Expectant Management Outperforms LMWH in Umbilical Artery Thrombosis, Study Finds

Umbilical artery thrombosis is a rare but potentially life-threatening pregnancy complication caused by clot formation that obstructs blood flow through the umbilical artery. This can severely limit the fetus's oxygen and nutrient supply, increasing the risk of fetal distress, growth restriction, or stillbirth. Due to its rarity, there is no clear consensus on standardized treatment. Diagnosis usually involves a Doppler ultrasound and pathological confirmation, and management aims to prolong gestation and improve outcomes. While LMWH is sometimes used, its benefits over expectant management remain unclear.

Against the above background, Peng Zhao, Department of Obstetrics, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, China, and colleagues conducted the study to evaluate the therapeutic value of LMWH in managing UAT during pregnancy.

For this purpose, the researchers conducted a retrospective study spanning from January 2013 to December 2023 involving singleton pregnant women diagnosed with umbilical artery thrombosis. The participants were divided into two groups: the experimental group received low-molecular-weight heparin as part of anticoagulation therapy during pregnancy, while the expectant group received standard prenatal care without targeted intervention for UAT.

The study revealed the following findings:

• Birth weight was significantly higher in the expectant group than in the experimental group (2434.40 ± 770.20 g vs. 1874.46 ± 717.83 g).
• The incidence of births before 34 weeks was significantly lower in the expectant group compared to the experimental group (42.24% vs. 82.75%).
• Gestational age at birth was higher in the expectant group than in the experimental group (35.32 ± 3.89 weeks vs. 33.59 ± 4.17 weeks), though this difference was not statistically significant.
• Multi-factor ANOVA showed a statistically significant effect of anticoagulation therapy on birth weight (F = 4.479).
• Gestational age at birth also had a statistically significant effect on birth weight (F = 179.110).
• The relationship between birth weight, anticoagulation therapy, and gestational age at birth was represented by the following equation:
• Birth weight = −3314.782 – 256.106 × (anticoagulation therapy: 1 if yes, 0 if no) + 161.858 × gestational age at birth.

The study offers important insights into managing umbilical artery thrombosis, indicating that expectant therapy may provide substantial advantages over experimental treatment with low-molecular-weight heparin.

"These findings hold potential value for guiding clinical decision-making and highlight the need for further research to refine treatment strategies for this rare but serious pregnancy complication," the authors concluded.

Reference:

Zhao, P., Lu, Y., Liu, S., Zhang, L., Chen, C., & Yang, X. (2025). Evaluating the efficacy of low-molecular-weight heparin in managing umbilical artery thrombosis during pregnancy: Does it offer therapeutic benefits? Frontiers in Medicine, 12, 1540685. https://doi.org/10.3389/fmed.2025.1540685