* Primary infection in the first 4 months (16 SA) pregnancy poses a risk of serious embryofœtopathies after this period the risk of teratogenicity is zero.
The risk of fetopathy is maximal between 15 and 20 SA (intrauterine growth retardation “IUGR,” mental retardation, cataracts …).
* During pregnancy the rubella serology is systematic and must be repeated at 4 months of pregnancy in case of negative prior to serology.
* In the immediate périconception the risk of transmission is almost zero then it is 80% up to 12 SA and declines in Q2 (25% at the end of Q2), the risk becomes very important in the 3rd quarter (90% ).
* The foetopathy can manifest microcephaly, mental retardation, IUGR and congenital deafness, at the end of Q2: late abortion, death in utero, IUGR.
* Biological syndrome of fetal infection associated thrombocytopenia, anemia, erythroblastosis, elevated GGT and high interferon.
The IgM are produced by the fetus from the 20th SA.
Congenital rubella syndrome (Gregg triad)
– Eye: microphthalmia, cataracts, chorioretinitis, glaucoma
– Ear: cochlear damage with risk of deafness
– Heart: patent ductus arteriosus and foramen ovale ++, CIA or CIV …
* Incubation lasts 14 to 18 days, the obvious invasion phase by a flu-like syndrome, rash disappears in 3 days.
The infectious period is from 8j before and after the eruption 8d.
IgG dice appear rash and persist indefinitely, a rate> 1/20 is considered positive, can lead to reinfection IgM new increase but will be absent.
IgM dice appear rash and lasts 6-8 weeks, but sometimes several months.
Antenatal diagnosis of certainty is based on amniocentesis (achieving at least 6 weeks after seroconversion) with virus detection by PCR.
* During pregnancy testing is mandatory and based on the determination of IgG achieved in the first quarter.
The presence of IgG> 1:20 says the former immunity and eliminates the risk of congenital.
A negative serology is retested at 16 or 20 weeks (useless beyond).
* CAT to suspicious rash in the first quarter: the first collected serum (S1) and a second serum 15 days later, rubella primary infection is likely to negatively S1 and S2 positive (IgG) / Positive S1 and S2 ascent or Ig M +.
* CAT if contagion rubella in the first quarter: if Ig G (S1) are negative, you have taken the second serum after 3 weeks, if S2 is positive primary infection is likely (look for Ig M).
* Beyond 16 SA, there is no risk of severe malformation and suffie ultrasound monitoring.
