表(2)-5．母体出産時推定血中ダイオキシン類濃度と児の出生体重との関連(TSUKIMORI et al. Environ Int 2012 $ ^{10} $ )より引用)

Log10 scale (TEQ pg/g lipid)	TEF a	Total b	Female c	Male c
Beta d	95%CI	p value	Beta d	95%CI	p value	Beta d	95%CI	p value
Total level
Total PCDDs TEQ	−161.9	−265.3 to −58.6	0.002	−105.9	−286.9 to 75.2	0.248	−201.9	−334.0 to −69.8	0.003
Total PCDFs TEQ	−105.9	−179.5 to −32.2	0.005	−67.8	−203.6 to 68.0	0.323	−130.0	−220.9 to −39.2	0.005
Total non-ortho PCBs TEQ	−178.4	−318.3 to −38.5	0.013	−141.6	−392.1 to 108.8	0.263	−206.2	−384.3 to −28.1	0.024
Total TEQ	−137.9	−228.9 to −47.0	0.003	−92.3	−257.8 to 73.2	0.270	−168.2	−281.6 to −54.8	0.004
Congener level
2,3,7,8-TCDD	1	−130.2	−225.6 to −34.9	0.008	−76.3	−241.8 to 89.2	0.361	−164.0	−286.6 to −41.4	0.009
1,2,3,7,8-PeCDD	1	−176.4	−290.7 to −62.1	0.003	−117.6	−316.1 to 80.8	0.241	−218.0	−365.0 to −71.0	0.004
1,2,3,4,7,8-HxCDD	0.1	−155.2	−276.1 to −34.2	0.012	−80.8	−292.3 to 130.7	0.449	−203.7	−359.0 to −48.5	0.011
1,2,3,6,7,8-HxCDD	0.1	−189.2	−318.7 to −59.6	0.004	−134.6	−358.7 to 89.5	0.235	−239.3	−408.3 to −70.2	0.006
1,2,3,7,8,9-HxCDD	0.1	−178.8	−285.5 to −52.1	0.005	−129.0	−327.9 to 69.8	0.200	−204.4	−357.1 to −51.7	0.009
1,2,3,4,6,7,8-HpCDD	0.01	−177.8	−296.9 to −58.6	0.004	−91.0	−303.2 to 121.3	0.396	−242.6	−393.0 to −92.1	0.002
OCDD	0.0003	−162.1	−264.6 to −59.7	0.002	−107.8	−284.8 to 69.1	0.228	−204.0	−336.5 to −71.4	0.003
2,3,7,8-TCDF	0.1	NA
1,2,3,7,8-PeCDF	0.03	NA
2,3,4,7,8-PeCDF	0.3	−90.4	−170.3 to −28.5	0.006	−64.1	−194.2 to 66.1	0.330	−122.1	−209.8 to −34.4	0.007
1,2,3,4,7,8-HxCDF	0.1	−91.1	−150.7 to −31.5	0.003	−66.7	−179.7 to 46.3	0.243	−105.6	−178.0 to −33.3	0.005
1,2,3,6,7,8-HxCDF	0.1	−108.7	−178.9 to −38.5	0.003	−71.5	−201.3 to 58.2	0.275	−132.0	−218.1 to −45.9	0.003
1,2,3,7,8,9-HxCDF	0.1	NA
2,3,4,6,7,8-HxCDF	0.1	NA
1,2,3,4,6,7,8-HpCDF	0.01	−114.1	−187.7 to −40.5	0.003	−58.7	−190.5 to 73.0	0.377	−151.0	−242.1 to −59.9	0.001
1,2,3,4,7,8,9-HpCDF	0.01	NA
OCDF	0.003	NA
3,3',4,4'-TCB(#77)	0.0003	NA
3,4,4',5-TCB(#81)	0.0001	NA
3,3',4,4',5-PeCB(#126)	0.1	−177.8	−317.1 to −38.4	0.013	−188.8	−439.6 to 61.9	0.138	−174.5	−351.5 to 2.5	0.053
3,3',4,4',5,5'-HxCD(#169)	0.03	−146.5	−269.1 to −23.9	0.019	−70.1	−290.2 to 150.1	0.528	−198.3	−352.8 to −43.7	0.012

NA, not applicable because many values were under the detection limit.

$ ^{a} $ WHO 2005 toxic equivalent factor values (Van den Berg et al., 2006).

$ ^{b} $ Results were calculated as multiple linear regression models adjusted for gestational age, maternal age at delivery, parity at delivery, smoking status during pregnancy, infant gender, number of births, duration of breast feeding and frequency of seafood consumption.

Results were calculated as multiple linear regression models adjusted for gestational age, maternal age at delivery, parity at delivery, smoking status during pregnancy, number of births, duration of breast feeding and frequency of seafood consumption.

$ ^{d} $ Beta coefficients represent the change in birth weight (g) for a 10-fold increase in the levels of PCDDs/PCDFs and non-ortho PCBs.

つぎに児の性差により母体血中ダイオキシン類濃度の出生体重に及ぼす影響が異なるかどうかについて検討した。男児においてはtotal PCDD、total PCDF、total non-ortho PCBsおよびtotal TEQ濃度は出生体重と有意に負の相関を示すが、女児においてはこれらダイオキシン類濃度と出生体重との間には有意な相関はなかった(表(2)-5、図(2)-2)。母体出産時推定血中ダイオキシン類濃度は男児と女児の間に有意な差はなかった(表(2)-6)。フィンランドにおける正常妊娠167例から採取した母乳中のダイオキシン類濃度と出生体重との関連に関する検討では、男児では母乳中PCDD/PCDF濃度と出生体重は有意に負の相関(相関係数=-0.239、p=0.038)を示すが、女児ではこれらの間に有意な相関はなかった（相関係数=-0.0806、p=0.450） $ ^{19)} $ 。また、わが国における正常妊娠514例を対象とした検討でも、男児では母体血中PCDD/PCDF濃度と出生体重との間には有意に負の相関(p=0.022)を示すが、女児ではこれらの間に有意な相関はなかった（p=0.195） $ ^{2)} $ 。これらの成績から、母体血中ダイオキシン類濃度の増加による出生体重への影響は、男児の方が女児に比べて影響を受けやすいことが示唆された。