Active and passive maternal smoking during pregnancy and birth outcomes: the Kyushu Okinawa Maternal and Child Health Study

Table 2 Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for birth outcomes and adjusted means of birth weight according to active maternal smoking status during pregnancy in 1565 mother-child pairs

	Low birth weight		Preterm birth		Small-for-gestational-age		Adjusted mean of birth weight, g (95% CI)^a
Maternal smoking	Rate (%)	OR (95% CI)^a	Rate (%)	OR (95% CI)^b	Rate (%)	OR (95% CI)^a
None (n = 1427)	7.4	1.00	3.5	1.00	7.6	1.00	3010.7 (2994.0 − 3027.4)
First trimester only (n = 71)	7.0	0.52 (0.12 − 1.65)	8.5	2.51 (0.90 − 5.98)	4.2	0.53 (0.13 − 1.49)	3027.9 (2951.4 − 3104.3)
Second and/or third trimesters but not throughout (n = 28)	21.4	2.75 (0.71 − 8.89)	10.7	3.14 (0.71 − 9.80)	14.3	1.93 (0.55 − 5.27)	2958.3 (2837.9 − 3078.7)
Throughout (n = 39)	10.3	2.17 (0.48 − 7.14)	7.7	2.06 (0.47 − 6.34)	18.0	2.87 (1.11 − 6.56)	2841.1 (2738.4 − 2943.8)
P for trend		0.19		0.048		0.04	0.005

^a Adjustment for maternal age; region of residence; number of children; family structure; maternal education; maternal employment; alcohol consumption during the preceding month; body mass index; gestational age; and baby’s gender.
^b Adjustment for maternal age; region of residence; number of children; family structure; maternal education; maternal employment; alcohol consumption during the preceding month; body mass index; and baby’s gender.

ISSN: 1471-2393