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  • Amniocentesis

  • Ankle-Brachial Index

  • Audiometry and Tympanometry

  • Bone Marrow Aspiration and Biopsy

  • Capsule Endoscopy

  • Cardiac Monitor, Implantable

  • Cardiac Monitor, External (Holter)

  • Cardiac Stress Testing

  • Chorionic Villus Sampling (CVS)

  • Colposcopy

  • Coronary Artery Calcium Scoring

  • Cystoscopy

  • Electroencephalogram (EEG)

  • Electromyography (EMG) and Nerve Conduction Studies (NCV)

  • Endoscopic Ultrasound

  • Esophageal Manometry

  • Fetal Heart Rate Monitoring

  • Loop Electrosurgical Excision Procedure (LEEP)

  • Polysomnography

  • Urodynamics

A variety of diagnostic testing, both invasive and noninvasive, is performed in the inpatient and outpatient settings. This is a brief overview of some of the specialized diagnostic testing commonly used in daily patient care. Note that specific procedure details and preparations can vary by facility and by provider.

Chapter update by Babak Abai, MD, FACS, Mark B. Chaskes, MD, MBA, Stephanie Chen, MD, Rebecca Chiffer, MD, Mitchell Conn, MD, Tricia Gomella, MD, Ritu Grewal, MD, Colin Huntley MD, Kathryn Landers, MD, Yair Lev, MD, Aaron Martin, MD, and, Alana Murphy, MD, FACS, Allyson Pickard, MD, Michael Sperling, MD, William Tester, MD, FACP, Stephanie Thomas, MD


Description: A spinal needle is inserted transabdominally into the amniotic sac of a developing fetus under ultrasound guidance. Amniotic fluid is aspirated and sent to the laboratory for analysis. This procedure is typically performed in an ultrasound suite or on labor and delivery. Amniotic fluid can be analyzed for prenatal diagnosis of karyotypic abnormalities, genetic disorders (for which testing is available), fetal blood type and hemoglobinopathies, fetal lung maturity, and monitoring the degree of isoimmunization by measurement of the content of bilirubin in the fluid, and for the diagnosis of chorioamnionitis. Testing for karyotypic abnormalities is usually done at 15- to 20-wk gestation. Amniocentesis also provides a useful tool later in pregnancy, is low risk, and can be used for diagnosis of intraamniotic inflammation and infection as a risk factor for preterm labor and adverse outcome.

Common Indications: Diagnosis of fetal genetic abnormalities; women at an increased risk of aneuploidy or genetic abnormalities (either by history or abnormal first- or second-trimester screening tests) and fetal structural abnormalities identified on ultrasound; and evaluation for intraamniotic infection when clinical findings are not sufficient to guide management. The American College of Obstetricians and Gynecologists’ policy is that invasive diagnostic testing should be available to all women, regardless of age or risk.

General Preparation: Informed consent, counseling on the risks and limitations of the procedure; confirmation of gestational age and placental location and selection of a needle insertion site using ultrasound; antiseptic technique; local anesthetic is usually not necessary.

Potential Complications: Intraamniotic infection (<0.1%); fetal loss (<0.5%); risk of vertical transmission of maternal infection (HIV, hepatitis B and C).

Notes: Typically performed at 15-wk gestation or later. Early amniocentesis (before 15 wk) is generally not recommended because it is associated with a significantly higher rate of fetal loss, preterm premature rupture of membranes, ...

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