Table 4.

Unadjusted and adjusted mean birth weight (grams) among quitters, before and during the Tips campaign: Indiana, Kentucky, Ohio, 2009–2013

Exposure	Women who quit smoking by the third trimester
	Unadjusted		Adjusted*
	Mean birth weight	Mean difference	Mean birth weight	Mean difference
Unexposed (precampaign) (n=65 658)†	3309	−5.2	3228	−2.0
Exposed (during campaign) (n=20 092)‡	3314	95%  CI − 14.1 to 3.8	3230	95%  CI − 9.0 to 5.0

*Adjusted for maternal age; race; education; marital status; parity; Woman, Infants and Children enrolment; prepregnancy body mass index; insurance status; state; and gestational age.

†Births to women who smoked in the 3 months before pregnancy and delivered prior to the Tips 2012 campaign (1 January 2009 to 18 March 2012).

‡Births to women who smoked in the 3 months before pregnancy and for whom there was temporal overlap between the Tips 2012 campaign and the period including her pregnancy (first and second trimesters) and the preceding 3 months.