Fractal analysis of the maternal surface of the placenta: preliminary report.
OBJECTIVE
The objective of this study was to determine whether the maternal surface of the placenta is fractal, and whether the mean fractal dimension differs according to the gestational age and clinically or pathologically different conditions.


METHODS
Using digitized images of the maternal surface of 75 placentas, fractal dimensions were measured with a fractal analysis software.


RESULTS
The mean fractal dimension of the maternal surface of the placentas significantly exceeded the topological dimension of a surface (= 2). This means that the morphological pattern of the maternal surface fulfills the mathematical definition of fractal structures. Among the three different groups of gestational age, the mean fractal dimension in 22-29 weeks was significantly lower than that in 30-36 and 37-41 weeks (p = 0.022 and 0.014, respectively). Although not significantly different (p = 0.149), in 30-36 weeks the mean fractal dimension of the placentas complicated by pregnancy-induced hypertension (PIH) was greater than that without PIH.


CONCLUSIONS
Fractal geometry, a vocabulary of irregular shapes, can be useful for describing quantitatively the architecture of the maternal surface of the placenta and become a useful tool for analyzing physiological and pathological placental formation mathematically.
Shiba
Masahiro
M
Department of Obstetrics, Center for Perinatal Medicine, Nagano Children's Hospital, Nagano, Japan.
Kikuchi
Akihiko
A
Hara
Kikue
K
Sunagawa
Sorahiro
S
Yoshida
Shiro
S
Takagi
Kimiyo
K
Ogiso
Yoshifumi
Y
D000293:Adolescent; D000328:Adult; D005260:Female; D017709:Fractals; D005865:Gestational Age; D006801:Humans; D008954:Models, Biological; D010781:Photography; D010920:Placenta / Q000033:anatomy & histology / Q000473:pathology*; D010922:Placenta Diseases / Q000473:pathology*; D011247:Pregnancy; D011248:Pregnancy Complications; D012189:Retrospective Studies