On FamilySearch, I found the following index to multiple books of vital records from Mogilev:
https://www.familysearch.org/search/catalog/708776?availability=Family%20History%20Library

The records are handwritten in Russian and Hebrew, and the microfilm images can be viewed online.  Image quality is faint and hard to read.

The absence of a child's name from the birth record index is likely to indicate a male who died before the age of one week.