Editor's Note: One of the more frequent questions we hear is “Will I have preeclampsia during future pregnancies?" We asked Dr. Ira Bernstein, a member of the Preeclampsia Foundation Medical Advisory Board, to provide some insight in this "Ask An Expert" article.

Most women with a history of preeclampsia have healthy pregnancies in the future.  However, there is an increased risk of developing preeclampsia or gestational hypertension in subsequent pregnancies when compared to first pregnancies.  Studies have reported recurrence rates for preeclampsia varying from less than 10% to more than 60%, depending on the population studied and the gestational age at onset in the first pregnancy. 

A recent analysis on the recurrence of hypertensive disorders of pregnancy showed an overall recurrence rate of 20.7%(1).  When looking only at the recurrence of preeclampsia, it was 13.8%.  When preeclampsia was diagnosed early in the pregnancy or was more severe there was an increased risk of recurrence.  Fortunately, when preeclampsia did recur it tended to be milder and later in onset than in the first affected pregnancy. 

Specific high-risk factors, like high blood pressure, diabetes, twin pregnancy, kidney or autoimmune disease significantly increase the risk of preeclampsia recurrence.  Other factors that modestly increase the risk of preeclampsia are obesity, maternal age greater than 35, family history of preeclampsia, low socioeconomic status and certain characteristics like African American race.  Fortunately low-dose aspirin taken during pregnancy has been shown to decrease the risk of preeclampsia by about 24% in women who are at high risk (2).  

Interestingly, women who conceive another pregnancy within a few years following a pregnancy complicated by preeclampsia have a lower risk of having preeclampsia again than if they wait longer to conceive.  Also, in the absence of other high-risk factors, the risk for preeclampsia is highest in a woman’s first pregnancy and declines thereafter.  Based on these observations, it seems that having a pregnancy, even if it is complicated by preeclampsia, provides some temporary protection from having preeclampsia in the next pregnancy. 

One important factor may be the effect of pregnancy itself on a woman’s cardiovascular system.   Women studied an average of 14 months postpartum have been shown to have lower blood pressure and more elastic blood vessels when compared to themselves prior to pregnancy. This may represent the modification of important risk factors (3).  This effect of pregnancy seems to fade over time, with blood pressure and vessel stiffness returning toward baseline over several years after pregnancy. 

An alternative explanation for the increase recurrence of preeclampsia with a longer inter-pregnancy interval is the potential role for new paternity (4).  Primipaternity, or a first father effect, also appears to be a risk factor for preeclampsia both in women with a prior pregnancy and women with longer intervals between pregnancies, who have a greater likelihood of having a new partner.  

Overall, women who have had a pregnancy complicated by preeclampsia can be optimistic that it is relatively unlikely to happen again.  The best protection is to improve modifiable risk factors by maintaining a healthy weight and engaging in regular physical activity, taking low-dose aspirin in future pregnancies and planning future pregnancies within a few years of the first.

Erin Morris, MD Assistant Professor
Ira M. Bernstein MD Professor and John Van Sicklen Maeck Chair
Department of Obstetrics Gynecology and Reproductive Sciences  Robert Larner, MD College of Medicine at the University of Vermont

References:

1. van Oostwaard MF, Langenveld J, Schuit E, et al. Recurrence of hypertensive disorders of pregnancy: an individual patient data metaanalysis. American journal of obstetrics and gynecology. May 2015;212(5):624.e621-617.

2. Henderson JT, Whitlock EP, O'Conner E, Senger CA, Thompson JH, Rowland MG. U.S. Preventive Services Task Force Evidence Syntheses, formerly Systematic Evidence Reviews. Low-Dose Aspirin for the Prevention of Morbidity and Mortality From Preeclampsia: A Systematic Evidence Review for the U.S. Preventive Services Task Force. Rockville (MD): Agency for Healthcare Research and Quality (US); 2014.

3. Morris EA, Hale SA, Badger GJ, Magness RR, Bernstein IM. Pregnancy induces persistent changes in vascular compliance in primiparous women. American journal of obstetrics and gynecology. May 2015;212(5):633.e631-636. 4. Robillard PY1, Dekker GA, Hulsey TC.l Primipaternities in families: is the incidence of pregnancy-induced hypertensive disorders in multigravidas an anthropological marker of reproduction? Aust N Z J Obstet Gynaecol. 1998 Aug;38(3):284-7.