Solvents: pregnancy outcome and
fertility
Marja-Liisa Lindbohm
Finnish Institute of Occupational
Health
Organic solvents

one of the most important occupational
reproductive hazards:
 widely used in various fields of industry
 volatile liquids
 absorbed via inhalation and through the
skin
 most solvents traverse the placenta
Reproductive effects of solvents



teratogenic, embryotoxic and behavioral effects in
animal tests on mammals
in several human studies exposure related to
 adverse pregnancy outcome and reduced fertility
in some studies exposure related also to
 menstrual disorders and reduced hormone levels
 reduced semen quality
 pregnancy-induced hypertension
 neurobehavioral performance
 childhood cancer
Industries / individual solvents related to
reduced fertility or adverse pregnancy
outcome




Dry cleaning / tetrachloroethylene
Shoe and leather industry / aliphatic hydrocarbons,
toluene, hexane
Semiconductor industry / ethylene glycol ethers
Laboratory work / toluene, xylene, chloroform
Maternal exposure to tetrachloroethylene
in dry cleaning and spontaneous abortion
Study
Odds ratio
95 % CI
Kyyrönen et al. 1989
3.4
1.0 - 11.2
Ahlborg et al. 1990
1.1
0.5 - 2.2
Olsen et al. 1990
2.9
1.0 - 8.4
Doyle et al. 1997
1.6
1.0 - 2.7
Spontaneous abortion, subfertility and maternal
exposure to ethylene glycol ethers in
semiconductor industry (Correa et al. 1996)
Spontaneous
abortion
Subfertility
Exposure level
RR/OR
95% CI
low
1.0
0.6 - 1.7
medium
1.4
0.8 - 2.6
high
2.8
1.4 - 5.6
low
1.5
0.7 - 3.1
medium
1.8
0.8 - 4.3
high
4.6
1.6 - 13.3
Results of studies among women working in
the shoe and leather industry

indications of an increased risk of perinatal death,
stillbirth, and oral clefts in children of shoe and
leather workers (likely exposed to solvents)

increased risk of spontaneous abortion and
decreased fertility among shoe workers exposed to
solvents (aliphatic hydrocarbons, toluene, hexane,
acetone)
Cumulative percentage of pregnancies by
maternal exposure to solvents (Sallmén et al 1995)
100
pregnant, %
80
60
Unexposed
Low
High
40
20
0
1
2
3-
5-
Menstrual cycle
7-
13-24
Maternal exposure to solvents and birth
defects

McMartin et al. 1998:
 meta-analysis of five studies (n=7036)
 summary OR=1.64 (95% CI 1.16 - 2.30)

Solvent exposure linked with
 central nervous system defects, oral clefts,
gastroschisis, ventricular septal defects, urinary
tract defects
Conclusions: Effects of solvent exposure
on the reproductive health of women



High exposure to solvents increases the risk of
spontaneous abortion and decreases fertility
The findings on birth defects less conclusive, but
suggesting adverse effects
Particular solvents associated with adverse
outcome: ethylene glycol ethers, tetrachloroethylene, toluene
Exposure to solvents and semen quality
or hormone levels






2-bromopropane: reduced sperm count
Ethylene glycol ethers: reduced sperm count
Styrene and acetone: sperm anomalies
Toluene: decrease of gonadotropin hormone levels
Trichloroethylene: hyperzoospermia
Solvents: low active sperm count and decreased
implantation rate
Cumulative percentage of pregnancies by
paternal exposure to solvents (Sallmén et al. 1998)
100
pregnant, %
80
60
Unexposed
Low
High
40
20
0
1
2
3-
5-
Menstrual cycle
7-
13-24
Conclusions: Effects of solvent exposure
on the reproductive health of men




Ethylene glycol ethers harmful for male
reproductive system
Carbon disulfide related to decreased libido and
potency in men
No clear association between solvent exposure and
decreased fertility
Evidence on the effects of paternal exposure on
pregnancy outcome inconclusive, although
suggestive associations noted
Hazard assessment



Exposure may be high for example in spray
painting, shoe making, degreasing, printing and
dry cleaning
Assessment of solvent exposure with industrial
hygienic measurements or biological monitoring
In some countries the guidelines recommend that
solvent exposure should not exceed 10% of the
threshold limit value during pregnancy
References on solvent exposure and
reproductive health



McMartin KI, Chu M, Kopecky E, Einarson TR, Koren
G. Pregnancy outcome following maternal organic
solvent exposure: a meta-analysis of epidemiologic
studies. Am J Ind Med 1998;34:288-292.
Tas S, Lauwerys R, Lison D. Occupational hazards
for the male reproductive system. Crit Rev Toxicol
1996;26:261-307.
Lindbohm M-L. Effects of parental exposure to
solvents on pregnancy outcome. J Occup Environ
Med 1995;37:908-914.