title: The impact of maternal height on intrapartum operative delivery: a reappraisal.
abstract: OBJECTIVE
  To clarify the relationship between maternal height and intrapartum operative delivery in women with singleton pregnancies.
  
  
  METHODS
  A retrospective cohort study was performed on Asian, mostly southern Chinese, women managed by our department in a 48-month period. They were categorized into four quartile groups according to their height ranking, with the 25th, 50th and 75th percentile values of height generated from the entire obstetric population. The labor and pregnancy outcomes of different quartile groups were compared.
  
  
  RESULTS
  A total of 13 606 pregnancies were recruited in the study cohort. The 25th, 50th and 75th percentile values of maternal height were 153 cm, 156 cm, and 160 cm, respectively, and the number of cases from the lowest to the highest quartile groups was 4153, 2698, 3445, and 3310, respectively. Significant differences were found in maternal weight, body mass index, incidences of multiparity and smokers, and birthweight and Apgar score at the first minute among the four quartiles. There was a significantly increasing incidence of cesarean delivery for mechanical reasons in spite of higher incidences of small-for-gestational age (SGA) and low birthweight (LBW) infants in decreasing quartiles. Regression analysis confirmed that the lower three quartile groups were associated with significantly increased cesarean delivery rates compared with the highest quartile group.
  
  
  CONCLUSIONS
  Maternal height is inversely correlated with the risk of cesarean delivery for labor arrest The effect of height acts as a continuum rather than in a dichotomous manner. The use of height percentile ranking may allow comparison between different populations on the effect on labor outcome.
authors.affiliation: Department of Obstetrics & Gynaecology, Queen Mary Hospital, Hong Kong, China. bcpchan@hkucc.hku.hk
authors.forename: Ben C P
authors.initials: BC
authors.lastname: Chan
authors.forename: Terence T H
authors.initials: TT
authors.lastname: Lao