Pregnancy planning, smoking behaviour during pregnancy, and neonatal outcome: UK millennium cohort study

Table 4 Association between change in smoking behaviour during pregnancy (yes/no) and neonatal outcome, in mothers who smoked just before pregnancy

	Mothers who smoked just before pregnancy
	Neonatal outcome in mothers	Neonatal outcome in mothers	Crude¹		Adjusted 1*		Adjusted 2**
	who did not change their	who decreased or quit
	smoking habit during pregnancy	smoking during pregnancy
	n/N (%)	n/N (%)	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)
Low birth weight (<2.5 kg)	136/1,183(11.50)	365/4,834(7.55)	0.62	(0.50-0.79)	0.65	(0.50-0.84)	0.66	(0.51-0.85)
Prematurity (< 37 weeks gestation)	109/1,167 (9.34)	376/4,799 (7.83)	0.82	(0.65-1.03)	0.85	(0.67-1.08)	0.85	(0.67-1.09)

¹Baseline group was women who did not change their smoking habit during pregnancy.
*Birth weight adjusted for mother’s age, education, ethnicity, religion and BMI. Prematurity adjusted for mother’s age, relationship status and education.
**Adjusted for the same variables as model 1 plus planning.

ISSN: 1471-2393