Placental thickness has been
observed as early as 14 weeks gestation in some cases of homozygous alpha-thalassemia
(1).
A thick placenta is present
in 90% of patients in one large series (1).
Thick placenta, fetal anemia
and hydrops may be present in fetuses affected with parvovirus B19 infection.
REFERENCES
Ko TM, Tseng LH, Hsu PM
et.al. Ultrasonographic scanning of placental thickness and the prenatal
diagnosis of homozygous alpha-thalassemia 1 in the second trimester.
Prenat Diagn 1995;15:7-10.