GMean) leptin levels were estimated by weighted linear regression with gestational age at blood draw as a covariate. GMean was re-transformed to the original scale for reporting.
  
  
  RESULTS
  Using the GMeans leptin in mothers of term appropriate-for-gestational age (AGA) neonates as the referent (25·2 μg/l), we observed lower levels in mothers of preterm-AGA (21·9 μg/l), term small-for-gestational age (SGA) (20·3 μg/l) and preterm-SGA neonates (21·7 μg/l). Results were largely unchanged after adjustment for prepreg-BMI. Leptin levels were higher in mothers who delivered large-for-gestational age (LGA) neonates, both preterm (33·6 μg/l) and term (29·1 μg/l), but the GMeans were markedly attenuated after adjustment for prepreg-BMI.
  
  
  CONCLUSIONS
  The association between BW/GA and maternal leptin levels after adjustment for prepreg-BMI may represent: (i) a residual effect of maternal adiposity that is not fully captured by BMI; and/or (ii) variation in placental leptin levels entering the maternal circulation. In conclusion, mid-pregnancy maternal blood leptin levels may be an early indicator of foetal growth status.
authors.affiliation: Michigan Public Health Institute, Okemos, MI, USA.
authors.forename: Monal R
authors.initials: MR
authors.lastname: Shroff
authors.forename: Claudia
authors.initials: C
authors.lastname: Holzman
authors.forename: Yan
authors.initials: Y
authors.lastname: Tian
authors.forename: Rhobert W
authors.initials: RW
authors.lastname: Evans
authors.forename: Alla
authors.initials: A
authors.lastname: Sikorskii
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology; D015992:Body Mass Index; D036861:Delivery, Obstetric; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D020738:Leptin / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology; D011262:Pregnancy Trimester, Second / Q000097:blood*; D047928:Premature Birth / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D055815:Young Adult
chemical_list: D020738:Leptin