Prenatal diagnosis of congenital rubella infection in the second trimester of pregnancy.
OBJECTIVE
This case report describes the clinical presentation, diagnosis and management of a case of acute rubella infection in the second trimester. The complex issues of prenatal diagnosis of a congenital rubella infection are discussed.


METHODS
A 30-year-old woman presented with a fine macular rash at 15 weeks' gestation. Laboratory testing included maternal rubella-specific IgG and IgM detection (booking blood and acute-phase sample) together with measurement of IgG avidity. Prenatal diagnosis at 19 weeks (amniocentesis) and 23 weeks (amniocentesis and fetal blood) was done using a reverse-transcriptase polymerase chain reaction to detect rubella-specific RNA. The fetal blood sample was also tested for rubella-specific IgM.


RESULTS
Maternal serological results confirmed an acute rubella infection at 15 weeks' gestation. Rubella-specific RNA and IgM were detected in the fetal blood taken at 23 weeks' gestation. However, no rubella RNA was detected in either of the amniotic fluid samples collected at 19 and 23 weeks.


CONCLUSIONS
In second-trimester rubella where risk of fetal damage is low, prenatal diagnosis can identify the rubella-infected fetus, allowing the parents to make a more informed decision about their options. The optimal sample for prenatal diagnosis is fetal blood as no rubella-specific RNA was detected in the amniotic fluid.
Tang
Julian W
JW
Department of Virology, Royal Free and University College Medical School, London, UK.
Aarons
Emma
E
Hesketh
Louise M
LM
Strobel
S
S
Schalasta
Gunnar
G
Jauniaux
Eric
E
Brink
Nicola S
NS
Enders
Gisela
G
D000328:Adult; D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry / Q000166:cytology; D000956:Antigens, Viral / Q000032:analysis; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000166:cytology; D005817:Genetic Counseling; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000379:methods*; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012410:Rubella Syndrome, Congenital / Q000175:diagnosis* / Q000276:immunology; D012412:Rubella virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*
D000956:Antigens, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral