Irish Pregnancy?

So a friend told me about Irish pennants--what she called the loose threads that hang off one's clothing

Today I learned about Irish pregnancy. A woman who works at BI Needham told me her daughter has a 6-month old baby.  And  then the daughter got pregnant again! She called it an Irish pregnancy.

Sounds like the luck o' the Irish!

p.s.  No overly Irish names for our kid. No Finnns, Seamus's, or Declans. Not that there's anything wrong with those names. We're thinking more Swedish:
Lars, Anders, Soren...