Dear member, Thanks for writing. Thick viscosity semen will cause difficulty in the movement of sperms.sperms have to swim from the vaginal canal to the fallopian tube where the egg is present if pregnancy has to occur. Thus sperms cannot reach the fallopian tube in good numbers when trapped in thick semen. The yellow color may be due to infection. Please do a detailed urine ans semen culture . Visit a urologist for same. After antibiotics doxycycline 100 mg twice a day for 2 weeks the infection will subside. Then a multivitamin and antioxidant like Fertisure M has to be consumed along with tab clomiphene 25 mg for 3 cycles. Usually you will be able to conceive spontaneously. Please write back with investigation to Dr bhagyashree Thanks Dr Bhagyashree The