Saturday, January 14, 2017
Amniotic Fluid (AF)
A
Amniotic fluid volume appears to be
determined by a balance between the inflows from fetal urine, and outflows of fetal swallowing and
Some causes of polyhydramnios (too much amniotic fluid) [5]
- Idiopathic (unknown) ~ most cases
- Gastrointestinal abnormalities
- Esophageal atresia
- Intestinal obstruction
- Anencephaly
- Chromosomal abnormalities
- Nonimmune hydrops
- Skeletal dysplasias
- Diabetes
- Twin- to -twin transfusion
- Ruptured membranes
- Congenital abnormalities
- Bilateral renal agenesis or cystic dyplasia
- Obstruction of the urinary tract
- Meckel-Gruber syndrome
- VACTERL (vertebral, anal, cardiac, tracheo-esophageal, renal, limb) association
- Sirenomelia
- Sacral agenesis
- Growth restriction (placental insufficiency)
- Postterm pregnancy
- Drugs
- Angiotensin-converting enzyme inhibitors
- Prostaglandin synthase inhibitors
- Twin- to -twin transfusion
- TRAP (twin reverse arterial perfusion sequence)
- Fetal demise
- Idiopathic
Ultrasound may be used to obtain a qualitative measure of the amount of amniotic fluid present. One ultrasound method of assessing the AF is to measure the depth of the largest visible pocket of fluid surrounding the fetus. The normal range for the deepest vertical pocket (or maximum vertical pocket) is 2 cm to 8 cm in singleton gestations [8-10].
Depth of largest visible pocket |
Qualitative Description |
< 1 cm | severe oligohydramnios |
> 1 and < 2 cm | mild oligohydramnios |
> 2 and < 8 cm | normal |
> 8 and < 12 cm | polyhydramnios |
>12 cm and < 16 | moderate polyhydramnios |
> 16 cm | severe polyhydramnios |
A
nother method for assessing the AF, called the Amniotic Fluid Index (AFI), uses the sum of the deepest vertical pocket of fluid found in each quadrant of the uterus the normal range for the AFI is 5 to 25 cm [12,13]. Both methods are qualitative measures of the AF and may be a poor reflection of the actual amniotic fluid volume [14].REFERENCES:
1.
Lind T. The biochemistry of amniotic fluid. In: Fairweather DVI, Eskes TKAB,
editors. Amniotic fluid research and clinical application. Amsterdam: Excerpta
Medica; 1973. p. 60-81.
2.
Beall MH, et al.,Regulation of amniotic fluid volume. Placenta. 2007 Aug-Sep;28(8-9):824-32. Epub
2007 Feb 15.PMID:17303237
3. Robertson P, Responses of amniotic fluid volume and its four major flows to
lung liquid diversion and amniotic infusion in the ovine fetus. Reprod Sci. 2009
Jan;16(1):88-93. PMID:19144891
4.Brace RA, Wolf EJ.Normal amniotic fluid volume changes throughout pregnancy.
Am J Obstet Gynecol. 1989 Aug;161(2):382-8. PMID:2764058
5.Damato N, et al. Frequency of fetal anomalies in sonographically detected
polyhydramnios. J Ultrasound Med. 1993 Jan;12(1):11-5. PMID:8455215
6.
Peipert JF, Donnenfeld AE, Oligohydramnios: a review.Obstet Gynecol Surv. 1991
Jun;46(6):325-39. PMID:2067755
7. McCurdy CM Jr, Seeds JW. Oligohydramnios: problems and
treatment. Semin Perinatol. 1993 Jun;17(3):183-96.
PMID:7690990
8. Chamberlain PF,Ultrasound evaluation of amniotic
fluid volume. I. The relationship of marginal and decreased amniotic fluid
volumes to perinatal outcome. Am J Obstet Gynecol. 1984 Oct 1;150(3):245-9.
PMID: 6385713
9.Chamberlain PF, Ultrasound evaluation of amniotic fluid volume. II. The
relationship of increased amniotic fluid volume to perinatal outcome.
Am J Obstet Gynecol. 1984 Oct 1;150(3):250-4. PMID:6385714
10.Hill LM, et al. Polyhydramnios: ultrasonically detected prevalence and neonatal
outcome.Obstet Gynecol. 1987 Jan;69(1):21-5.
PMID:3540761
11. Magann EF,et al The ultrasound estimation of amniotic fluid volume in
diamniotic twin pregnancies and prediction of peripartum outcomes. Am J Obstet
Gynecol. 2007;196(6):570. PMID:17547899
12
13. Phelan JP, Smith CV, Broussard P, Small M. Amniotic fluid volume assessment
with the four-quadrant technique at 36-42 weeks' gestation. J Reprod Med. 1987
Jul;32(7):540-2.PMID: 3305930
14.
PMID: 9290442
Other Pregnancy Term
<--Pregnancy Term Keywords --> Pregnancy Abdomen,The Belly,Abdominal circumference (AC),Abortion,Abruptio placenta (Placental abruption),Acceleration,Acromelia,Active Labor,Acute Cervical Insufficiency,Afterbirth,Agenesis of the corpus callosum (ACC),Akinesia,Alloimmunization (Isoimmunization),Alpha-fetoprotein (AFP),Amniocentesis,Amnioinfusion,Amniotic fluid,Amniotic Fluid Index (AFI),Amniotic fluid ‘sludge’,Amniotic sac,Amniotic sheet,Amniotomy (artificial rupture of membranes , AROM),pregnancy terms,elifexpert,Anemia,Anencephaly,Anesthesia,Angle of insonation,Anomaly,Antenatal,Antenatal corticosteroids , ACS,Antepartum,Anterior,Antibody (Immunoglobulin),Anticardiolipin antibodies (ACA, aCL Antibody) *,Anti-c antibody (little c antibody) *,Anti-D antibody (Rh sensitization, Rh disease)*,Anti-Duffy antibody (anti-Fya antibody),Anti-Kell antibody,Anti-Kidd antibody (anti-Jka or anti-Jkb),Anti-Lewis antibody,Anti-S antibody,Apgar Score,First Trimester,Second Trimester,Third Trimester
No comments: