the need for contraceptives after childbirth

Good morning and Shabat shalom

I´m sephardic jew from Caracas venezuela.

My name is Isaac Amran. I have a medical question, and my Rab. David Perets Shlita, gave to me your email.

The question is the following:

My wife gave birth in Miami USA in january 14th, 2008 (ve shaa tova a little girl, first one) exactly two month ago. The doctor (Mauricio Bitran), is renombred in the jew community of Miami because he is the gynecologist prefered for the haredim jews for many reason. The principal question is that he say (the delivery was natural, no complications) that she have to take contraceptive pill for a YEAR, saying that the medical Halacha and doctors organization, in general recommended take the pill even in normal delivery. By the way, my wife is very healthy, no pain from the delivery.

I want your opinion if that is the right position in halacha terms because Rab. Perets said No pill, isn´t necessary.

Thank you very much and I hope that you can help me a lot.

Shabat Shalom