Inadvertent vaccination during pregnancy generates a lot of anguish in patients who were unaware of their condition by the time they were immunized. The first reaction is to think that the baby will be severely affected by what all kinds of studies request to determine the amount of damage suffered. Some even consider a therapeutic abortion. The truth is that there is no evidence that commonly used vaccines generate fetal problems, not even those that contain living agents. Therefore, therapeutic abortion is totally contraindicated in these cases. Vaccines with non-living components are not a problem.

Types of vaccines

Vaccines without live agents, safe, can be used during pregnancy: Tetanus, Whooping Cough, Diphtheria, Hepatitis B, Pneumococcus, Haemophilus influenza, Influenza A and B, Influenza H1N1, Meningococcus, HPV

Vaccines to live agents, contraindicated during pregnancy but without evidence of fetal harm: Rubella, Measles, Yellow Fever, Varicella (lechina), Typhus, Parotiditis, Polio, Rotavirus.

Viral bivalent, rubella and measles vaccine

• It is contraindicated in pregnancy and up to 3 months before (guideline for any live attenuated virus vaccine).
• It has not generated fetal lesions attributable to its viral components , even at the stage of greatest susceptibility (the first 3 months of pregnancy) when it has been placed inadvertently (it would never be placed if the presence of pregnancy was known).
• There are no reports of fetal injuries when members of the pregnant woman’s family were vaccinated.
• The interruption of pregnancy is not indicated by inadvertent vaccination before or during pregnancy.

Measles

Measles (natural infection, acquired by contact between people, respiratory secretions and saliva): Infectious and febrile disease and rash (produces a rash) caused by a measles virus. Fever, rash, cough and conjunctivitis.

Infectious period begins 4 days before the symptoms appear until 5 days after the eruption has appeared : incubation of 7 to 14 days, then fever appears and in 3 to 5 days the rash appears, the fever becomes very high and in 3 a 5 days after the fever disappears and the rash begins to disappear, therefore, the contagious period lasts approximately 14 days counted from day 4 before the fever appears until approximately when the fever disappears and the rash begins to disappear.

• Measles (natural) has never been shown to be the cause of fetal congenital malformations.
• It is possible that infection during the first trimester of pregnancy leads to early pregnancy loss (abortions) or preterm delivery in the third trimester.
• Primary measles infection at the end of pregnancy and very close to delivery can lead to neonatal measles in the newborn.
• There is no formal indication to interrupt a pregnancy affected by natural measles.
• There is no formal indication to terminate a pregnancy by inadvertent administration of the live attenuated vaccine.
• If you suspect you are pregnant or are considering doing so, do not get vaccinated.
• If you want to get vaccinated you should wait 3 months after vaccination to get pregnant.
• The risk of congenital malformations due to inadvertent vaccination is only theoretical, if there are no malformations due to the natural disease, there will be fewer due to vaccination with attenuated viruses.
• If the patient suffered measles before, the theoretical risk of malformations from the vaccine is even lower
• There is no problem for pregnancy or breastfeeding if children or other people in the household are vaccinated against measles.
• The pregnant patient not immunized against measles exposed to the natural disease (say, a child gets measles in school) should receive Immunoglobulins to limit the disease and complications of natural measles in adults.

Rasmussen SA et al. Obstet Gynecol 2015

Rubella

Rubella is an infectious disease with little or no symptoms produced by Rubella virus. Of giving symptoms these are discrete and manifest with malaise, swollen glands in the neck, mild rash and joint pains

Infectious period begins 7 days before the eruption appears (without it appears) and lasts up to 7 days after: Incubation 14-21 days, then discreet discomfort and swollen lymph nodes behind the ears and neck, the fever is very discreet, the rash appears on the 2 day of discomfort and lasts only 2 days. The contagious period lasts between 10 to 14 days, the problem is that in most cases we do not even know who is infected and infecting others (50% is asymptomatic and the same looks like a common cold or virus)

• The primary natural rubella infection during pregnancy is extremely harmful to the embryo (before 10-12 weeks of pregnancy): abortions, stillbirth, congenital malformations, heart disease, cataracts, deafness and neurological disorders
• After the 12th week of pregnancy, fetal period, deafness is the most common fetal damage.
• After week 17-18 the defects attributable to rubella are rare.
• The infection near or at the time of delivery even when it does not generate malformations can generate a severe neonatal picture.
• The theoretical risk of fetal injury due to vaccination against rubella during pregnancy is 1.6% but in practice there has not been an attributable case
• In two reports of 700 and 214 pregnant patients vaccinated during the first three months of pregnancy there were no malformations attributable to the attenuated rubella virus of the vaccine.
• There is no formal indication to terminate a pregnancy by inadvertent vaccination with Rubella virus.
• Pregnant women not immune to Rubella should receive immunoglobulins if exposed to the natural virus.
• Exposure to vaccinated persons does not create a risk in the pregnant woman.