gabbhaparihaara

[James McDermott]

Can anyone provide assistance with the Pali term "gabbhaparihaara" 
(lit. "he protection of the embryo")? PED defines it as "a ceremony 
performed when a woman became pregnant." Other translators, sticking 
more closely to the literal meaning, use it in a more general sense 
to refer to what we today might call pre-natal care. PED further 
equates the term with "gabbhapariharana", which at Vism 500 in fact 
seems to me closer in meaning to "gestation". My question is whether 
there is in fact a formal gabbhaparihaara ceremony? If so, what is 
the Hindu/Sanskrit equivalent? Any additional references to such a 
ritual would be appreciated. [Note: I don't have access to 
Trenckner's Critical Pali Dictionary.]