Isolated choroid plexus cysts—the need for routine offer of karyotyping

Abstract

The management of isolated fetal choroid plexus cysts remains controversial. We have prospectively studied 15,565 pregnancies at two large obstetric units for the presence of choroid plexus cysts. In all cases where cysts were present at 19 weeks' gestation or greater, and were multiple, bilateral or solitary and greater than 5 mm maximum diameter, women were offered amniocentesis or placental biopsy, irrespective of the presence or absence of other abnormalities. Choroid plexus cysts were present in 152 (0.98 per cent) of cases. Four cases (2.6 per cent) of autosomal trisomy (three of trisomy 18, one of trisomy 21) were detected on prenatal karyotyping. In all cases, choroid plexus cysts were the only detectable prenatal anomaly. This study and a review of other large studies do not support the view that isolated choroid plexus cysts are a benign variant, the risk of trisomy being 1 in 82. Until further evidence is available, we recommend that cases of isolated fetal choroid plexus cysts at 19 weeks' gestation or greater should be offered prenatal karyotyping.

Choroid Plexus Cysts

“…Consultation with a genetic specialist or high-risk obstetrician may be indicated. 19 Despite the low incidence of isolated CPC on prenatal sonogram, physicians must take into consideration the risk of aneuploidy; furthermore, physicians must understand the controversy regarding medical management of CPC. Until further studies are completed, the risks and benefits of genetic testing must be weighed against the risk of aneuploidy in light of modifying risk factors.…”

“…10,30 -33 However, cysts with diameters less than 5 mm may not be linked with trisomy 18, 14,19 and large cysts in excess of 10 mm may impart a higher risk. 16,34 Furthermore, the risk for trisomy 18 when compared with normal births has been shown to increase with the presence of CPC without any other sonographic abnormalities, ie, isolated choroid plexus.…”

“…In the second trimester, the incidence of CPC has been estimated by several population studies to be 1%, 3,4,[13][14][15][16][17][18][19] and other studies have found the incidence to vary from 0.18% to 3.6%. 20,21 Despite the low incidence, CPC has clinical implications for aneuploidy because of an association of choroid plexus with trisomy 18 2,[5][6][7][8][9][10][11][12]22 and trisomy 21.…”

“…20,21 Despite the low incidence, CPC has clinical implications for aneuploidy because of an association of choroid plexus with trisomy 18 2,[5][6][7][8][9][10][11][12]22 and trisomy 21. 4,10,13,19,[22][23][24] Researchers have been more concerned with trisomy 18 because the prevalence of CPC for fetuses with trisomy 21 and for the general population are the same. 13,23,24 Prenatal sonography in 44% to 50% of pregnancies with trisomy 18 show CPC, 15,16 whereas only 1.4% of pregnancies with trisomy 21 show CPC.…”

“…Many research studies have concluded that an isolated CPC is not an indication for genetic testing, 44 -47 whereas many other studies recommend genetic testing. 4,11,19,22,48 Interestingly, an individualized risk method had been proposed using maternal age, presence of an isolated CPC, and serum markers as modifying risk factor. If risk is greater than 1/200, amniocentesis is offered.…”