Table 2.

Pairwise comparisons of nicotine metabolism ratio (NMR) at 12 weeks postpartum with each time‐point antenatally and postpartum

Comparison to 12 weeks postpartum	Percentage difference	95% confidence intervals	P‐value
8–14 weeks' gestation (46 paired samples)	+15%	+1% to +26%	0.034
18–22 weeks' gestation (37 paired samples)	+26%	+12% to +38%	0.001*
32–36 weeks' gestation (31 paired samples)	+23%	+9% to +35%	0.003*
4 weeks postpartum (35 paired samples)	+9%	–12% to +26%	0.405

^*   P values < 0.125 are significant.