If a newborn boy is ill on the eighth day, when a Brit Milah is normally performed, he does not undergo circumcision until he recovers. When precisely should the circumcision be performed in such a case?
The Shulchan Aruch rules (Yoreh Dei'a, 262:2) that if the child was ill on the eighth day, the circumcision is performed exactly seven days after his recovery, meaning, seven days after the physician determines that he is fit for circumcision.
This ruling, however, applies only to illnesses that affect and potentially endanger the infant's entire body, such as a fever or infection, or if the child must be kept in an incubator or receive a blood transfusion. In all these cases, due to the gravity of the infant's condition, we wait seven days after the infant receives a clean bill of health before performing the Brit Milah. (Soba Semahot, Helek 2, page 120.)
However, in cases of normal medical conditions that warrant delaying the Brit Milah, or of conditions that affect only one isolated part of the body, the circumcision may and should be performed immediately when the physician or Mohel determines that the child is healthy. For example, Rabbi Moshe Feinstein (Russia-New York, 1895-1986) ruled that if a newborn could not undergo circumcision on the eighth day because of low weight, and all that is required is for him to reach the proper weight, the Brit Milah is performed immediately when he reaches that weight. Similarly, if an infant is jaundiced, a very common condition among newborns, the Brit Milah should be conducted immediately once the bilirubin count drops to an acceptable level. This applies as well to an infant that does not suck properly and therefore cannot nurse, or that suffers from some defect in his pallet or tear duct, or a broken bone. In all these situations, the Brit should be performed immediately once the physician determines that the child is physically fit for circumcision. (Soba Semahot, Helek 2, pages 120-121.)
Needless to say, in all such cases one should consult with a competent Rabbi or Mohel.
When a Brit Milah is delayed and must be performed after the child's eighth day, it may not be performed on Thursday, Friday or Shabbat. Therefore, if the child becomes ready for circumcision (based on the guidelines discussed above) on one of these days, the Brit should be held on Sunday. (Soba Semahot, Helek 2, page 137.)
Summary: If a child's circumcision is delayed beyond the eighth day due to a fever, infection or some other serious illness affecting the entire body, the Brit is performed precisely seven days after the physician determines that he is physically fit for circumcision. If the Brit was delayed due to normal conditions such as jaundice or low weight, or due to an ailment affecting one specific part of the body, such as a fracture, it is performed immediately when the child is determined to be healthy. However, whenever a child is circumcised after the eighth day, the Brit may not be held on a Thursday, Friday or Shabbat.
