What is preeclampsia?

The American College of Obstetricians and Gynecologists (ACOG) and the International Society for the Study of Hypertension in Pregnancy (ISSHP) define preeclampsia as hypertension developing most often after 20 weeks of gestation and the coexistence of one or more of the following new onset conditions: protein in the urine, dysfunction of maternal organs (including the kidneys, liver, neurological system, pulmonary edema or hematological complications), or uteroplacental dysfunction, which can lead to restricted fetal growth caused by a restriction of oxygen and nutrients.^1,2

Preeclampsia can advance quickly and lead to serious complications, including seizures (eclampsia); stroke; renal impairment; hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome); and the risk of death for both the mother and the fetus.¹ A 2011 prospective study of women admitted to the hospital (n=2,023) found that 12.9% of women with pre-eclampsia had adverse maternal outcomes defined as maternal mortality or one or more serious central nervous system, cardiorespiratory, hepatic, renal, or hematological morbidity.³ 

A 2013 population-based study compared birth outcomes between 1,752 women with preeclampsia diagnosed <34 weeks and 454,916 women without preeclampsia.⁴ Outcomes were significantly worse among those with preeclampsia, with 3.3% vs 0.36% fatal death, 68.6% vs 4.9% admission to the neonatal intensive care unit (NICU), 20.9% vs 1.26% severe neonatal morbidity (seizures, sepsis, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage grades 3 and 4, periventricular leukomalacia, and retinopathy of prematurity), 2.9% vs 0.24% neonatal death, and 6.2% vs 0.60% perinatal death. 

In a 2015 prospective cohort study (n=323) of women with preeclampsia, 18.3% had adverse maternal outcomes (including hepatic dysfunction, eclampsia, coma, cardiovascular events, cortical blindness or retinal detachment, acute renal insufficiency or failure, pulmonary complications, placental abruption, and mortality), 42.8% had adverse fetal outcomes (including bronchopulmonary dysplasia, necrotizing enterocolitis, grade 3 or 4 intraventricular hemorrhage, cystic periventricular leukomalacia, stages 3-5 retinopathy of prematurity, and perinatal or infant mortality), and 13.35% had combined adverse maternal and perinatal outcomes.⁵

Preeclampsia is a leading cause of maternal and perinatal mortality worldwide and complicates 2% to 8% of pregnancies.⁶ A 2014 World Health Organization meta-analysis estimated that hypertensive disorders are the cause of death in about 14% of maternal deaths worldwide.⁷ An analysis of pregnancy-related ICU admissions in Maryland from 1999-2008 (n=2,927) found that 29.9% of hospital admissions and 25.8% of mortalities were due to pregnancy-related hypertensive disease.⁸ A cross-sectional study found that from 1998-2006 (n=36,537,061), the incidence of preeclampsia was 3.34%.⁹ According to the Centers for Disease Control and Prevention (CDC), between 2017 and 2019, the prevalence of Hypertensive Disorders in Pregnancy among delivery hospitalizations increased from 13.3% to 15.9%. ¹⁰ In the United States, non-Hispanic black women are disproportionally affected by preeclampsia. A 2021 study of 6,096 women found that the prevalence of preeclampsia was 11.0% among Black Americans compared to 8.8% of Hispanic women and 7.1% of white women.¹¹

Signs and symptoms can sometimes accompany preeclampsia, but it can also be asymptomatic. Signs and symptoms of pre-eclampsia include persistent occipital or frontal headaches, blurred vision and other visual disturbances, hyperreflexia, severe nausea or vomiting, right upper quadrant/epigastric pain, and chest pain/dyspnea.^1,3 A 2015 prospective cohort study (n=323) found that symptoms only occurred in 52.3% of those diagnosed with pre-eclampsia, with 19.2% experiencing headache, 12.4% chest pain or dyspnea, 11.8% right upper quadrant or epigastric pain, and 9.0% visual disturbances.⁵ 

The United States Preventive Services Task Force (USPSTF) recommends screening pregnant women for preeclampsia with blood pressure measurements at each neonatal visit.¹² Without regular blood pressure monitoring, preeclampsia may go unnoticed and be detected only when the condition has become severe.

References

1. Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. Obstet Gynecol. Jun 2020;135(6):e237-e260. doi:10.1097/aog.0000000000003891
2. Tranquilli AL, Dekker G, Magee L, et al. The classification, diagnosis, and management of the hypertensive disorders of pregnancy: A revised statement from the ISSHP. Pregnancy Hypertens. Apr 2014;4(2):97-104. doi:10.1016/j.preghy.2014.02.001
3. von Dadelszen P, Payne B, Li J, et al. Prediction of adverse maternal outcomes in pre-eclampsia: development and validation of the fullPIERS model. Lancet. Jan 15 2011;377(9761):219-27. doi:10.1016/S0140-6736(10)61351-7
4. Lisonkova S, Joseph KS. Incidence of preeclampsia: risk factors and outcomes associated with early- versus late-onset disease. Am J Obstet Gynecol. Dec 2013;209(6):544.e1-544.e12. doi:10.1016/j.ajog.2013.08.019
5. Agrawal S, Maitra N. Prediction of Adverse Maternal Outcomes in Preeclampsia Using a Risk Prediction Model. J Obstet Gynaecol India. Oct 2016;66(Suppl 1):104-11. doi:10.1007/s13224-015-0779-5
6. Duley L. The global impact of pre-eclampsia and eclampsia. Semin Perinatol. Jun 2009;33(3):130-7. doi:10.1053/j.semperi.2009.02.010
7. Say L, Chou D, Gemmill A, et al. Global causes of maternal death: a WHO systematic analysis. Lancet Glob Health. Jun 2014;2(6):e323-33. doi:10.1016/S2214-109X(14)70227-X
8. Wanderer JP, Leffert LR, Mhyre JM, Kuklina EV, Callaghan WM, Bateman BT. Epidemiology of obstetric-related ICU admissions in Maryland: 1999-2008*. Crit Care Med. Aug 2013;41(8):1844-52. doi:10.1097/CCM.0b013e31828a3e24
9. Kuklina EV, Ayala C, Callaghan WM. Hypertensive disorders and severe obstetric morbidity in the United States. Obstet Gynecol. Jun 2009;113(6):1299-1306. doi:10.1097/AOG.0b013e3181a45b25
10. Ford ND, Cox S, Ko JY, et al. Hypertensive Disorders in Pregnancy and Mortality at Delivery Hospitalization - United States, 2017-2019. MMWR Morb Mortal Wkly Rep. Apr 29, 2022;71(17):585-591. doi:10.15585/mmwr.mm7117a1
11. Boakye E, Kwapong YA, Obisesan O, et al. Nativity-Related Disparities in Preeclampsia and Cardiovascular Disease Risk Among a Racially Diverse Cohort of US Women. JAMA Netw Open. Dec 01 2021;4(12):e2139564. doi:10.1001/jamanetworkopen.2021.39564
12. Bibbins-Domingo K, Grossman DC, Curry SJ, et al. Screening for Preeclampsia: US Preventive Services Task Force Recommendation Statement. Jama. Apr 25 2017;317(16):1661-1667. doi:10.1001/jama.2017.3439