title: Early-onset preeclampsia appears to discourage subsequent pregnancy but the risks may be overestimated.
abstract: BACKGROUND
  Early-onset preeclampsia is associated with adverse maternal and perinatal outcomes. For women who consider another pregnancy after one complicated by early-onset preeclampsia, the likelihood of recurrence and the subsequent pregnancy outcome for themselves and their babies are pertinent considerations.
  
  
  OBJECTIVE
  The purpose of this study was to determine the subsequent pregnancy rate after a nulliparous pregnancy that was complicated by early-onset preeclampsia and among those who have a subsequent pregnancy, the risk of recurrence by gestational week, and adverse pregnancy outcomes.
  
  
  METHODS
  This was a population-based record linkage cohort study. The study population included nulliparous women with a singleton pregnancy and early-onset preeclampsia (<34 weeks gestation) who gave birth in New South Wales Australia from 2001-2010 (the index birth), with follow-up data for a subsequent birth through 2012. Early-onset in the index birth was further categorized as <28 vs 28-33 weeks gestation. Subsequent pregnancy outcomes that were assessed included the pregnancy rate, preeclampsia recurrence, and maternal and perinatal morbidity and mortality rates. The risk of preeclampsia necessitating delivery at each gestational week for women who were at risk was plotted, and the net gain or loss of gestational age when comparing the index with the subsequent pregnancy was calculated.
  
  
  RESULTS
  Among 361,031 nulliparous women with singleton pregnancies, 1473 (0.4%) had early-onset preeclampsia. Women with early-onset preeclampsia in their first pregnancy had a lower subsequent pregnancy rate (59.7%) than women without preeclampsia (67.7%). Of the 758 women with a subsequent singleton birth, 256 (33.8%) experienced preeclampsia in the next pregnancy; 57 women (7.5%) with recurrent early-onset preeclampsia were included. Cumulative rates of preeclampsia in the subsequent pregnancy were higher at every gestation from 23 weeks gestation when the index birth was <28 weeks compared with 28-33 weeks gestation. The cumulative rate and gestation-specific risk of recurrent preeclampsia rose most steeply at 32-38 weeks gestation. Most women (94.6%) progressed to a later gestational age in their subsequent pregnancy. The median overall increase in gestational age at delivery was 6 weeks (interquartile range, 4-8); among women with recurrent preeclampsia, the median increase was 5 weeks (interquartile range, 2-7). Women with index birth <28 weeks gestation compared with 28-33 weeks gestation were more likely to deliver preterm (38.8% vs 28.7%; relative risk, 1.35; 95% confidence interval, 1.04-1.75) and have a perinatal death (4.3% vs 1.2%; relative risk, 3.46; 95% confidence interval, 1.15-10.39) at the subsequent birth, but live born infants had similar rates of severe morbidity (17.1% vs 15.0%; relative risk, 1.14; 95% confidence interval, 0.73-1.79).
  
  
  CONCLUSIONS
  Women with early-onset preeclampsia in a first pregnancy appear less likely than women without preeclampsia to have a subsequent pregnancy. Maternal and perinatal outcomes in the subsequent pregnancy are generally better than in the first; most women will not have recurrent preeclampsia, and those who do usually will give birth at a greater gestational age compared with their index birth.
authors.affiliation: Clinical and Population Perinatal Health, Kolling Institute, Northern Sydney Local Heath District, St. Leonards, and Sydney Medical School Northern, University of Sydney, Sydney, New South Wales, Australia. Electronic address: sean.seeho@sydney.edu.au.
authors.forename: Sean K
authors.initials: SK
authors.lastname: Seeho
authors.affiliation: Clinical and Population Perinatal Health, Kolling Institute, Northern Sydney Local Heath District, St. Leonards, and Sydney Medical School Northern, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Algert
authors.affiliation: Clinical and Population Perinatal Health, Kolling Institute, Northern Sydney Local Heath District, St. Leonards, and Sydney Medical School Northern, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Roberts
authors.affiliation: Clinical and Population Perinatal Health, Kolling Institute, Northern Sydney Local Heath District, St. Leonards, and Sydney Medical School Northern, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Jane B
authors.initials: JB
authors.lastname: Ford
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D020073:Gravidity; D006801:Humans; D016247:Information Storage and Retrieval; D009517:New South Wales / Q000453:epidemiology; D010298:Parity; D066087:Perinatal Death; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D047928:Premature Birth / Q000453:epidemiology*; D012008:Recurrence; D055815:Young Adult
keywords: early-onset; preeclampsia; pregnancy outcome; recurrence; risk