What are the implications of a low-lying placenta, also known as placenta previa?

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Last updated: April 12, 2025View editorial policy

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From the Guidelines

If you have a low-lying placenta, you should avoid sexual intercourse, strenuous activity, and vaginal examinations until cleared by your healthcare provider. This condition often resolves on its own as the pregnancy progresses and the uterus grows, with the placenta appearing to move away from the cervix. Your doctor will monitor this with ultrasounds, typically scheduling a follow-up scan around 32 weeks 1. If the placenta remains low-lying or develops into placenta previa (completely covering the cervix), you may need to deliver via cesarean section. Watch for warning signs like vaginal bleeding, which can range from light spotting to heavy hemorrhage, and contact your healthcare provider immediately if bleeding occurs. Low-lying placenta poses risks because the placenta contains many blood vessels, and its proximity to the cervix can lead to bleeding, especially during cervical dilation or labor.

Some key points to consider:

  • The management of low-lying placenta involves careful monitoring and avoidance of activities that may exacerbate the condition 1.
  • Ultrasound evaluation is crucial in diagnosing and monitoring low-lying placenta, but clinical risk factors are also important predictors of the condition 1.
  • Delivery at a level III or IV center with considerable experience is recommended for women with suspected placenta accreta spectrum, which includes low-lying placenta 1.
  • The timing of delivery is planned carefully on a case-by-case basis, typically between 34 to 38 weeks of gestation, to achieve optimal fetal maturity and avoid the chance of spontaneous labor 1.

It is essential to follow the specific management plan created by your healthcare team based on the exact position of your placenta and your pregnancy's progression. Regular follow-up appointments and ultrasounds will help monitor the condition and ensure the best possible outcome for both you and your baby.

From the Research

Definition and Diagnosis of Low-Lying Placenta

  • A low-lying placenta is defined as a placenta that is positioned close to the internal os of the cervix, with a distance of 20 mm or less between the placental edge and the internal os 2.
  • The diagnosis of low-lying placenta is typically made using transvaginal ultrasound, which can accurately measure the distance between the placenta and the internal os 3, 4.

Risks and Complications Associated with Low-Lying Placenta

  • Women with low-lying placenta are at increased risk of bleeding complications, including antepartum hemorrhage and postpartum hemorrhage 2, 3, 4.
  • The risk of bleeding complications is higher in women with a shorter distance between the placenta and the internal os 2.
  • Women with low-lying placenta are also at increased risk of emergency cesarean section due to hemorrhage 2.

Management and Treatment of Low-Lying Placenta

  • The management of low-lying placenta typically involves close monitoring and surveillance, with the goal of minimizing the risk of bleeding complications 5, 3.
  • Women with low-lying placenta may be offered a trial of labor, but the decision to do so should be made on a case-by-case basis, taking into account the individual woman's risk factors and medical history 2, 3.
  • Antenatal corticosteroids may be administered to women with low-lying placenta who are at risk of preterm birth, in order to reduce the risk of neonatal morbidity and mortality 5, 6.

Prognosis and Outcomes for Women with Low-Lying Placenta

  • Women with low-lying placenta who experience resolution of the condition by term are still at increased risk of postpartum hemorrhage compared to women with normal placentation throughout pregnancy 4.
  • The prognosis for women with low-lying placenta is generally good, but the condition requires close monitoring and management in order to minimize the risk of complications 2, 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Vaginal delivery in women with a low-lying placenta: a systematic review and meta-analysis.

BJOG : an international journal of obstetrics and gynaecology, 2019

Research

Bleeding complications in pregnancies with low-lying placenta.

The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, 2016

Research

Patients with resolution of low-lying placenta and placenta previa remain at increased risk of postpartum hemorrhage.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2022

Research

Optimal timing of antenatal corticosteroids in women with bleeding placenta previa or low-lying placenta.

The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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