Long-term effects of polychlorinated biphenyls and dioxins on pregnancy outcomes in women affected by the Yusho incident.
BACKGROUND
Maternal exposure to polychlorinated biphenyls (PCBs) is associated with increased proportions of spontaneous abortion and stillbirth in animal studies. In Japan in 1968, accidental human exposure to rice oil contaminated with PCBs and other dioxin-related compounds, such as polychlorinated dibenzofurans (PCDFs), led to the development of what was later referred to as Yusho oil disease.


OBJECTIVE
The aim of this study was to investigate the association of maternal PCB and dioxin exposure with adverse pregnancy outcomes in Yusho women.


METHODS
In 2004, we interviewed 214 Yusho women (512 pregnancies) about their pregnancy outcomes over the past 36 years. Pregnancy outcomes included induced abortion, spontaneous abortion, preterm delivery, and pregnancy loss.


RESULTS
In pregnancy years 1968-1977 (within the first 10 years after exposure), the proportions of induced abortion [odds ratio adjusted for age at delivery (ORadj) = 5.93; 95% confidence interval (CI), 2.21-15.91; two-tailed p < 0.001) and preterm delivery (ORadj = 5.70; 95% CI, 1.17-27.79; p = 0.03) were significantly increased compared with the proportions in pregnancy years 1958-1967 (10 years before the incident). Spontaneous abortion (ORadj = 2.09; 95% CI, 0.84-5.18), and pregnancy loss (ORadj = 2.11; 95% CI, 0.92-4.87) were more frequent (OR = 2.18; 95% CI, 1.02-4.66), but these were not significant (p = 0.11 and p = 0.08, respectively) in pregnancy years 1968-1977. We found no significant increases in the proportions of these adverse pregnancy outcomes in pregnancies occurring during 1978-1987 or 1988-2003 compared with those in pregnancies before 1968.


CONCLUSIONS
High levels of PCB/PCDF exposure had some adverse effects on pregnancy outcome in Yusho women.
Tsukimori
Kiyomi
K
Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. tsuki@med.kyushu-u.ac.jp
Tokunaga
Shoji
S
Shibata
Satoko
S
Uchi
Hiroshi
H
Nakayama
Daisuke
D
Ishimaru
Tadayuki
T
Nakano
Hitoo
H
Wake
Norio
N
Yoshimura
Takesumi
T
Furue
Masutaka
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004147:Dioxins / Q000032:analysis / Q000633:toxicity*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D007564:Japan; D018811:Maternal Exposure; D008875:Middle Aged; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D013997:Time Factors
D004147:Dioxins; D011078:Polychlorinated Biphenyls