title: The role of antenatal factors on tibial speed of sound values in newborn infants.
abstract: OBJECTIVE
  To evaluate the role of some antenatal factors on bone status of newborn infants.
  
  
  METHODS
  Tibial bone speed of sound (SOS) value was measured by quantitative ultrasound within 5 days after birth in 205 neonates whose gestational ages ranged between 31 and 40 weeks. The cohort was divided into two groups according to intrauterine growth curves, as small- (SGA) and appropriate-for-gestational age (AGA). All cases were also been evaluated by antenatal ultrasonography for oligohydroamniosis.
  
  
  RESULTS
  The mean SOS value was found significantly higher in SGA (n = 43) than AGA infants (n = 162) (p < 0.001). The mean tibial SOS value of infants with a history of oligohydroamniosis (n = 28) was also higher than those without oligohydroamniosis (n = 177) (p < 0.001). But, in SGA infants with a history of oligohydroamniosis (n = 17), the mean tibial SOS value was similar to those SGA infants without oligohydroamniosis (n = 26) (p > 0.05). Infants whose mothers had smoked during pregnancy (n = 18) had significantly higher tibial SOS values compared to those of whose mothers had not (n = 187) (p = 0.006). In addition, mean tibial SOS values were determined higher in male infants (n = 116) compared to female infants (n = 89) (p = 0.036). There was a significant correlation between tibial SOS values and gestational age (r = 0.178, p = 0.011).
  
  
  CONCLUSIONS
  While creating reference curves of SOS values at birth, smallness for gestational age, maternal smoking and gender as well as gestational age should be taken into account.
authors.affiliation: Department of Pediatrics, Division of Neonatology, Dr. Sami Ulus Maternity and Children Training and Research Hospital, Ankara, Turkey.
authors.forename: Mehmet Sah
authors.initials: MS
authors.lastname: Ipek
authors.forename: Aysegul
authors.initials: A
authors.lastname: Zenciroglu
authors.forename: Mustafa
authors.initials: M
authors.lastname: Aydin
authors.forename: Nurullah
authors.initials: N
authors.lastname: Okumus
authors.forename: Sara Surmeli
authors.initials: SS
authors.lastname: Erol
authors.forename: Belma Saygili
authors.initials: BS
authors.lastname: Karagol
authors.forename: Nilay
authors.initials: N
authors.lastname: Hakan
mesh_terms: D015519:Bone Density; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D007234:Infant, Premature / Q000502:physiology; D007236:Infant, Small for Gestational Age / Q000502:physiology; D016014:Linear Models; D008297:Male; D008425:Maternal Behavior; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000000981:diagnostic imaging; D012016:Reference Values; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D013977:Tibia / Q000000981:diagnostic imaging* / Q000502:physiology; D016216:Ultrasonography, Prenatal