title: Incidence and recurrence rate of placental abruption: a longitudinal linked national cohort study in the Netherlands.
abstract: OBJECTIVE
  Women who have experienced a placental abruption have a risk of recurrence, but exact information to quantify this risk is currently not available. We studied the incidence and recurrence rate of placental abruption in a subsequent pregnancy and the influence of hypertensive disorders.
  
  
  METHODS
  We conducted a retrospective national cohort study of all singleton pregnancies that ended from 1999-2007 in the Netherlands. A longitudinal linked national cohort of these women with information on a subsequent singleton delivery was used. We calculated and compared incidence and recurrence rates of placental abruption for women in total, stratified by gestational age of first placental abruption and by the presence of a hypertensive disorder in their first pregnancy.
  
  
  RESULTS
  We studied 1,570,635 women of which 3496 (0.22%) experienced a placental abruption. Information was available on a subsequent singleton delivery for 264,424 deliveries. Of these, 521 women (0.20%) had a placental abruption in the first pregnancy vs 214 women (0.08%) in the second pregnancy. The risk of placental abruption in a subsequent pregnancy was significantly higher in women with a previous placental abruption compared with women without (5.8% vs 0.06%; adjusted odds ratio [aOR], 93; 95% confidence interval [CI], 62-139). Women with a placental abruption that occurred at term in their first pregnancy were more at risk for recurrence (aOR, 188; 95% CI, 116-306) than women with a preterm (aOR, 52; 95% CI, 25-111) or early preterm (<32 weeks of gestation) placental abruption in their first pregnancy (aOR, 39; 95% CI, 13-116). Placental abruption was more frequent among women with a hypertensive disorder compared with normotensive women (0.44% vs 0.16%; odds ratio, 2.7; 95% CI, 2.3-3.3). Women with a hypertensive disorder were less at risk for recurrence than were normotensive women (aOR, 0.68; 95% CI, 0.27-1.6). No interaction between a hypertensive disorder in the first pregnancy and the recurrence risk was found.
  
  
  CONCLUSIONS
  Women with a placental abruption in their first pregnancy have a greatly increased risk of placental abruption in a subsequent pregnancy. Hypertensive disorders increase the risk of placental abruption but do not increase the recurrence rate in a subsequent pregnancy. We suggest elective induction from 37 weeks of gestation for women with a history of placental abruption at term in a previous pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, the Netherlands. Electronic address: l.ruiter@amc.nl.
authors.forename: Laura
authors.initials: L
authors.lastname: Ruiter
authors.affiliation: Department of Medical Informatics, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Anita C J
authors.initials: AC
authors.lastname: Ravelli
authors.affiliation: Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Irene M
authors.initials: IM
authors.lastname: de Graaf
authors.affiliation: Robinson Institute, School of Pediatrics and Reproductive Health, University of Adelaide, SA, Australia.
authors.forename: Ben Willem J
authors.initials: BW
authors.lastname: Mol
authors.affiliation: Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Eva
authors.initials: E
authors.lastname: Pajkrt
mesh_terms: D000037:Abruptio Placentae / Q000453:epidemiology*; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology*; D015994:Incidence; D008137:Longitudinal Studies; D009426:Netherlands / Q000453:epidemiology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012008:Recurrence; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D012923:Social Class; D055815:Young Adult
keywords: hypertension; incidence; placental abruption; recurrence