How Preeclampsia May Affect Your Pregnancy With Multiples

Pregnant Woman

Frederic Cirou/PhotoAlto/Getty Images

Table of Contents
View All
Table of Contents

Mothers who are pregnant with multiples are at extremely high risk for preeclampsia, also known as toxemia or pregnancy-induced hypertension (PIH). This condition is associated with high blood pressure during pregnancy and it affects up to a third of moms of multiples.

Research is helping doctors understand and diagnose the causes of preeclampsia, which may make it easier to predict and perhaps treat the disorder.


It is estimated that 5% of singleton pregnancies are affected by preeclampsia. However, one in every three mothers of multiples will exhibit symptoms during her pregnancy. The complications from the condition may lead to premature labor or other severe, even fatal, risks to both the mother and baby.

Researchers have identified two proteins produced by the placenta that may be responsible for the development of the condition. The findings point to the FLT1 gene, which is responsible for blood vessel formation in a fetus and present in placental cells of pregnant women. The gene produces certain proteins that, in a high concentration, narrows blood vessels and raises the mother's blood pressure. This impairs the delivery of blood and nutrients to the placenta.

Identifying the gene means that doctors may be better able to rapidly diagnose the condition and develop effective therapies to prevent it.

In the past, diagnosis relied on inconclusive symptoms. By the time the symptoms were exhibited, the blood flow to the placenta may already have been reduced by up to 50%.

As promising as these results are, researchers are cautious and note that it cannot account for many cases of preeclampsia. They also note that more work needs to be done to further understand the connection, improve DNA prediction models, and develop specific medications for treatment.

Symptoms of Preeclampsia

Symptoms of preeclampsia usually develop after the 20th week of pregnancy and are typically detected during a routine checkup. They include:

  • A weekly weight gain of more than two pounds
  • Elevated blood pressure
  • Increased protein in the urine
  • Puffiness in the hands or feet
  • Water retention

More severe symptoms include agitation or confusion, changes in the mother's mental state, nausea or vomiting, headaches, fatigue, abdominal pain, or shortness of breath.


Frequent check-ups with your physician or midwife are imperative for detecting preeclampsia and other pregnancy complications. Your caretaker should carefully monitor your blood pressure, weight gain, and urine output.

Let your doctor know if you have any history of preeclampsia in your family, including your own previous pregnancies. Women who already have hypertension, obesity, diabetes, or kidney disease are also at increased risk.

The standard method for diagnosing preeclampsia for years has been high blood pressure along with high protein levels in urine tests. However, this criteria may miss some cases. It has been found that a woman may have normal protein levels in their urine, but that there are other symptoms doctors can look for. These include decreased blood platelets, kidney or liver problems, and fluid in the lungs.

Testing for these conditions is now included in the guidelines for preeclampsia diagnosis provided to doctors by the American College of Obstetricians and Gynecologists (ACOG).


Ultimately, the only way to "cure" preeclampsia is to deliver the babies. Doctors have to weigh the impact on the mother's health against the condition of the babies, particularly their current development. If the pregnancy is not viable, your doctor may choose to delay delivery.

In some cases, the condition can be controlled by moderating the mother's behavior: increasing your water intake, reducing salt, or instituting a routine of bed rest while lying on your left side to limit pressure on major blood vessels.

Your doctor will also likely require more frequent office visits in order to monitor your blood pressure and urine protein levels or other vitals related to your diagnosis. In more severe cases, hospitalization may be required to ensure complete bed rest.

Medications such as magnesium sulfate or hydralazine may be administered, although the side effects of these drugs can cause further medical issues. In the most severe cases, labor will be induced or a c-section will be performed.

Health Effects on Moms

Once the babies are delivered, the symptoms should subside and the mother's health would no longer be at risk. Women are at risk for developing eclampsia up to six weeks after the delivery of their babies, however. Your doctor will continue to monitor your blood pressure during that postpartum period.

If left unchecked, preeclampsia can damage the mother's kidneys, liver, and brain. Preeclampsia occurs in 1 in 25 pregnancies in the United States each year. Untreated preeclampsia develops into eclampsia, the second leading cause of maternal death in the U.S.

Impact on Babies

Since treatment for preeclampsia requires the delivery of the babies, they are at an increased risk for premature birth. While the impact of prematurity presents a variety of complications, remaining in utero presents its own set of risks.

When blood flow to the placenta is restricted, the fetuses receive reduced oxygen and nutrients. This may produce babies with intrauterine growth retardation (IUGR), low-birth weights, or even stillbirths.

A Word From Verywell

Preeclampsia is a serious complication in pregnancy and one that should not be taken lightly. If you notice any of the symptoms, contact your doctor or midwife immediately and be sure to follow all directions they give you if you're diagnosed with it. Bed rest and diet changes may be difficult, but they are very important for your health as well as that of your babies.

7 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Laine K, Murzakanova G, Sole KB, Pay AD, Heradstveit S, Räisänen S. Prevalence and risk of pre-eclampsia and gestational hypertension in twin pregnancies: a population-based register studyBMJ Open. 2019;9(7):e029908. doi:10.1136/bmjopen-2019-029908

  2. McGinnis R, et al. Variants in the fetal genome near FLT1 are associated with risk of preeclampsiaNatura Genetics. 2017;49:1255-1260. doi:10.1038/ng.3895

  3. Uzan J, Carbonnel M, Piconne O, Asmar R, Ayoubi JM. Pre-eclampsia: pathophysiology, diagnosis, and managementVasc Health Risk Manag. 2011;7:467-474. doi:10.2147/VHRM.S20181

  4. Kallela J, Jääskeläinen T, Kortelainen E, et al. The diagnosis of pre-eclampsia using two revised classifications in the Finnish Pre-eclampsia Consortium (FINNPEC) cohortBMC Pregnancy Childbirth. 2016;16:221. doi:10.1186/s12884-016-1010-0

  5. American College of Obstetricians and Gynecologists. Preeclampsia and high blood pressure during pregnancy.

  6. Townsend R, O'Brien P, Khalil A. Current best practice in the management of hypertensive disorders in pregnancyIntegr Blood Press Control. 2016;9:79-94. doi:10.2147/IBPC.S77344

  7. Centers for Disease Control and Prevention. High blood pressure during pregnancy.

By Pamela Prindle Fierro
 Pamela Prindle Fierro is the author of several parenting books and the mother of twin girls.