fertilization


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fertilization

 [fer″tĭ-lĭ-za´shun]
in human reproduction, the process by which the male's sperm unites with the female's oocyte, creating a new life. The sex and other biologic traits of the new individual are determined by the combined genes and chromosomes that exist in the sperm and oocyte. See also conception and reproduction. Called also fecundation and impregnation.

After injection into the vagina, millions of sperm cells (spermatozoa) make use of their whiplike tails to swim through the cervix toward the uterus. Most are destroyed along the way by secretions in the vagina, but some reach the uterus and a few may enter the fallopian tubes. A very small number may survive as long as 48 hours. If during this period only one sperm succeeds in entering a fallopian tube and meeting there an oocyte ready to be fertilized, conception can occur. This event is possible only during a period of about 4 days of the month. After the sperm lodges in the oocyte, the tail disappears, but the head unites with the oocyte to form the zygote.
in vitro fertilization the process by which conception takes place in a laboratory medium; the term literally means fertilization “in glass.” A lay term for the product of in vitro fertilization is “test tube baby.”

The treatment cycle involves the following steps: (1) Induction of ovulation with fertility drugs, such as clomiphene citrate, injectable follicle-stimulating hormone/luteinizing hormone, or both, to produce multiple ovarian follicles. When the largest follicle reaches 20 mm in diameter the patient is given an injection of human chorionic gonadotropin to induce expulsion of the oocyte from the follicle. (2) Laparoscopy and follicular aspiration for the harvesting of oocytes. (3) Maturation of retrieved oocytes and inoculation with the husband's or donor's sperm. (4) Incubation of the resulting embryos until they reach the two- to six-cell stage. (5) Transfer of an embryo via catheter into the patient's uterus; at this point intensive intervention ceases, the pregnancy is considered normal, and no further manipulation is required.
in vivo fertilization union of the sperm and ovum within the reproductive tract of the female; usually taken to mean artificial insemination in which the sperm is artificially introduced into the vagina, cervix, or uterine cavity to overcome the problem of infertility.

fer·til·i·za·tion

(fer'til-i-zā'shŭn),
The process beginning with penetration of the secondary oocyte by the sperm and completed by fusion of the male and female pronuclei.

fertilization

(fûr′tl-ĭ-zā′shən)
n.
1. The act or process of initiating biological reproduction by insemination or pollination.
2. The union of male and female gametes to form a zygote.
3. The act or process of applying a fertilizer.

fer′til·i·za′tion·al adj.

fertilization

Fusion of ovum & spermatozoon Reproduction medicine The penetration of an egg by sperm, resulting in combined genetic material that develops into an embryo

fer·til·i·za·tion

(fĕr'til-ī-zā'shŭn)
The process beginning with penetration of the secondary oocyte by the sperm and completed by fusion of the male and female pronuclei.

fertilization

(fert?il-i-za'shon) [L. fertilis, reproductive]
Enlarge picture
FERTILIZATION
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: illustration

heterologous fertilization

Assisted fertilization of a woman's ova with donor sperm.
See: in vitro fertilization; artificial insemination

homologous fertilization

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.

in vitro fertilization

Abbreviation: IVF
Laboratory-produced conception, used to enable pregnancy in infertile women when sperm access to ova is prevented by structural defects in the fallopian tubes or other factors, or in combination with her partner's sterility. 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.
See: embryo transfer; GIFT; ZIFTillustration

fertilization

The union of the spermatozoon with the egg (ovum) so that the full complement of chromosomes is made up and the process of cell division, to form a new individual, started.

fertilization

the fusion of male and female GAMETES to give rise to a ZYGOTE which then subsequently develops into a new organism. See ACROSOME for further details of animal fertilization. See EMBRYO SAC for details of the ‘double’ fertilization of flowering plants.

Fertilization

The joining of the sperm and the egg; conception.
Mentioned in: Contraception

fer·til·i·za·tion

(fĕr'til-ī-zā'shŭn)
Process beginning with penetration of secondary oocyte by one or more sperm(s) and completed by fusion of the male and female pronuclei.

Patient discussion about fertilization

Q. i just have my period last november 25 and ended on 28.when is my possible fertile and ovulation period please help me identify my fertile and ovulation period

A. If someone knew it, it'd solve the human race many problems with fertility. The problem is that ovulation (and thus, the period of possible fertility) happens 14 days BEFORE the onset of menses, so you know about it only retrospectively.

However there ways such as serial body temperature measuring, along with kits that measures the level of hormones in the urine in order to estimate the time of the coming ovulation, and help in timing intercourse.

You may read more about it here (www.mayoclinic.com/health/ovulation-signs/AN01521 ) but anyway, consulting a doctor (e.g. gynecologist) may be wise.

More discussions about fertilization
References in periodicals archive ?
For product type segment, this report listed main product type of In Vitro Fertilization market
Significances in ANOVA of spring wheat response to nitrogen fertilization [A] and bioregulators application [B] in the years of the study.
However, the research team failed to indentify the correlation between air pollutants and a lower pregnancy rate _ although it believes they have a similar influence on fertilization as does secondhand smoking.
This gave an unprecedented view of how gametes recognize each other in a species-specific way at the beginning of fertilization.
Pharyngula stage starts after 40th h till 88th h after post fertilization (2-4 dpf) characterized with rudiment pharyngeal arches, which were present, but difcult to differentiate independently at earlier period.
Thus, the aim of this research was to understand the effects of coverage with nitrogen and macro and micronutrients leaf fertilization on yield and physiological quality of upland rice seeds.
The experiment was laid out in a randomized complete block design with four treatments and three replicates consisting of; PK=chemical phosphorus and potassium fertilization with no nitrogen; (2) NK= chemical N and K fertilization with no phosphorus; (3) NP = chemical N and P fertilization with no potassium; (4) NPK= chemical N, P and K fertilization.
In the ADUBARROZ sequence, a series of screens is designed to determine whether the expected response to fertilization will be very high, high, medium or low, according to criteria established by SOSBAI (2014).
At the spacings of 1.00 x 0.50 m and 3.00 x 1.00 x 0.25 m, plants fertilized with NPK and NP showed greater height and higher number of cladodes (p < 0.05), respectively, compared with the treatments without fertilizer and with P application, while at spacings of 1.00 x 0.50 m, for the number of cladodes, and 2.00 x 0.25 m, for the number of cladodes and CAI, the values were higher in plants fertilized with NPK, in comparison to NP; plants fertilized with P and without fertilization showed the lowest values.
Objective: To identify predictors of fertilization rate in patients of unexplained infertility after intracytoplasmic sperm injection (ICSI).
Most studies use sperm motility as a parameter for sperm quality, but, according to Bobe & Labbe (2010), only the success of fertilization allows to prove accurately the quality of sperm and oocyte.