Effect of cigarette smoke on fertility parameters in inbred
Balb-C type male and female mice – An experimental in vitro fertilisation mice
model study
H. Hassa1, F. Gürer2, H.M. Tanir1, M. Kaya1, A. Eker Sariboyaci2, N.
Balkose Gunduz2, C. Bal3
1Eskisehir Osmangazi University School of Medicine,
Department of Obstetrics and Gynecology, Eskisehir, Turkey, 2Eskisehir
Osmangazi University School of Medicine, Department of Histology and Embryology,
Eskisehir, Turkey, 3Eskisehir Osmangazi University School of Medicine,
Department of Biostatistics, Eskisehir, Turkey
Objective This study was
designed to elucidate if any, the effect of cigarette smoke on number of
collected oocytes, fertility and cleavage rates, embryo development in an
experimental in vitro fertilisation (IVF) model of inbred Balb-C type mice and,
secondarily to observe if female or male smoke-exposure alone has an impact on
the fertility parameters.
Design and methods All female and male rats (18-25
gr) aged 14-16 weeks were separated and divided into cigarette smoke-exposed
(SE) and non-smoke exposed (NSE) groups. A specially designed cage with
cigarette smoking machine was constructed. All SE (20 cigarette/day) groups were
put in the cage for 10 weeks. SE and NSE female and male mice were cross-mated
with each other as to give four different subgroups (n:10) of mice population.
Group I comprised NSE male and female mice; group II consisted of SE female mice
and NSE male mice; group III had NSE female with SE mice and finally group IV
had SE male and SE female mice population. Fertilisation, cleavage rates and day
3 embryo grading (GI-III) were assessed in four groups. Statistical analysis was
performed by using SPPS 13.0 programme. For comparison of proportions, Z-test
and Fisher’s exact chi-square tests were applied for parametric and
non-parametric data distributions, respectively.
Results With regard to
fertilisation rate, group II (%36) significantly differed from group I (85%,
p=0.002), III(68.7%,p=0.04) but not different from group IV(20.6%, p=0.34). No
statistically significant difference was present among all groups with regard to
cleavage rate (Fisher’s exact ?2 test, p>0.05). Taken embryo development rate
into consideration, Group II (32%) had lower percentage, compared to group group
I (75%;z:3.2, p<0.01) and group III (62.5%; z:4.8, p<0.001) but not different from IV (17.2%; z:0.8, p=0.42). Number of grade I Day 3 embryos did not differ among four groups, respectively (Fisher's exact ?2 test, p>0.05).
Conclusions Fertilisation and cleavage rates were affected mainly by cigarette
smoke-exposed female mice population. When female mice was controlled for smoke
exposure, SE male rats did affect, to a lesser extent, those above-mentioned
fertility parameters with no statistical significance.