Amniotic fluid
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2008-07-06T01:25:01Z
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'''Amniotic fluid''' is the nourishing and protecting liquid contained by the [[amnion]] of a pregnant woman.
The amnion grows and begins to fill, mainly with water, around two weeks after [[fertilization]]. After a further 10 weeks the liquid contains [[protein]]s, [[carbohydrate]]s, [[lipid]]s and [[phospholipid]]s, [[urea]] and [[electrolyte]]s, all which aid in the growth of the fetus. In the late stages of gestation much of the amniotic fluid consists of fetal [[urine]].
The amniotic fluid increases in volume as the fetus grows. The amount of amniotic fluid is greatest at about 34 weeks after conception or 34 weeks ga (gestational age). At 34 weeks ga, the amount of amniotic fluid is about 800 ml. This amount reduces to about 600 ml at 40 weeks ga when the baby is born.
Amniotic fluid is continually being swallowed and "inhaled" and replaced through being "exhaled", as well as being urinated by the baby. It is essential that the amniotic fluid be breathed into the lungs by the fetus in order for the lungs to develop normally. Swallowed aminotic fluid contributes to the formation of [[meconium]].
Analysis of amniotic fluid, drawn out of the mother's abdomen in an amniocentesis procedure, can reveal many aspects of the baby's genetic health. This is because the fluid also contains fetal cells which can be examined for genetic defects. Recent research by researchers led by [[Anthony Atala]] of [[Wake Forest University]] and a team from [[Harvard University]] has found that amniotic fluid is also a plentyful source of non-embryonic [[stem cells]].<ref>{{cite web |url=http://www.nature.com/nbt/journal/v25/n1/abs/nbt1274.html |title=Isolation of amniotic stem cell lines with potential for therapy : Abstract : Nature Biotechnology |accessdate=2007-10-13 |format= |work=}}</ref> These cells have demonstrated the ability to differentiate into a number of different cell-types, including brain, liver and bone.
Amniotic fluid also protects the developing baby by cushioning against blows to the mother's abdomen, allows for easier fetal movement, promotes muscular/skeletal development, and helps protect the fetus from heat loss.
The forewaters are released when the amnion [[Rupture of membranes|ruptures]], commonly known as when a woman's "water breaks". When this occurs during [[Childbirth|labour]] at [[Gestation|term]], it is known as "spontaneous rupture of membranes" ('''SROM'''). If the rupture precedes labour at term, however, it is referred to as "premature rupture of membranes" ('''PROM'''). The majority of the hindwaters remain inside the womb until the baby is born.<ref>[http://www.babyworld.co.uk/faq/individualfaq.asp?Section=Pregnancy&SubSection=Your+body&query=&opt=&page=&question=1711 Forewaters and hindwaters in Q&A section at babyworld.co.uk]</ref>
==Complications related to amniotic fluid==
Too little amniotic fluid ([[oligohydramnios]]) or too much ([[polyhydramnios]] or hydramnios) can be a cause or an indicator of problems for the mother and baby. In both cases the majority of pregnancies proceed normally and the baby is born healthy but this isn't always the case. Babies with too little amniotic fluid can develop contractures of the limbs, clubbing of the feet and hands, and also develop a life threatening condition called [[hypoplastic lungs]]. If a baby is born with hypoplastic lungs, which are small underdeveloped lungs, this condition is potentially fatal and the baby can die shortly after birth.
On every prenatal visit, the obstetrician/gynaecologist should measure the patient's [[fundal height]] with a tape measure. It is important that the fundal height be measured and properly recorded to insure proper fetal growth and the increasing development of amniotic fluid. The obstetrician/gynaecologist should also routinely [[Medical ultrasonography|ultrasound]] the patient—this procedure will also give an indication of proper fetal growth and amniotic fluid development. Oligohydramnios can be caused by infection, kidney dysfunction or malformation (since much of the late amniotic fluid volume is urine), procedures such as [[chorionic villus sampling]] (CVS), and preterm premature rupture of membranes (PPROM).
Oligohydramnios can sometimes be treated with [[bed rest]], oral and intravenous [[Rehydration|hydration]], [[antibiotic]]s, [[steroid]]s, and amnioinfusion.
Polyhydramnios is a predisposing risk factor for [[cord prolapse]] and is sometimes a side effect of a [[macrosomia|macrosomic pregnancy]]. Hydramnios is associated with [[esophageal atresia]]. Amniotic fluid is primarily produced by the mother until 16 weeks of gestation.
Preterm premature rupture of membranes (PPROM) is a condition where the amniotic sac leaks fluid before 38 weeks of gestation. This can be caused by a bacterial infection or by a defect in the structure of the amniotic sac, uterus, or cervix. In some cases, the leak can spontaneously heal, but in most cases of PPROM, labor begins within 48 hours of membrane rupture. When this occurs, it is necessary that the mother receive treatment to avoid possible infection in the newborn.
COLOR OF AMNIOTIC FLUID WITH CONTRAINDICATIONS
GREEN - neco state
YELLOW - hemolitic deisease
BROWN - infection
==See also==
* [[Amniotic sac]]
==References==
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[[de:Fruchtwasser]]
[[es:Líquido amniótico]]
[[ja:羊水]]
[[it:Liquido amniotico]]
[[hr:Plodna voda]]
[[nl:Vruchtwater]]
[[pl:Wody płodowe]]
[[pt:Líquido amniótico]]
[[ru:Амниотическая жидкость]]
{{Pregnancy}}
[[Category:Body fluids]]
[[Category:Developmental biology]]
[[Category:Embryology]]
[[Category:Obstetrics]]
[[Category:Pregnancy]]