Placentomegaly and placental mesenchymal dysplasia

Abstract

SUMMARYA 23-year-old primigravida presented to the labour ward at 37 weeks gestation referred with intrauterine growth restriction, oligohydramnios and placentomegaly. Differential diagnoses of placentomegaly were considered. Her antenatal blood screening tests were normal. There were no fetal malformations. However, triple screen and fetal karyotype were not done as patient presented late in pregnancy. The patient soon went into spontaneous labour and delivered a girl weighing 2.15 kg with a normal Apgar score. The cord was long and twisted; placenta was bulky, 1.7 kg, with prominent grape-like vesicles involving whole placenta with a rim of normal placenta at the periphery. Microscopy showed some areas of multiple villi with marked hydropic changes and myxoid degeneration, preserved vasculature and no trophoblastic proliferation. Placental mesenchymal dysplasia was thus diagnosed. The baby had no evidence of Beckwith-Wiedemann syndrome. The child is now 3 years old with normal development and is doing well. BACKGROUND

Prospective risk of stillbirth in women with placental mesenchymal dysplasia

“…Only 25 (22.9%) women had full‐term (GW ≥ 37) live‐born infants (Fig. ) . Of the 25 infants born to these women, including one with an unspecified birthweight, 15 (60%) were documented to be born with a low birthweight < 2500 g (six were < 2000 g) …”

“…The search term ‘placental mesenchymal dysplasia’ yielded a list of 88 published reports. Of these, 50 were included in the present analysis because information was available regarding individual data on PMD pregnancies with GW ≥ 24 in the English language . In addition, a further 13 reports that appeared in the reference lists of pertinent reports were also included in our analysis.…”

“…We identified a total of 63 reports describing a total of 107 PMD pregnancies with GW ≥ 24. These included 50 dealing with single cases, eight with two cases, one with four cases, one with five cases, two with nine cases, and one with 14 cases …”

Clinical manifestations of placental mesenchymal dysplasia in Japan: A multicenter case series

“…Elevated MSAFP or MShCG levels among patients with PMD have been extensively reported 6,9–11 . Alpha‐fetoprotein is thought to be transported extraordinarily from the fetus to the maternal circulation because the abnormal placental vessels in PMD are highly permeable 3,12 .…”

Single‐nucleotide polymorphism‐based chromosomal microarray analysis provides clues and insights into disease mechanisms

“…The Kagami–Ogata imprinting disorder, described in the second case, first manifested as very abnormal maternal serum analytes (hCG and AFP). This was the first indication of an imprinting disorder, followed by placentomegaly, another sign regarding placental function that may be indicative of an imprinting disorder among various other etiologies. We advise that highly abnormal maternal serum analytes should raise the degree of suspicion, beyond aneuploidy and neural tube defects, into the realm of imprinting disorders, as they may represent dysfunctional placenta.…”