Common Cases
10. It is impossible to list all the situations and types of illnesses that require one to consider if and when to perform a bris. Nevertheless, we will mention some of the more common examples to bring awareness to common shailos so that people know to consult a doctor and rav when necessary. One should always consult a doctor and a rav in any other situation or illness, ל"ע .
Temperature
11. High temperature. An infant with a fever must wait seven full days after the fever subsides (שו''ע רס''ב ס''ב ) to under 38°C/100.4°F.
12. Low temperature. Similarly, an infant with a temperature below 36°C/96.8°F is considered ill and must wait seven full days (אוצר הברית ח''ג עמ' קל''ט ).
Low Weight
13. A newborn with a low birth weight may get a bris once the doctors permit it. Usually an infant can get a bris if he was born after week 38 of gestation and has gotten back to his birth weight. Babies usually lose some weight in their first days and then begin to gain weight. Once an infant begins to gain weight and is eating properly, he may get a bris.
14. If an infant is born prior to week 38 and has a low birth weight, one should consult a doctor to make sure the infant is considered healthy. If the infant is eating well and gaining weight, he may get a bris when he weighs about 2.3 kg/5 lb to fulfill the mitzva of bris milah on the eighth day. However, some rule that if it is already a delayed bris, they should wait until he is about 2.5 kg/5.5 lb or close to it.
15. Twins. When twins are born and they are small, a doctor should be consulted to determine if they may get a bris, but the fact that they are twins can be factored in. Thus, they may be considered fully developed and strong even if they are below average weight. A bris can be done even if they weigh around 2.1 kg/4.6 lb (מו''ר הג''ר מאיר בראנדסדארפער ).
Weak
16. If an infant does not have a specific illness, but he seems weak, e.g., he nurses weakly, is overly sleepy, has weak reflexes or the like, or has any other evidence of general weakness, a bris should not be performed without consulting a doctor. Once the infant gains strength, he may get a bris right away and does not need to wait seven days (ב''י, שו''ת חת''ס ח''ו סי' ס''ד, שו''ת דובב מישרים סי' ס''א, תשובות והנהגות ח''א סי' תקצ''א ).
Inflammation Around the Eyes
17. If an infant has eye pain but not a serious illness that weakens his whole body, he can have a bris as soon as he gets well. However, if he has serious eye pain that weakens his whole body, he must wait seven full days after he gets well (שו''ע סי' רס''ב ס''ב ).
18. Eye discharge, “sticky eye.” It is common for newborns to have some whitish-yellowish discharge around the eye, usually caused by a blocked tear duct. It is usually not inflammation or infection, so it is not considered an illness at all. As long as it appears minor to the mohel, he may do the bris right away (מו''ר הג''ר מאיר בראנדסדארפער ).
19. Eye infection. However, if there is thick, yellowish-greenish discharge, a lot of discharge, swelling around the eye, redness in the eye, or red, swollen eyelids and it seems there is real illness in the eye, one should consult a doctor to determine whether antibiotics are necessary, and a rav to determine if the bris should be performed as soon as the infant is well or if they must wait seven additional full days.
