LAUSR

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 Fof phocomelia, a severe, congenital malformation of deformed or rudimentary limbs, occurred from in utero fetal exposure to thalidomide after its administration to pregnant mothers to treat nausea and vomiting or anxiety during the first trimester of pregnancy, even though thalidomide had been shown to be safe and efficacious in both nonpregnant laboratory animals and nonpregnant subjects enrolled in clinical trials. The medical community therefore codified through the United States Food and Drug Administration Drug Regulation Act of 1962 that the safety of drugs during pregnancy cannot be extrapolated from clinical studies in nonpregnant patients, but must be demonstrated directly by clinical studies in pregnant patients. This principle was extended subsequently to determine the risks of endoscopy during pregnancy to the pregnant patient and the fetus in utero by specific clinical studies on pregnant patients undergoing endoscopy. Although studies on endoscopy in nonpregnant patients normally require only a few days of postprocedure followup to assess endoscopy safety, studies on endoscopy in pregnant patients must follow the pregnancy until after delivery, up to 9 months after the endoscopy, to assess the health of the newborn, and perhaps require even further follow-up of the newborn for several years thereafter to detect subtle neuropsychiatric deficits that may not manifest until years after birth. The baseline risk of poor fetal outcomes is small, requiring the analysis of a large study population of pregnant patients undergoing endoscopy to provide robust statistical power to exclude that relatively small increases in clinically devastating, poor fetal outcomes, such as major congenital malformations, are statistically significantly higher than the baseline rate. Indications for endoscopy are common during pregnancy. For example, esophagogastroduodenoscopy (EGD) is commonly indicated during pregnancy for abdominal pain, upper gastrointestinal bleeding, dysphagia, and abnormal radiographic findings; and uncommonly indicated during pregnancy for pyrosis, suspected gastroesophageal reflux, dyspepsia, or nausea and vomiting. About 2% of the female population or about 1% of the entire population (including males) is pregnant at any given time. Given that 18.4