Table 2.

Weights (g) of in utero opioid exposed neonatal guinea pigs compared to vehicle

Age	Vehicle	Methadone	Morphine
Birth	102 ± 4	81 ± 4**	82 ± 3**
3 days	102 ± 4	82 ± 5**	84 ± 3**
7 days	132 ± 6	116 ± 8*	112 ± 5**
14 days	189 ± 12	147 ± 10*^^	178 ± 9

^*p<0.05 vs. vehicle

^**p<0.01 vs. vehicle

^***p<0.001 vs. vehicle

^{^^}p<0.01 vs. morphine, all values reported as mean ± S.E. of all pups in each treatment group, n (per treatment): Birth and day 3, 18 pups; day 7, 12 pups; day 14, 6 pups.