What is the clinical significance of subchronic hemorrhages in early pregnancy?

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Last updated: April 4, 2025View editorial policy

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From the Guidelines

Subchronic bleeds in early pregnancy are a significant concern due to their potential to increase the risk of pregnancy complications, including miscarriage and placenta accreta spectrum disorder (PASD). The presence of subchronic bleeds may indicate an underlying issue with placental implantation, which can lead to severe and life-threatening hemorrhage during delivery 1. According to the American College of Radiology, the incidence of PASD has increased over the past decades, and the risk of severe hemorrhage is greatest at the time of delivery when a portion of the placenta does not separate in the usual fashion 1.

Risk Factors and Complications

The risk factors for PASD include prior cesarean delivery, placenta previa, advanced maternal age, and high gravidity or parity 1. The management of delivery in cases of suspected PASD is variable, but the American Congress of Obstetricians and Gynecologists (ACOG) and the International Federation of Obstetrics and Gynecology (FIGO) recommend planned cesarean delivery with or without hysterectomy depending on the suspected severity of PASD around 34 to 38 weeks 1.

Diagnosis and Monitoring

Accurate antenatal diagnosis is crucial to plan for an appropriate delivery strategy at an experienced center to reduce maternal morbidity 1. Imaging, particularly with ultrasound, is the mainstay for making accurate diagnoses and for emergent guidance of management in cases of vaginal bleeding in the second and third trimesters 1. Transabdominal and transvaginal ultrasound are essential tools in the evaluation of cervical-related causes of vaginal bleeding and placenta previa 1.

Recommendations

Close monitoring and timely intervention are essential in cases of subchronic bleeds in early pregnancy to prevent complications and ensure the best possible outcomes for both the mother and the fetus. Patients with suspected PASD should be followed closely by experienced centers, and a contingency plan for emergent delivery should be in place 1. The timing of delivery should be planned carefully on a case-by-case basis to achieve optimal fetal maturity and avoid the chance of spontaneous labor 1.

From the Research

Significance of Subchronic Bleeds in Early Pregnancy

  • Subchronic bleeds, also known as subchorionic hematomas, are a common complication in early pregnancy, affecting up to 40% of pregnant women 2.
  • The presence of subchorionic hematomas has been associated with an increased risk of pregnancy loss, with a higher ratio of hematoma to gestational sac being a significant predictor of pregnancy loss 3.
  • Vaginal bleeding and non-specific pelvic pain are common symptoms of subchorionic hematomas, and their presence can increase the risk of pregnancy complications 3.
  • The use of low-dose aspirin has been shown to increase the risk of subchorionic hematomas, with a four-fold increase in frequency compared to those not taking aspirin 2.
  • Subchorionic hematomas can also be associated with an increased risk of placental abruption and postpartum hemorrhage, particularly in women taking low-dose aspirin 4.

Risk Factors and Associations

  • The ratio of surrounding hematoma to gestational sac is a significant predictor of pregnancy loss, with a cut-off value of 35.5% determining the possibility of complication with 70% sensitivity and 75% specificity 3.
  • Non-specific pelvic pain is more common in women with pregnancy loss, but its presence does not significantly affect pregnancy outcome 3.
  • The use of low-dose aspirin is associated with an increased risk of placental abruption and postpartum hemorrhage, with an adjusted odds ratio of 1.44 and 1.21, respectively 4.
  • Low-molecular-weight heparin in addition to aspirin may reduce the prevalence of pre-eclampsia and small-for-gestational-age neonates in women with a history of pre-eclampsia 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Propensity score analysis of low-dose aspirin and bleeding complications in pregnancy.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2024

Research

Prevention of pre-eclampsia by low-molecular-weight heparin in addition to aspirin: a meta-analysis.

Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2016

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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