fertilization
(fĕrt‵ĭl-ĭ-zā'shŏn 
)
[L. fertilis, reproductive]
The process that begins with the penetration of the secondary oocyte by the spermatozoon and is completed with the fusion of the male and female pronuclei. This usually takes place in the fallopian tube. Viable spermatozoa have been found in the tube 48 hr after the last coitus. After the ovum is fertilized and the diploid chromosome number is restored in the zygote, cell division begins. The blastocyst then enters the uterus, where it may implant for continued nurture and development.
SEE: illus.
heterologous f.Assisted fertilization of a woman's ova with donor sperm.
SEE: in vitro fertilization ; artificial insemination.
homologous f.Artificial fertilization of a woman's ovum by her husband 's sperm. The ovum and sperm are united while both are outside the body and then are placed in the uterus during the optimum time for fertilization.
ABBR: IVF
Laboratory-produced conception. It may used to help families without children to conceive. After drug-induced follicle maturation, a sample of ova and follicular fluid is removed surgically and mixed with a specimen of the partner's sperm for incubation. The resulting zygote is introduced into the woman's uterus for implantation.