title: Caesarean section at term: the relationship between neonatal respiratory morbidity and microviscosity in amniotic fluid.
abstract: OBJECTIVE
  The incidence of neonatal respiratory morbidity following an elective caesarean section is 2-3 times higher than after a vaginal delivery. The microviscosity of surfactant phospholipids, as measured with fluorescence polarisation, is linked with the functional characteristics of fetal surfactant and thus fetal lung maturity, but so far this point has received little attention in newborns at term. The aim of the study is to evaluate the correlation between neonatal respiratory morbidity and amniotic microviscosity (Fluorescence Polarisation Index) in women undergoing caesarean section after 37 weeks' gestation.
  
  
  METHODS
  The files of 136 women who had undergone amniotic microviscosity studies during elective caesarean deliveries at term were anonymised. Amniotic fluid immaturity (AFI) was defined as a Fluorescence Polarisation Index higher than 0.335.
  
  
  RESULTS
  Respiratory morbidity was observed in 10 babies (7.3%) and was independently associated with AFI (OR: 6.11 [95% CI, 1.20-31.1] with p=0.029) and maternal body mass index (OR: 1.12 [95% CI, 1.02-1.22] with p=0.019). Gestational age at the time of caesarean delivery was inversely associated with AFI (odds ratio, 0.46 [95% confidence interval, 0.29-0.71], p<0.001), especially before 39 weeks, and female gender was associated with an increased risk (odds ratio, 3.29 [95% confidence interval, 1.48-7.31], p=0.004).
  
  
  CONCLUSIONS
  AFI assessed by amniotic microviscosity was significantly associated with respiratory morbidity and independently correlated with shorter gestational age especially before 39 weeks. This finding provides a physiological rationale for recommending delaying elective caesarean section delivery until 39 weeks of gestation to decrease the risk for respiratory morbidity.
authors.affiliation: Department of Obstetrics, Rennes University Hospital, Rennes, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Lavoué
authors.forename: Laure
authors.initials: L
authors.lastname: Voguet
authors.forename: Bruno
authors.initials: B
authors.lastname: Laviolle
authors.forename: Caroline
authors.initials: C
authors.lastname: Piau
authors.forename: Marie Pascale
authors.initials: MP
authors.lastname: Beaumont
authors.forename: Laure-Anne
authors.initials: LA
authors.lastname: Haumont
authors.forename: Hélène
authors.initials: H
authors.lastname: Isly
authors.forename: Linda
authors.initials: L
authors.lastname: Lassel
authors.forename: Estelle
authors.initials: E
authors.lastname: Bauville
authors.forename: Karine
authors.initials: K
authors.lastname: Morcel
authors.forename: Patrick
authors.initials: P
authors.lastname: Pladys
authors.forename: Patrice
authors.initials: P
authors.lastname: Poulain
authors.forename: Pierre
authors.initials: P
authors.lastname: Bétrémieux
authors.forename: Claude
authors.initials: C
authors.lastname: Bendavid
mesh_terms: D000293:Adolescent; D000328:Adult; D000653:Amniotic Fluid / Q000737:chemistry*; D002585:Cesarean Section / Q000009:adverse effects*; D005260:Female; D005454:Fluorescence Polarization; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000737:chemistry*; D011247:Pregnancy; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000209:etiology*; D012189:Retrospective Studies; D014783:Viscosity; D055815:Young Adult
chemical_list: D010743:Phospholipids
keywords: Caesarean section; Fluorescence polarisation; Microviscosity; Respiratory morbidity; Surfactant