Re: Meconeum stain
From: James S Smeltzer MD (gaperina@mindspring.com)
Mon Jul 16 00:25:43 2001
Hi Belal,
I have never found a way.
Vernix, meconium and many other suspended substances are in AF.
Amnioscopy can tell. Look at membranes and AF thru the cervix. If it
appears green, it is meconium. Otherwise, turn on the green filter and if
the particles look green it might be meconium. Look in the fetal rectum,
and if you are fairly sure it is empty after 34 weeks, it is probably
meconium. Else look for the spectral US absorbance frequency of meconium vs
the other substances in AF and if there is more than average attenuation in
that freq vs others, bet on mec absorbtion vs the normal stuff.
Else do an amnio and look at fluid color or biliverdin content.
If layering is seen, bilirubin floats. If
At 01:35 PM 6/2/2001 -0500, you wrote:
>At Mon, 28 May 2001, Belal Hossain wrote:
>>
>>Is it possible to diagnose meconeum stained liq by usg? If yes,what could
be the finding over a b/w monitor?
>>yours etc,
>>Dr Belal Hossain,MD
>>Kolaghat.India
>>
>
>Dear Dr. Hossain,
>Unfortunately, ultrasound has not been successful in identifying
>meconium in amniotic fluid. See below.
>
>Regards,
>Paula Woletz
>
>1: J Clin Ultrasound 1998 May;26(4):191-3
>
>Clinical significance of echogenic amniotic fluid.
>
>Petrikovsky B, Schneider EP, Gross B.
>
>Division of Maternal Fetal Medicine, North Shore University Hospital,
>New York
>University School of Medicine, Manhasset 11030, USA.
>
>PURPOSE: This study aimed to determine the clinical significance of
>echogenic
>amniotic fluid. METHODS: We prospectively studied 19 twin pregnancies
>in which
>the amniotic fluid in 1 sac was anechoic and that in the other sac was
>echogenic. Morphologic characteristics of amniotic fluid were assessed
>from
>samples taken at amniocentesis or upon delivery within 48 hours after
>sonographic examination. RESULTS: In twins with echogenic amniotic
>fluid,
>assessment revealed clear fluid in 6 cases (32%), vernix caseosa in 12
>(63%),
>and meconium in 1 (5%). In co-twins with anechoic amniotic fluid,
>assessment
>revealed clear fluid in 9 cases (47%), vernix caseosa in 6 (32%), and
>meconium
>in 4 (21%). CONCLUSIONS: Echogenic amniotic fluid on prenatal
>sonography is not
>predictive of meconium.
>
>PMID: 9572381 [PubMed - indexed for MEDLINE]
>
>2: J Ultrasound Med 1994 Feb;13(2):95-7
>
>Very echogenic amniotic fluid: ultrasonography-amniocentesis
>correlation.
>
>Brown DL, Polger M, Clark PK, Bromley BS, Doubilet PM.
>
>Department of Radiology, Brigham and Women's Hospital, Harvard Medical
>School,
>Boston, MA 02115.
>
>Very echogenic amniotic fluid has been variably attributed to meconium,
>blood,
>or vernix caseosa. However, most previous reports have been case
>reports, and
>most cases have not had proof by amniocentesis. In a larger series of
>patients
>with proof by amniocentesis, we sought to determine the relative
>frequency of
>these substances as causes of very echogenic amniotic fluid. We
>retrospectively
>identified obstetric sonograms in which the amniotic fluid was
>homogeneously
>filled with innumerable echogenic particles. The cause of the increased
>echogenicity was determined by fluid appearance at amniocentesis. Of 86
>cases
>identified, immediate proof by amniocentesis was available in 19
>patients for
>whom the gestational age ranged from 32.8 to 39.4 weeks. Vernix was
>present in
>18 (95%) patients and meconium in one (5%) patient. Very echogenic
>amniotic
>fluid in the third trimester is most often due to vernix and
>infrequently due to
>meconium. This sonographic finding is not a reliable indicator of
>meconium or
>blood in amniotic fluid and should not typically alter antenatal
>management.
>
>PMID: 7932968 [PubMed - indexed for MEDLINE]
>
>3: Obstet Gynecol 1991 Nov;78(5 Pt 1):819-22
>
>Sonographically homogeneous echogenic amniotic fluid in detecting
>meconium-stained amniotic fluid.
>
>Sherer DM, Abramowicz JS, Smith SA, Woods JR Jr.
>
>Department of Obstetrics and Gynecology, Strong Memorial Hospital,
>Rochester,
>New York.
>
>A prospective study was performed to examine the hypothesis that
>sonographically
>homogeneous echogenic amniotic fluid (AF) may provide a marker for the
>presence
>of meconium-stained AF. Twenty term gestations in which homogeneous
>echogenic AF
>was demonstrated sonographically were compared with 40 cases with
>sonographically clear AF. Two cases in the study group had
>meconium-stained AF
>at delivery. All of the controls had clear fluid by amniocentesis
>(performed for
>lung maturation studies) immediately after the sonographic examination.
>Thus,
>homogeneous echogenic AF had a sensitivity of 100%, a specificity of
>69%, a
>positive predictive value of 10%, and a negative predictive value of
>100% in
>detecting meconium. We conclude that homogeneous echogenic AF does not
>necessarily detect meconium-stained AF.
>
>PMID: 1923205 [PubMed - indexed for MEDLINE]
>
>4: J Perinat Med 1989;17(5):333-5
>
>Sonographic detection of echogenic amniotic fluid and its clinical
>significance.
>
>Sepulveda WH, Quiroz VH.
>
>Department of Obstetrics and Gynecology, Guillermo Grant Benavente
>Hospital,
>Concepcion, Chile.
>
>It has been suggested that meconium-stained amniotic fluid can be
>detected in
>the antepartum period by means of ultrasound, based on the following
>findings:
>(1) a diffuse echogenic pattern throughout the amniotic cavity, (2) a
>clear
>contrast between the amniotic fluid and the umbilical cord, and (3)
>layering in
>the more dependent areas. Reported is a case in which a similar picture
>was
>obtained in a third trimester, high-risk pregnancy, but representing
>vernix
>instead of meconium. We are aware of six cases, including ours, of
>sonographic
>detection of echogenic amniotic fluid. The review of these cases
>indicates that
>the findings refer more often to a considerable amount of vernix rather
>than
>meconium, and it is not necessarily associated with postmaturity. If
>echogenic
>amniotic fluid is identified in an obstetrical ultrasound, we recommend:
>(1)
>rule-out meconium by amniocentesis or amnioscopy, or (2) study fetal
>well-being
>by means of nonstress test and/or biophysical profile. Thus, a false
>positive
>diagnosis of fetal distress in these cases could be easily avoided.
>
>PMID: 2696778 [PubMed - indexed for MEDLINE]
>
