Fetal fibronectin
Encyclopedia
Fetal fibronectin is a fibronectin
protein
produced by fetal
cells
. It is found at the interface of the chorion
and the decidua
(between the fetal sac and the uterine lining).
It can be thought of as an adhesive or "biological glue" that binds the fetal sac to the uterine lining.
if a preterm delivery is likely to occur and can be measured in a diagnostic test.
When the fFN test is positive, it is an inconclusive result. A positive result can indicate that a woman will go into preterm labor soon, but she may not go into labor for weeks. When the fFN test is negative, the result is a better predictor. A negative result means that there is little possibility of preterm labour within the next 7 to 10 days, and the test can be repeated weekly for women who remain at high risk. A negative fetal fibronectin test gives a more than 95% likelihood of remaining undelivered for the next 2 weeks. A systematic review
of the medical literature
found that fetal fibronectin is a good predictor of spontaneous preterm birth before cervical dilation
. The test may be run on patients between 22 and 35 weeks gestation.
The test is easily performed and is usually painless. A specimen is collected from the patient using a vaginal swab. The swab is placed in a transport tube and sent to a laboratory for testing. Most labs can easily produce a result in less than one hour.
A false positive fetal fibronectin result can occur if the test is performed after digital examination of the cervix or after having had intercourse. It is important that the swab be taken before a digital vaginal exam is performed.
Fibronectin
Fibronectin is a high-molecular weight glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins. In addition to integrins, fibronectin also binds extracellular matrix components such as collagen, fibrin and heparan sulfate proteoglycans...
protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
produced by fetal
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
. It is found at the interface of the chorion
Chorion
The chorion is one of the membranes that exist during pregnancy between the developing fetus and mother. It is formed by extraembryonic mesoderm and the two layers of trophoblast and surrounds the embryo and other membranes...
and the decidua
Decidua
Decidua is the term for the uterine lining during a pregnancy, which forms the maternal part of the placenta. It is formed under the influence of progesterone and forms highly-characteristic cells.-Etymology:...
(between the fetal sac and the uterine lining).
It can be thought of as an adhesive or "biological glue" that binds the fetal sac to the uterine lining.
Diagnostic test
Fetal fibronectin "leaks" into the vaginaVagina
The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
if a preterm delivery is likely to occur and can be measured in a diagnostic test.
When the fFN test is positive, it is an inconclusive result. A positive result can indicate that a woman will go into preterm labor soon, but she may not go into labor for weeks. When the fFN test is negative, the result is a better predictor. A negative result means that there is little possibility of preterm labour within the next 7 to 10 days, and the test can be repeated weekly for women who remain at high risk. A negative fetal fibronectin test gives a more than 95% likelihood of remaining undelivered for the next 2 weeks. A systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
of the medical literature
Medical literature
Medical literature refers to articles in journals and texts in books devoted to the field of medicine.Contemporary and historic views regarding diagnosis, prognosis and treatment of medical conditions have been documented for thousands of years. The Edwin Smith papyrus is the first known medical...
found that fetal fibronectin is a good predictor of spontaneous preterm birth before cervical dilation
Cervical dilation
Cervical dilation is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery...
. The test may be run on patients between 22 and 35 weeks gestation.
The test is easily performed and is usually painless. A specimen is collected from the patient using a vaginal swab. The swab is placed in a transport tube and sent to a laboratory for testing. Most labs can easily produce a result in less than one hour.
A false positive fetal fibronectin result can occur if the test is performed after digital examination of the cervix or after having had intercourse. It is important that the swab be taken before a digital vaginal exam is performed.
External links
- Fetal fibronectin - babycenter.com.
- Fibronectin Test - FibronectinTest.co.uk