Pregnant & Lactating Women

Indications for endoscopy in pregnancy
Pre-procedure evaluation
Maternal and fetal risks
Physiologic changes in pregnancy
Pharmacologic considerations
Monitoring considerations
Lactation

An estimated 20,000 pregnant women in the United States undergo a gastrointestinal endoscopic procedure each year.  It is not definitively known whether exposure to anesthesia or sedation drugs during pregnancy places either the mother or fetus at additional risk for complications.

Indications for endoscopy in pregnancy

Endoscopy should be performed during pregnancy only when the indication for the procedure is clear and less invasive diagnostic or therapeutic modalities do not exist. In addition, whenever possible the procedure should be postponed until the second trimester. According to the American Society for Gastrointestinal Endoscopy (ASGE) Guidelines for Endoscopy in Pregnant and Lactating Women, the indications to perform gastroendoscopy during pregnancy include:

  • Significant or continued gastrointestinal bleeding
  • Severe or refractory nausea and vomiting or abdominal pain
  • Dysphagia or odynophagia
  • Severe diarrhea with unknown cause
  • Biliary pancreatitis, choledocholithiasis, or cholangitis
  • Biliary or pancreatic ductal injury

Pre-procedure Evaluation

As part of the general pre-procedure assessment, the clinician should question any female patient of childbearing age as to whether or not she may be pregnant. History and physical examination may be insufficient for identification of early pregnancy. A pregnancy test should be ordered if a woman is unsure of her pregnancy status or the clinician suspects she may be pregnant.  One study found that the incidence of unrecognized true positive pregnancies on the day of a surgical procedure was 4 of 2588, or 0.15%.  Should a spontaneous abortion occur after gastrointestinal endoscopy, or the baby be born with a congenital anomaly, the patient may attribute this to the procedure itself or drugs administered.

If a patient is pregnant, the informed consent process should include information about fetal risks associated with anesthesia as well as the procedure. Pre-procedure preparation for a pregnant patient should include obstetric input into the planning process. Consultation with a member of the anesthesia staff is also recommended. Obstetric support should be available during the procedure in the event of a pregnancy-related complication. In addition, fetal well-being should be confirmed before beginning the procedure and reevaluated as soon as possible after its completion.

Maternal and fetal risks

Both mother and fetus face potential risks from endoscopic sedation. These risks vary depending on the trimester of pregnancy. Pregnancy causes a number of anatomic and physiologic changes which impact delivery of sedation during endoscopy.

The nasal and mucous membranes of pregnant women become engorged leading to a narrowing of the airway. In addition, there is a compensatory increase in minute ventilation in order to meet maternal and fetal oxygen demands. However, lung capacity decreases as the diaphragm becomes elevated.

Hemodynamic changes occur during pregnancy as well. Normal heart rate increases to 90 to 100 beats per minute. Cardiac output increases 40%. Systolic blood pressure can drop. Pregnant women often cannot tolerate the supine position, especially after 30 weeks gestation, due to reduced blood pressure from the weight of the uterus. Women are encouraged to maintain left uterine displacement either by elevation of the right hip or by positioning themselves on their sides. 

There is also an increase in blood volume during pregnancy of up to 40% above normal during the later stages of pregnancy.  The majority of this increase is in plasma volume. During sedation for GI procedures, increased extracellular fluid volume and vascular engorgement in pregnant patients means that extra care is needed to retain a patent airway.

Physiologic Changes in Pregnancy

   
Cardiovascular Pulmonary Gastrointestinal
  • Increased oxygen consumption
  • Decreased vascular resistance
  • Increased cardiac output
  • Increased blood volume
  • Edema of upper airway and mucous membranes
  • Increased risk of nosebleed from insertion of nasal airway
  • Reduced lung capacity as fetus enlarges increasing risk of maternal hypoxemia
  • Decreased gastrointestinal motility
  • Decreased food absorption
  • Increased gastric acidity
  • Decreased lower esophageal sphincter tone

In second and third trimesters:

  • Compression of vena cava and aorta by weight of uterus. This can lead to decreased venous pressure resulting in maternal tachycardia and fetal distress.   
   

Pharmacologic considerations

Sedative and analgesic agents should always be used in the smallest effective dose to minimize the potential risk of teratogenic effects. The greatest risk to the fetus occurs during the first trimester when fetal development is most vulnerable to the potential teratogenic effects of a medication. There is also a risk that administering sedative medications close to the time of delivery will lead to sedation in the newborn.  Dosing guidelines are similar for pregnant and non-pregnant women. However, the increased circulating volume of blood that occurs in pregnancy will result in lower blood concentrations of water soluble drugs, such as meperidine. This may slow the onset of action. 

The U.S. Food and Drug Administration categorizes drugs into five groups based on the evidence of their safety during pregnancy. (FDA Drug Safety Categories). However, these categories are of limited value for determining the safety of one-time use. Therefore, consultation with an obstetrician and/or an anesthesiologist regarding medication use during pregnancy should be considered. There are no category A drugs used for endoscopy sedation. In general, category B and when necessary, category C drugs are recommended. For procedural sedation during pregnancy, meperidine alone is preferred, (category B). If required, meperidine can be followed by small doses of midazolam (category D). In cases where a benzodiazepine is used, midazolam should be chosen over diazepam. However, midazolam should be avoided if possible during the first trimester.

For most upper and lower gastrointestinal procedures, the level of sedation should be anxiolysis or moderate sedation. Sedation should be administered by an anesthesiologist in the case of a high risk pregnancy or if deep sedation is required.

Safety in Pregnancy of Commonly Used Medications for Endoscopic Sedation

   
Drug FDA Category Comments
Meperidine B
  • Does not appear to be teratogenic in two major studies.
  • Preferred over fentanyl and morphine
  •  Fentanyl C
  • Appears to be safe in humans when given in low doses typical for endoscopy.
  • Not teratogenic but was embryocidal in rats.
  • Rapid onset of action and shorter recovery time than meperidine.
  •  Naloxone B
  • Does not appear to be teratogenic.
  • Contradicted in mothers who are dependent on opiates because it can precipice opiate-withdrawal symptoms.
  • To be used only in cases of respiratory depression, hypotension, or unresponsiveness under close monitoring.
  • Risk of resedation as drug is metabolized.
  •  Benzodiazepines D
  • Diazepam should not be used for sedation in pregnant women.
  • Sustained use of diazepam in pregnancy has been linked to cleft palate and neurobehavioral disorders.
  • Midazolam has not been reported to be associated with congenital abnormalities.
  • Midazolam is the preferred benzodiazepine when meperidine is inadequate.
  • Midazolam use in the first trimester should be avoided.
  •  Flumazenil C
  • Little is known about safety profile.
  • Not teratogenic but produces neurobehavioral changes in male rats exposed in utero.
  •  Propofol B
  • Safety in first trimester has not been established.
  • When administered to a pregnant patient, it is recommended that this drug be administered by an anesthesiologist due to narrow therapeutic index and need for close monitoring.
  •  Glucagon B Not contraindicated in pregnancy
    Lidocaine B  
  • No  fetal abnormalities associated with drug in one study.
  • Suggested that patient gargle and spit out the drug instead of swallowing.
  • Monitoring considerations

    Standard procedures for physiologic monitoring during endoscopic sedation apply to procedures performed during pregnancy. Fetal monitoring should be considered on a case by case basis depending on the needs of the mother and fetus. This should be done under the advisement of the patient's obstetrician. In addition, the endoscopy team should be aware of the certain pregnancy-related risks and monitor the patient accordingly.

    • Airway compromise. Pregnant women are at higher risk of having a difficult to manage airway. For example, a pregnant woman with engorged nasopharyngeal and larynx tissues may require a smaller endotracheal tube than normal so it is important to ensure that the necessary supplies are available. Supplemental oxygen should be readily available and utilized early. Hypoxia carries risks for both the mother and the fetus, and can precipitate contractions.
    • Dehydration. Ensuring adequate volume replacement for the patient who has been kept NPO is imperative to prevent dehydration and the onset of contractions.
    • Positioning. In late pregnancy, women should be placed in the lateral decubitus, or right side up, position during and after the procedure to ensure adequate blood return to the heart.

    Lactation

    The sensitivity and risks of sedation and analgesia in lactating women is similar to that of other adults. The primary concern related to sedation when a woman is breast feeding is the risk of transferring drugs to the infant through the breast milk.  In cases where the medication may be harmful to the infant, the woman should be advised to pump her breast milk and discard it, with the timing dependent upon the agent of concern.

    Lactation Guidelines for Commonly Used Drugs for Endoscopic Sedation

     

    Drug

    Recommendations/Comments

    Meperidine

  • Concentrated in breast milk up to 24 hours after administration.
  • May have neurobehavioral effects on the breast-fed infant.
  • Use fentanyl as an alternative if possible.
  • Midazolam
  • Effects of drug on infant unknown.
  • Infants should not be breast-fed for at least 4 hours after maternal midazolam administration.
  • Fentanyl
  • Breast-feeding may be continued after maternal fentanyl administration.
  • Excretion in breast milk but in very low concentrations for up to 10 hours after administration.
  • Fentanyl is preferred over meperidine in lactating women.
  • Propofol
  • Excreted in breast milk with maximum concentrations 4 to 5 hours after administration.
  • Effects of small doses on infant are unknown.
  • Continued breast-feeding after maternal propofol exposure is not recommended although the period of prohibition has not been determined.
  • Naloxone and flumazenil
  • Safety of these drugs in this setting is unknown
  •  


    Sources

    American Society for Gastrointestinal Endoscopy, Guidelines for Endoscopy in Pregnant and Lactating Women, Gastrointestinal Endoscopy. Vol. 61, No. 3: 2005.

    Gilinsky NH, Muthunayagam N. Gastrointestinal endoscopy in pregnant and lactating women: emerging standard of care to guide decision-making. Obstetrical & Gynecological Survey 2006;61:791-799.

    Kost M. Moderate Sedation/Analgesia: Core Competencies for Practice, 2nd Ed. St. Louis, MO: Saunders, St. Louis; 2004: 59.

    Lazear SE. Course 1055: Moderate sedation/analgesia. CME resources. P. 44.

    Richard L. Kahn, Maureen A. Stanton, Sarani Tong-Ngork, Gregory A. Liguori, Chris R. Edmonds, and David S. Levine. One-Year Experience with Day-of-Surgery Pregnancy Testing Before Elective Orthopedic Procedures. Anesth Analg 2008 106: 1127-1131

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