title: Obstetric antecedents for preterm delivery.
abstract: OBJECTIVE
  To investigate the obstetric antecedents for preterm delivery (PTD) in an Irish urban obstetric population, and to evaluate the incidence and outcome of such deliveries.
  
  
  METHODS
  A retrospective observational study of all preterm deliveries at the Rotunda Hospital, Dublin during the six-year period 1997-2002. The findings for early preterm deliveries (EPTD) (24+0-31+6 weeks' gestation), and late preterm deliveries (LPTD) (32+0-36+6 weeks' gestation) were analyzed separately.
  
  
  RESULTS
  There were 38,795 deliveries after 24 weeks' gestation or >500 g birth weight, of which 2839 (7.3%) were preterm. Of all preterm deliveries, 626 (22.1%) were EPTD and 2213 (77.9%) were LPTD, resulting in an EPTD rate of 1.6% and an LPTD rate of 5.7%. Spontaneous unexplained preterm delivery accounted for 1221 (43.0%) of preterm deliveries (PTD), and of these 213 (34%) cases were EPTD and 1008 (45.5%) LPTD. The other most frequently observed obstetric causative factors, in order of importance, were multiple gestation (676; 23.8% of PTD), hypertensive disorders of pregnancy (243; 8.6%), antepartum hemorrhage (194; 6.8%), stillbirth (105; 3.7%), intrauterine growth restriction (53; 1.9%) and preterm prelabor rupture of membranes+/-chorioamnionitis (32; 1.1%). There were 75 early neonatal deaths among infants born prematurely, plus 105 stillbirths, resulting in a perinatal mortality rate of 63 per 1000 for PTD (n=180), which on subsequent analysis was 158 per 1000 for EPTD (n=99) and 37 per 1000 for LPTD (n=81).
  
  
  CONCLUSIONS
  These data outline the obstetric factors linked to preterm delivery within a recent Irish urban obstetric population. Spontaneous idiopathic preterm labor was the principle causative factor in 43% of all preterm deliveries, and represents the proportion of women for whom future therapeutic intervention may be of benefit.
authors.affiliation: Rotunda Hospital, Parnell Square, Dublin 1, Ireland. mlslattery@hotmail.com
authors.forename: Michael M
authors.initials: MM
authors.lastname: Slattery
authors.forename: Michael
authors.initials: M
authors.lastname: Geary
authors.forename: John J
authors.initials: JJ
authors.lastname: Morrison
mesh_terms: D000367:Age Factors; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology; D015994:Incidence; D007231:Infant, Newborn; D007494:Ireland / Q000453:epidemiology; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D010298:Parity; D011247:Pregnancy; D011272:Pregnancy, Multiple; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D050497:Stillbirth / Q000453:epidemiology; D014505:Urban Population