What to do about polyhyarmnios (excess amniotic fluid)?

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From the Guidelines

If you have more amniotic fluid than normal (a condition called polyhydramnios), you should consult with your healthcare provider promptly and consider amnioreduction as a potential treatment option, as it has been associated with average survival rates of 50% in cases of twin-twin transfusion syndrome 1. The management of polyhydramnios depends on the severity of the condition and the presence of any underlying causes.

  • For mild cases, close monitoring with regular ultrasounds may be all that's needed.
  • For moderate to severe cases, medications like indomethacin might be prescribed to reduce fluid production, though this is usually only used before 32 weeks of pregnancy due to potential fetal side effects.
  • In some cases, amnioreduction (a procedure to remove excess fluid) might be necessary, as it has been shown to reduce the risks associated with polyhydramnios, such as preterm labor and placental abruption 1. It's essential to investigate potential causes of polyhydramnios, which could include gestational diabetes, fetal anomalies, or infections, and manage any underlying conditions to prevent complications. Throughout this process, it's crucial to watch for warning signs like premature contractions, difficulty breathing, or significant abdominal discomfort, which warrant immediate medical attention, as polyhydramnios increases risks of preterm labor, placental abruption, and umbilical cord prolapse 1. The use of NSAIDs, such as indomethacin, should be considered with caution due to the potential risks to the fetus, including fetal ductus arteriosus constriction, and close monitoring with fetal echocardiography is mandatory in all cases of maternal NSAID therapy 1. Ultimately, the goal of managing polyhydramnios is to reduce the risks associated with the condition and ensure the best possible outcome for both the mother and the fetus.

From the Research

Definition and Causes of Polyhydramnios

Polyhydramnios is an abnormal increase in the volume of amniotic fluid, which can be caused by various factors, including:

  • Maternal diabetes mellitus
  • Fetal anomalies
  • Congenital infection
  • Alloimmunization
  • Idiopathic causes

Diagnosis of Polyhydramnios

The diagnosis of polyhydramnios is typically made by ultrasound examination, with a deepest vertical pocket of ≥8 cm or an amniotic fluid index of ≥24 cm being indicative of the condition 2.

Management of Polyhydramnios

The management of polyhydramnios depends on the underlying cause and severity of the condition. The following options may be considered:

  • Amnioreduction: a procedure to remove excess amniotic fluid, which may be considered for severe maternal discomfort, dyspnea, or both in the setting of severe polyhydramnios 2
  • Indomethacin therapy: a non-steroidal anti-inflammatory drug (NSAID) that can help reduce amniotic fluid volume, although its use is not recommended for the sole purpose of decreasing amniotic fluid in the setting of polyhydramnios 2
  • Antenatal fetal surveillance: may not be required for mild idiopathic polyhydramnios, but may be necessary for more severe cases or those with underlying fetal anomalies 2
  • Delivery: women with severe polyhydramnios should deliver at a tertiary center due to the significant possibility of fetal anomalies, and labor should be allowed to occur spontaneously at term for women with mild idiopathic polyhydramnios 2

Treatment with Indomethacin

Indomethacin therapy has been shown to be effective in reducing amniotic fluid volume in cases of polyhydramnios, with studies demonstrating significant improvements in symptoms and outcomes 3, 4, 5. However, the use of indomethacin should be carefully monitored, as it can cause adverse effects such as oligohydramnios and fetal ductal constriction 3. The optimal dose of indomethacin is unknown, but a dose of 25 mg every 6 hours has been suggested 3.

Other Considerations

Other considerations in the management of polyhydramnios include:

  • Fetal echocardiography: should be considered in the first 24 hours after indomethacin therapy has been initiated and weekly thereafter to monitor for fetal ductal constriction 3
  • Ultrasound assessment of amniotic fluid volume: should be done once or twice weekly to monitor the effectiveness of treatment and potential adverse effects 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

SMFM Consult Series #46: Evaluation and management of polyhydramnios.

American journal of obstetrics and gynecology, 2018

Research

Indomethacin therapy in the treatment of symptomatic polyhydramnios.

Clinical obstetrics and gynecology, 1991

Research

Treatment of polyhydramnios with prostaglandin synthetase inhibitor (indomethacin).

American journal of obstetrics and gynecology, 1987

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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