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Amnioreduction Periprocedural Care

  • Author: Jenny E Halfhill, DO; Chief Editor: Carl V Smith, MD  more...
Updated: Feb 04, 2015

Patient Education and Consent

Written consent must be obtained from the patient. A clear summary of the risks, benefits, and alternatives must be provided, and the patient must voice understanding. In particular, risks such as preterm labor (and delivery), infection (eg, chorioamnionitis), placental abruption (bleeding), and fetal death must be explained to the patient.[6] An overall risk of 1.5-3.1% is noted in the literature.[7]


Preprocedural Planning

Routine subjective comfort measures should be used. If the pregnancy is viable, resources that would allow cesarean delivery if necessary should be immediately available. This preparation should include placing the patient on nil per os (NPO) and, potentially, administering antenatal corticosteroids as indicated and appropriate according to standard guidelines.[8] Anesthesia standby may be appropriate (for supports ranging from intravenous [IV] sedation to general anesthesia).



The procedure may be performed manually or with vacuum-assisted devices (eg, vacuum tubing and vacuum bottles). The materials necessary for amnioreduction include the following[9] :

  • Several 500-mL evacuation containers
  • Amniocentesis tray
  • Hard-walled arterial tubing with a 3-way stopcock
  • Specimen collection containers
  • Needles, typically 18 or 20 gauge
  • Syringe, 50 mL
  • Sterile cover sheet
  • Local anesthetic
  • Sterile gloves and towels
  • Fetal monitoring equipment
  • Ultrasound machine

Patient Preparation

Maternal sedation with benzodiazepines may reduce movement and improve comfort.[6] A local anesthetic (eg, lidocaine) is injected into the skin and subcutaneous tissue to reduce the pain associated with needle insertion.

Positioning should be optimized to permit prolonged maintenance of a stable surgical field. Proper positioning of the patient and the draining mechanisms will decrease complications.[6] The patient should be supine in a left lateral tilt position to reduce compression of the vena cava, and support pillows should be used to enhance maternal comfort.

Contributor Information and Disclosures

Jenny E Halfhill, DO Resident Physician, Department of Obstetrics and Gynecology, Western Pennsylvania Hospital

Jenny E Halfhill, DO is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Osteopathic Association

Disclosure: Nothing to disclose.


Ronald Lee Thomas, MD Associate Professor, Department of Obstetrics and Gynecology, Drexel University College of Medicine; Director, Division of Maternal-Fetal Medicine and Obstetrical Services, Director, Department of Obstetric/Gynecological Ultrasound, Allegheny General Hospital, West Penn Allegheny Health System

Ronald Lee Thomas, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, Pennsylvania Medical Society, Society for Maternal-Fetal Medicine, Allegheny County Medical Society, Johns Hopkins Medical and Surgical Association

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Carl V Smith, MD The Distinguished Chris J and Marie A Olson Chair of Obstetrics and Gynecology, Professor, Department of Obstetrics and Gynecology, Senior Associate Dean for Clinical Affairs, University of Nebraska Medical Center

Carl V Smith, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, Association of Professors of Gynecology and Obstetrics, Central Association of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, Council of University Chairs of Obstetrics and Gynecology, Nebraska Medical Association

Disclosure: Nothing to disclose.

  1. Coviello D, Bonati F, Montefusco SM, Mastromatteo C, Fabietti I, Rustico M. Amnioreduction. Acta Bio Medica Ateneo Parmense. 2004. 75:31-33.

  2. Piantelli G, Bedocchi L, Cavicchioni O, et al. Amnioreduction for treatment of severe polyhydramnios. Acta Bio Medica Ateneo Parmense. 2004. 75:56-58.

  3. Fisk NM, Tannirandorn Y, Nicolini U, Talbert DG, Rodeck GH. Amniotic pressure in disorders of amniotic fluid volume. Obstet Gynecol. 1990. 76:210-214.

  4. Queenan JT, Gadow EC. Polyhydramnios. Am J Obstet Gynecol. 1970. 108:349-355.

  5. Makino Y, Makino I, Tsujioka H, Kawarabayashi T. Amnioreduction in patients with bulging prolapsed membranes out of the cervix and vaginal orifice in cervical cerclage. J Perinat Med. 2004. 32.

  6. Jan E Dickinson. Amnioreduction therapy for twin-twin transfusion syndrome. Quintero RA. Twin-Twin Transfusion Syndrome. Informa Healthcare; 2007. 891-97.

  7. Leung W, Jouannic J, Hyett J, Rodeck C, Jauniaux E. Procedure-related complications of rapid amniodrainage in the treatment of polyhydramnios. Ultrasound Obstet Gynecol. 2003. 23:154-158.

  8. ACOG Committee Opinion No. 402: Antenatal corticosteroid therapy for fetal maturation. Obstet Gynecol. 2008 Mar. 111(3):805-7. [Medline].

  9. Beloosesky R, Ross MG. Polyhydramnios [database online]. UpToDate. Accessed December 17, 2011:

  10. Dickinson JE, Tjioe YY, Jude E, Kirk D, Franke M, Nathan E. Amnioreduction in the management of polyhydramnios complicating singleton pregnancies. Am J Obstet Gynecol. 2014 Oct. 211(4):434.e1-7. [Medline].

  11. Chai H, Fang Q, Huang X, Zhou Y, Luo Y. Prenatal management and outcomes in mirror syndrome associated with twin-twin transfusion syndrome. Prenat Diagn. 2014 Jul 9. [Medline].

  12. Roberts D, Neilson JP, Kilby MD, Gates S. Interventions for the treatment of twin-twin transfusion syndrome. Cochrane Database Syst Rev. 2014 Jan 30. 1:CD002073. [Medline].

Image of ultrasound-guided amnioreduction. The sonogram shows needle placement for amnioreduction in a case of polyhydramnios.
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