Contents
What is rubella?
It is a contagious disease caused by a virus that spreads through the respiratory tract or through saliva and which then passes into the blood. The manifestations of the infection are not very specific, sometimes even invisible, which makes it easy to ignore that you are sick. They appear 14 to 20 days after encountering the virus. In 50% of cases there is a slight rash that begins on the face, then spreads to the trunk and limbs, then disappears within three days without scarring. There are some signs that appear a few days before the rash that can put an eye on you, but they are not constant. Those are lymph nodes, moderate fever, headache, conjunctivitis or joint pain. Warning ! A week before the first signs appear, we are already contagious and this persists even when they have stopped (about 10 days).
Rubella in childhood
Like mumps and measles, Rubella is a highly contagious viral infection, most commonly occurring in children between the ages of 5 and 9. Once we have it, we are safe: it confers good immunity. 94% of pregnant women are thus protected by the antibodies they produced either during their childhood when they contracted the virus, or following the vaccine.
What is the screening for rubella in pregnant women?
In a pregnant woman, the rubella screening is one of the mandatory exams. It is prescribed during the first prenatal visit (unless written results prove immunity). It consists of dosing antibody also called immunoglobulins (Ig G) by means ofa simple blood test. A positive IgG result above a certain threshold confirms that the mother-to-be is immune and has encountered the virus once in her life, or while she is vaccinated. In this case, expectant mothers can rest easy. To avoid taking any risk, a second sample is scheduled a fortnight later. It is then checked that the level of IgG antibodies has not changed.
When there is no IgG in the mother’s blood, it means the mother is not immune. Caution is therefore required and monthly monitoring of antibodies is instituted until the fourth month of pregnancy to ensure that there is no ongoing rubella. After this date, serological surveillance is no longer necessary because the risk of malformations or complications due to this disease are non-existent. When the result is doubtful (too much IgG or significant variation between the two samples of the IgG level), the laboratory looks for another antibody, IgM, present only in the event of recent infection.
Namely
Warning ! Unless a blood test is taken, the diagnosis of rubella is rarely confirmed with certainty. Indeed, the symptoms – slight fever, headache, rash on the neck and face of small pink spots – can resemble other viral diseases (such as measles) or even go unnoticed. Even if the manifestations disappear in three or four days, the consequences on the fetus will be particularly severe. So we remain vigilant in the event of a fever and we rush to your doctor at the slightest bizarre symptom!
Pregnant rubella: what to do if the test is positive? What support ?
Is the transmission of rubella to the unborn baby systematic?
The risk of spread of virus to baby (placental) varies depending on the stage of pregnancy. It is very important during the first trimester (60 to 90%), decreases in the second (25 to 60%) and reaches 100% in the third trimester.
Rubella during pregnancy: how do you know if the fetus is infected?
For a definite diagnosis, an amniocentesis is proposed after 18 weeks. She is studying the genome of the virus in the amniotic fluid. A fetal blood puncture around 22 weeks allows the determination of antibodies specific to a recent infection. Finally, ultrasound monitoring will be set up in a specialized center in order to identify fetal damage.
Rubella and pregnancy: what happens if the baby is affected?
Transmission of infection from mother to fetus occurs through the placenta (congenital rubella), causing a major risk of malformations.
Before 12 weeks, an abortion is generally offered to parents given the severity of the malformations. Then and up to 18 weeks, the risk of serious damage is reduced. The mother will be followed in a prenatal diagnosis center and decisions will be made on a case-by-case basis depending on the child’s condition. Fortunately, low number of babies born with congenital rubella (less than 1 / 100 births).
Is there a treatment for rubella?
There is no cure. Only vaccination protects effectively. Thanks to vaccination and increased surveillance of pregnant women, cases of rubella during pregnancy are falling sharply (21 cases in 2001 and 2 in 2009).
The vaccine (based on live attenuated virus) cannot be given during pregnancy. Women of childbearing age and unimmunized adolescent girls are therefore advised to get vaccinated before pregnancy and be on contraception for two months after vaccination. Moms who have just given birth and who are not immunized can be vaccinated after childbirth during the stay in the maternity hospital. This will avoid many worries during a future pregnancy. The ideal being of course to vaccinate all children (girls and boys) from 1 year old to prevent them from infecting a pregnant woman. The vaccine is then combined with that against measles and mumps.