生後 (せいご)post-natal; since birth

生後, its kanji, and other words that share them.Open this graph

Kanji in 生後

学生がくせいstudent (esp. a university student)
生活せいかつliving; life (one's daily existence)
生産せいさんproduction; manufacture
人生じんせい(human) life (i.e. conception to death)
先生せんせいteacher; instructor
厚生省こうせいしょうMinistry of Health and Welfare (now Ministry of Health, Labour and Welfare)
年生ねんせいpupil in ... year; student in ... year
新生しんせいrebirth; new birth
今後こんごfrom now on; hereafter
午後ごごafternoon; p.m.
後あとbehind; rear
戦後せんごpostwar period; period after Second World War
最後さいごend; conclusion
後半こうはんsecond half; latter half
直後ちょくごimmediately following
後援こうえんsupport; backing

See how 生後 connects to the rest of Japanese.