ABNORMALITIES OF FETAL MEMBRANES AND AMNIOTIC FLUID
Abnormalities of fetal membrane
1. staning - is obvious within 1 to 3 hr. after meconium passage if the meconium has passed many days before delivery the staning becomes light green or brown.
-the membrane usually appears diffusely opaque due to neutrophil infiltration.
3. RETROMEMBRANOUS HGE
-the hemorrhage occurred days before delivery. The pigment in the membranes maybe brown or yellow.
1. amnion nodosum - these usually Appears as small nodules on the membrane, seen in pregnancies with oligohydamnios. Microscopy discloses these nodules to be formed of desquamated skin cells
2. Squamous metaplasia -appear as white nodules under
the amnion, not in the surface.
c. Placental insertion
-occurs when the membrane insert into the placental surface in a curved border of folded membranes at the margin.
-this folds elevates the membrane in a White rim above the placental surface, antepartum hemorrhage, preterm delivery, perinatal deaths, and fetal malformation were reported To be increased for pregnancies with this placental type.
2. Marginal Insertion
- more common
-the membrane insert into the lacental discs at its margin
- another variant of this circummaginate occurs when the membrane insert away from the placental edge and extend beyond the vascular plate into a white fibrin at the placental edge.
DISORDERS OF AMNIOTIC FLUID
-early in the second trimester the vol occupied by the fetus is about equal to the vol. of the amniotic fluid.
- The fetus does not appear confined within the uterus seen to move freely in a bath of fluid
-Throughout the 2nd and 3rd trimesters,the vol. of the fetus increase in comparison to the vol. of the fetus , and late pregnancy the amount of fluid , and late in pregnancy the amount of fluid appears small in comparison with the fetus.
-normally, amniotic fluid vol. reaches about 10000 ml by 36 weeks, but decreases thereafter
Sonogram has made objective measure of amniotic lluid possible. Two routinely used objective methods are :
1. measurement of a single vertical (SVP) pocket or fluid
2. calculation of the amniotic fluid index .
-The SVP is obtained by measuring the antero- posterior dimension (depth) of the largest pocket of amniotic fluid void of fetal parts or umbilical cord.
-a pocket measuring 2-8 cm is considered normal.
-The AFI is calculated by dividing the
uterus Into four equal segments and
measuring the largest pocket of fluid
(antero posterior measurement excluding