Difference between revisions of "2010 Group Project 5"

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From the perspective of infant health,preventions can be divided into 3 types:
 
From the perspective of infant health,preventions can be divided into 3 types:
  
a.Primary prevention - turn preterm birth to at term birth.
+
a.Primary prevention - turning preterm birth to at term birth.
  
 
b.Secondary Prevention - intervening before preterm birth.
 
b.Secondary Prevention - intervening before preterm birth.

Revision as of 16:25, 14 September 2010

Fetal Fibronectin

Introduction

Fetal Fibronectin

The Fetal Fibronectin (fFN) test measures the amount of secretions of fFN from a woman's vagina and cervix. This technique is used to determine the likelihood of a premature birth occurring. Fetal fibronectin is a protein based plasma that acts as a form of glue attaching the amniotic sac to the uterine wall. Fetal fibronectin is commonly present between 22 to 35 weeks of pregnancy. It is released into the upper vagina towards the onset of labour. If the test finds fFN between this period, the woman will have a chance of going into labour[1]. Hence, if there is no fFN found, it is most likely that they woman will not going into pre-term labour. Therefore, this test allows the woman to see if they are at risk or not.

About preterm births

Preterm births refer to labour that occurs early than expected. Preterm labour occurs prior to 37 weeks of gestation, Signs include:[2] - Contractions every 10 minutes or more

- Blood or clear, watery discharge from the vagina

- Low backache

- Heavy pelvic pressure

There are many groups of women who are at risk of preterm labour. They include:

- Women who have had a history of preterm births

- Women who are pregnant with twins or more

- Women who have cervical or uterine abnormalities

- Obese or overweight women[3]

- Women associated with an illness or disease (diabetes, high blood pressure)

- Smokers, alcoholics, drug users, stress and women who lack social support

History of Fetal Fibronectin

Procedure

Test Results

Targeted individuals

The American College of Obstetricians and Gynecologists doesn’t recommend pregnant women who have no symptoms and are not at high risk to be put to test, as the test hasn’t shown the accuracy predicting asymptomic woman.[4]

Only 2 groups of pregnant woman would be recommended to put to test, which are the groups that have contractions or other symptoms of preterm labor in between week 24th and 34th.The other group would be the group that are at high risk for preterm labor, such as women with prior preterm delivery, multifetal gestations, uterine abnormalities and cervical factors , but have no symptoms.[5]

The test should only be used on those pregnant woman who are at high risk and show symptoms of preterm labor to help make a more accurate diagnosis. For example, women who have intact amniotic membranes, a cervix that has not dilated more than 3 cm, only slight vaginal bleeding, no cervical cerclage (a cervix that has been sewn shut during pregnancy to keep the baby in the uterus).[6]

Current Research

The fFN(fetal fibronectin) remains relatively very low levels throughout the first 22 weeks of gestation. The following dramatically increase of the concentration that reaches 50 ng/mL or over from 22nd week onwards associates with the increase of the incidence of preterm labor before week 37th of gastation.[7] According to a study carried out in a teaching hospital, the presence of fetal fibronectin in the cervicovaginal secretions of preterm birth symptomatic women indicates a significant risk for subsequent preterm birth while the absence of fetal fibronectin in this group of woman is a very strong indication that subsequent preterm birth is unlikely to occur.[8] The findings are, the preterm birth (before 37 weeks of gestation) rate in the population studied was 19.1%. Fetal fibronectin predicted preterm birth with sensitivity of 63%, specificity of 95.6%, positive predictive value of 77.3%, and negative predictive value of 91.6%. A negative test accurately excluded (97.9%) the chance of subsequent birth during the three weeks interval following sampling.[8]A study with objective to determine the accuracy with which cervico-vaginal fetal fibronectin predicts preterm delivery using systematic quantitative overview of the available literature, concludes that fetal fibronectin test is the most accurate in predicting spontaneous preterm birth within 7 to 10 days after the test of symptomatic woman before advanced cervical dilatation. A total of 26 876 women involved in the study and among asymptomatic women the best summary likelihood ratio for positive results was 4.01, 95% confidence interval 2.93 to 5.49 for predicting birth before 34 weeks gestation, with corresponding summary likelihood ratio for negative results of 0.78. Among symptomatic women the best summary likelihood ratio for positive results was 5.42 for predicting birth within 7-10 days of testing, with corresponding ratio for negative results of 0.25.

Although the test has been commonly used in labour and delivery units to help in the management of preterm labour asymptomatic woman, yet it is not an official screening method to be used of pregnant woman in general, as there is not sufficient evidence to recommend its use as a screening method. Fetal fibronectin test, if combined with clinical findings, has a potentially important role in clinical management of women with symptoms suggestive of preterm labour.[8] Since this review found an association between knowledge of fFN results and a lower incidence of preterm birth before 37 weeks, further research should be encouraged.[9]

Significance

Advantages

Infants that are born preterm are mainly associated with high chances of mortality and getting health and development problems as they grow up. Complications associated include acute respiratory, gastrointestinal, immunologic, central nervous system problems, hearing, and vision defects, longer-term motor, cognitive, visual, hearing, behavioral, social-emotional, health, and growth problems. The birth of a preterm infant can also bring considerable emotional and economic costs to families and have implications for public-sector services, such as health insurance, educational, and other social support systems.[4] Therefore, being able to predict preterm birth would eliminate those problems listed above. The fetal fibronectin test is also a non-invasive test that can be completed quickly.

Disadvantages

There is no side effects in this test, rather the use of fFN test in routine clinical practice allows management and resources to be targeted more appropriately and may limit unnecessary interventions.[10]

Preventions

From the perspective of infant health,preventions can be divided into 3 types:

a.Primary prevention - turning preterm birth to at term birth.

b.Secondary Prevention - intervening before preterm birth.

c.Tertiary Prevention - treatments for premature infants.

However,the progress has mainly been made in the latter two preventions.

The secondary prevention involves the regionalisation of perinatal and neonatal care which ,including matenal transport of impending preterm births and the use of antepartum steroid to speed up the maturation of postnatal lungs.

Tertiary prevention involves developments in neonatal intensive care such as ventilator management and surfactant treatment. It has had a substantial impact on infant mortality yet has less notably affected rates of long-term sequelae.

The secondary and tertiary prevention measures together have lowered gestational age-specific neonatal mortality rates.[11]

External Links

Fetal Fibronectin Test Site

References

  1. 2010 March of Dimes Foundation http://www.marchofdimes.com/professionals/14332_1149.asp
  2. 2010 March of Dimes Foundation http://www.marchofdimes.com/professionals/14332_1149.asp
  3. <pubmed>20647282</pubmed>
  4. 4.0 4.1 Institute of Medicine (US) Committee on Understanding Premature Birth and Assuring Healthy Outcomes; Behrman RE, Butler AS, editors.Washington (DC): National Academies Press (US);2007
  5. <pubmed>7738935</pubmed>
  6. American College of Obstetricians and Gynecologists (ACOG). Assessment of Risk Factors for Preterm Birth. ACOG Practice Bulletin, number 31, October 2001 (reaffirmed 2008).
  7. Akush Ginekol (Sofiia). 2010;49(2):39-42. Bulgarian.
  8. 8.0 8.1 8.2 <pubmed>8688390</pubmed>
  9. <pubmed>18843732</pubmed>
  10. <pubmed>16953860</pubmed>
  11. <pubmed>PMC1508187</pubmed>

Glossary

Amniotic cavity - innermost sac containing amniotic fluid that encloses the embryo.

Uterine wall - the wall of the uterus in the female reproductive system, superior to the cervix.

Symptomatic - involves producing symptoms of a condition.

Asymptomatic - producing or showing no symptoms of a condition.

Gestation - process of the developing embryo, where the fetus is carried in the womb between conception and birth.

Multifetal - involves two or more fetuses in the womb during pregnancy.

Cervical cerclage - stitching a malfunctioning (open) cervix closed during pregnancy to prevent miscarriage.

Antenatal - prenatal, before birth.

Corticosteroids - group of steroid hormones with metabolic functions and inflammatory treatment.

Tocolysis - medications used to supress preterm labour.

2010 ANAT2341 Group Projects

Project 1 - Ultrasound | Project 2 - Chorionic villus sampling | Project 3 - Amniocentesis | Group Project 4 - Percutaneous Umbilical Cord Blood Sampling | Project 5 - Fetal Fibronectin | Project 6 - Maternal serum alpha-fetoprotein | Group Assessment Criteria

Glossary Links

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Cite this page: Hill, M.A. (2021, June 16) Embryology 2010 Group Project 5. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/2010_Group_Project_5

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© Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G