[Associations between birth weight and placental volume in the first trimester].
BACKGROUND
Associations between the size of the placenta and birth weight have been described before. This connection has also been found in (sonographically estimated) second trimester placental size. The aim of this study was to find out if there are any differences in first trimester placental volume between various birth weight groups.


METHODS
Placental volume was obtained from non-smoking women at the end of the first trimester during a period of eight months. After birth, the newborns were divided into four groups: below the 10th, 10th to 50th 50th to 90th and above the 90th centile. As is known from previous research, placenta size changes in proportion to crown-rump-length. Therefore, the medians of the "placenta quotients" (placental volume/CRL) of each group were compared in order to correct for differences in gestational age.


RESULTS
Data from 1476 pregnancies could be evaluated. The overall median of the placenta quotient was 0.98. It was 0.85 in the group below the 10th, 0.92 between 10th and 50th, 1.02 between 50th and 90th and 1.10 above the 90th centile (p < 0.0001, median test).


CONCLUSIONS
The finding of associations between early pregnancy placental size and birth weight at term gives hope for the development of new diagnostic methods for the recognition of placenta-associated problems. Further research is required to estimate the clinical possibilities for the detection of pregnancies at risk of severe growth retardation and other conditions.
Ludwig-Boltzmann-Institut für klinische Geburtshilfe und Gynäkologie, Abteilung für Geburtshilfe und Gynäkologie, Donauspital am SMZ-Ost Wien, Germany. martin.metzenbauer@smz.magwien.gv.at
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Metzenbauer
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Hafner
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Hoefinger
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Schuchter
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Philipp
D001317:Austria; D001724:Birth Weight / Q000502:physiology*; D018568:Crown-Rump Length; D019160:Endosonography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007231:Infant, Newborn; D008297:Male; D010920:Placenta / Q000000981:diagnostic imaging*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012016:Reference Values; D016216:Ultrasonography, Prenatal