RT Book, Section
A1 Bianchi, Diana W.
A1 Crombleholme, Timothy M.
A1 D'Alton, Mary E.
A1 Malone, Fergal D.
SR Print(0)
ID 1106399668
T1 Ambiguous Genitalia
T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 978-0-07-144201-5
LK obgyn.mhmedical.com/content.aspx?aid=1106399668
RD 2024/04/25
AB Key  PointsIncidence  is  1  in  5,000  livebirths.  Most  common  cause  is  congenital  adrenal  hyperplasia  (CAH),  resulting  in  a  virilized  genetic  female.  This  autosomal  recessive  condition  has  an  incidence  of  1  in  14,000  livebirths.Prenatal  classification  of  ambiguous  genitalia  is  based  on  cause.  Fetuses  can  be  virilized  genetic  females,  undervirilized  genetic  males,  or  true  hermaphrodites  with  both  ovarian  and  testicular  tissue  present.Sonographic  prenatal  diagnosis  of  ambiguous  genitalia  is  more  accurate  in  males.  Clitoromegaly  is  associated  with  false-positive  diagnosis  in  females.  The  presence  of  a  normal  fetal  uterus  after  19  weeks  is  strongly  predictive  of  a  virilized  genetic  female.Differential  diagnosis  in  a  virilized  female  includes  androgen  exposure  due  to  CAH  or  maternal  tumors.  An  undervirilized  male  may  be  due  to  defects  in  the  synthesis  of  testosterone  or  its  precursor,  androgen  insensitivity,  chromosome  abnormalities,  or  true  hermaphroditism.  Single-gene  disorders,  such  as  Smith–Lemli–Opitz  syndrome,  should  be  considered.Prenatal  management  should  include  fetal  karyotype  and  testing  of  7-dehydrocholesterol  (7-DHC)  levels  in  the  amniotic  fluid.  Delivery  should  occur  at  a  tertiary  center.Fetal  treatment  is  available  for  CAH  and  Smith–Lemli–Opitz  syndrome.Infant  sex  assignment  should  occur  after  birth  using  a  team  approach.The  role  of  genital  surgery  in  children  with  ambiguous  genitalia  is  controversial.Recurrence  risk  depends  on  the  etiology  of  the  ambiguous  genitalia.