certain medication have to be taken by all pregnant women. iron has to be taken , starting from 16weeks onwards along with calcium. folic acid
and a multivitamin
are all that are required in the first trimester( ie first 13 weeks). women usually are not able to eat to well in the initial 3 months because of nausea and vomiting
. the heamoglibin might come down a little. but iron taclets are started only by 16 weeks.