@Shalgo yea the same reason was given to me by my MIL...that it is a celebration of a girl turning into a woman and taking up motherhood. and yea she said when it was her godh bharai, she had get ready and also cook for the guests as well😲 but for my godh bharai times have changed so they had ordered food from the caterers!I am a Marwari and yes "Godh Bharai" is done only in first pregnancy...I guess the reason being that it is a celebration that the woman is entering into motherhood. for second pregnancy, she is already a mother and hence the Godh (lap) is not empty and hence no special celebrations reqd...My guess...is godh braai or not a barometer to judge a child's importance (like many posts seem to suggest)
Second reason I could fathom is in our old generations (I mean our grandmom's generation) having 10-12 kids was also common...so imagine having a godh bharai function every second year and managing/organizing that with ur army of kids...and at times even after 1-2 of ur elder kids had been married...I mean so logical to say...ek baar bahut hai...:)