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LETTERS

Gastric suction at birth: Not an innocent bystander

To the Editor:In their scholarly overview of functional bowel disorders

(FBD), Drs Di Lorenzo and Saps discuss many factors thatcould be involved in the development of FBD.1 These highlyrelevant factors, including the list of early life events affectingthe stress response, are not related to the findings reported inour epidemiologic study.2 These comments seem to discounttwo important scientific principles relevant for the assessmentof our findings.

First, a cause must precede an outcome; studies that failto account for proximate causal factors on the subsequentoccurrence of a disease will have a limited ability to examinethe effects of other factors occurring later in the patient’s life.Second, a search for other confounding factors that couldexplain our results must necessarily be limited to the briefperiod after birth during which gastric suctioning occurred.Whatever happens before or after this event will modify therelationship but not explain it.

During this study period, gastric suctioning wascommonly performed to prevent aspiration of gastric contents.This clinical practice occurred routinely in some hospitals andnot in others. Prophylactic gastric suctioning at birth wasperformed routinely in the hospital selected for this study.

Other neonatal variables may include clinical events thatoccurred after the gastric suctioning at birth. Therefore, theseevents cannot have any influence on the suctioning performedimmediately after birth, thus making their confoundingeffects impossible. Conversely, if gastric suctioning at birthleads to other outcomes (eg, increased length of stay in thehospital, delayed onset of feeding, or longer time to reach fullenteral feeding), then their effects would contribute to themechanism by which the gastric suctioning exerts its long-term effects.

The editorial is correct in pointing out the limitednumbers of cases and controls, a weakness that was identifiedin our discussion. Nevertheless, if there is a causal relationshipbetween gastric suctioning and FBD, such hospital practiceswould lead to a higher incidence of FBD within populationsborn at these hospitals compared with those born at otherhospitals. Indeed, of greatest concern is our finding that FBDoccurred more commonly among the 1110 subjects born at theSOS hospital (9.5%) compared with the general population(3.4%, P < .000001).2

We also had a gut feeling that ‘‘Gastric suction is sucha common and ‘benign’ intervention that is strikes us as anunlikely culprit for any long-term consequence.’’ Unfor-tunately, the practice of neonatology is littered with ‘‘benign’’interventions that ultimately proved to be ineffective orharmful. Who would have thought that brief, early separation

14 Letters

from the mother would have such profound effects onmaternal-infant bonding? Does it seem plausible that merelygiving a sedative to the mother at delivery would increase thelikelihood of her infant developing drug addiction as anadult?3-7 If brief exposure to a sedative at birth increasesa child’s chances of becoming a drug addict, is it not plausiblethat traumatic events at birth may have other, less severe long-term consequences?

Contrary to the assertion by Drs Di Lorenzo and Saps,the biologic plausibility of our results is supported by multiplelines of clinical and experimental evidence.8-11 Gastricsuctioning at birth in term neonates is not an innocentbystander.

K.J.S. Anand, MBBS, DPhilBertil Jacobson, MD, PhD

Richard W. Hall, MDYMPD1063

10.1016/j.jpeds.2004.06.057

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or innocent bystander? J Pediatr 2004;144:417-20.

2. Anand KJS, Runeson B, Jacobson B. Gastric suction at birth associated

with long-term risk for functional intestinal disorders in later life. J Pediatr

2004;144:449-54.

3. Jacobson B, Nyberg K, Eklund G, Bygdeman M, Rydberg U. Obstetric

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4. Jacobson B, Nyberg K, Gronbladh L, Eklund G, BygdemanM, Rydberg

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7. Nyberg K, Buka SL, Lipsitt LP. Perinatal medication as a potential risk

factor for adult drug abuse in a North American cohort. Epidemiology 2000;

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8. Coutinho SV, Plotsky PM, Sablad M, Miller JC, Zhou H, Bayati AI, et

al. Neonatal maternal separation alters stress-induced responses to viscer-

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9. Mayer EA, Collins SM. Evolving pathophysiologic models

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10. Al-Chaer ED, Kawasaki M, Pasricha PJ. A new model of chronic

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11. Ross MG, El-Haddad M, DeSai M, Gayle D, Beall MH.

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The Journal of Pediatrics � November 2004