The placentas were removed by a standard
method. Immediately after the childbirth, the umbilical
cord was clamped to ensure placental blood
drainage. The placental weight was measured using
a digital scale of 0.01 gram precision, the placental
thickness (t) was measured using a digital
caliper with 0.01 mm precision in three points and
then the mean was applied for estimation of the
total placental volume. The placental surface area
was determined using Cavalier`s point-counting
method by this formula: A=ΣP. A (p), where A is
estimation of the surface area, ΣP is the sum of the
number of points landing on the surface of placenta,
A (p) is the area associated with each point in
stereological grid. Then, total volume of each placenta
was estimated using this formula, V=A.t
(11), where V is estimation of the volume, A is
surface of placenta and t is the mean thickness of
placenta.