Objective To investigate the role of sperm morphology in

in vitro

fertilization (IVF). Methods  Relationship between sperm morphology and other sperm parameters and effects of normal forms on IVF outcomes were retrospectively analyzed from 397 IVF cycles in our department from 2008 to 2009. Three group were divided based on sperm morphology

which defined ≤ 5% normal forms as group A

5% and ≤ 14% as group B

and 14% as group C. The IVF outcomes included the clinical pregnancy

pregnancy failure and no embryo transfer. Results The percentage of sperm normal forms was s

ignificantly correlated with sperm density

motility

percentage of progressive motile sperm (PMS%) (

r

=0.188

0.197 and 0.190

all

P

0 . 01). The normal form rate

density

motility and PMS% were positively correlated with the fertilization rates (

r

= 0.237

0.171

0.155 and 0.187

P

0 . 01). There were significant differences in the fertilization rates among groups A

B and C (

P

0 . 05). The normal form rates of sperms in patients with no embryo transfer were markedly lower than that in patients with clinical pregnancy [(15.53 ± 7.54)%

vs

(20.05 ± 9 . 51)%

P

0 . 05

]

but no differences was found between the clinical pregnancy group and the pregnancy failure group. The age in group A was significantly older than that in groups B and C (41.4 ± 14.1

vs

35.4 ± 6.4 and 34.7 ± 4.6

P

0 . 05 and

P

0 . 01) among patients with secondary sterility. Conclusion  The sperm morphology affects fertilization rates and clinical outcomes in IVF

and may be a better predictive parameter for fertilization in IVF. The sperm normal forms will be decreased with patient age.