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Infections in pregnancy can have far reaching consequences.
Prevention is desirable. It is therefore desirable to have a
good knowledge of immunization. Pregnant mothers are at an equal
risk of contracting any infection as her non-pregnant
counterpart, if not more. Also, in pregnancy there are
situations where extra protection is desirable. In pregnancy,
the immunization demanding situations are
–
Grave risk to mother and fetus due to infection.
–
Exposure of the mother or other family members to the diseases in
pregnancy.
–
Epidemic
–
Voluntary prophylaxis.
Infections can have a far-reaching effect on the fetus too.
These include teratogenic effects, organ/tissue damage,
placental infection, persistent neonatal jaundice,
hydrocephalus, microcephaly congenital vascular diseases,
congenital deafness and others. The obstetric effects of
infections include abortions, preterm delivery, IUGR, birth
asphyxia, sick and morbid newborn. It is therefore
understandable to prevent any maternal infections from causing
devastation. Immunization in pregnancy is one such measure.
Different types of vaccines available include attenuated live
vaccines, inactivated vaccines, immunoglobulins, and new
technology-based vaccines. The therapeutic vaccines include
tetanus, gas gangrene, diphtheria, anti-snake venom, botulism
and others. Inactivated Vaccines are generally safe in
pregnancy. Vaccines against bacterial infections are usually of
these types.
Attenuated live vaccines: They give active immunity. However the
small near theoretical risk of transferring infection remains.
But the benefits should be weighed against the risk involved.
They are thus best avoided in first 12 weeks and last month of
pregnancy. Common vaccines used for prophylaxis in pregnancy are
tetanus toxoid, Cholera and Typhoid during epidemics.
Two most influential vaccines that have affected positively are
1) Tetanus and 2) Anti- D Vaccine. These two have given a
spectacular result in their respective areas of protection.
Tetanus Toxoid: The schedule currently recommended is:
§ In first pregnancy two doses, four to six weeks apart.
§ In next pregnancy is within two years one booster dose is enough.
§ If more than two years have passed before the next pregnancy, two doses
are recommended.
Undoubtedly, tetanus toxoid has changed the face of maternal and
neonatal tetanus. Amidst, a fear of increased ABO in
compatibility due to tetanus toxoid was expressed. However the
risk is reduced with more pure preparations. Also, the benefits
far outweigh the risks in favour of administration.
Hepatitis B: It is recommended for pregnant woman coming in
contract of affected person or endemic areas. Recombinant
Hepatitis B surface antigen is to be given in 3 doses of 1 ml IM
(20 mg). First and second dose is to be given one-month apart
and third six months after. Prophylactic gamma globulin (16.5%
0.04ml/kg) is also recommended for administration for exposure
to HAV infections and HBIg for HB vaccine administered for HBV
exposure. These are having a significant protective effect.
For subjects who are “pregnant to be”, Rubella and
Hepatitis vaccines are recommended. Rubella: Primary active
immunization of pre school children and vaccination of “pregnant
to be”. Live attenuated vaccine confers long lasting immunity in
about 95% receivers. Rubella vaccine is not recommended for a
pregnant lady. However in case of an inadvertent exposure to the
vaccine, termination is not recommended.
Anti-rabies vaccine is recommended even in pregnancy as benefits
outweigh the risks and so should be given.
Summary of recommendations of immunization during pregnancy:
Live
virus vaccine:
Measles:
C.I.
Mumps:
C.I
Polio:
Not routine
Yellow
Fever: On travel
Inactive
virus vaccine:
Influenza: Voluntary
Rabies:
same as non-pregnant.
Hepatitis
B At high risk and –ve for BAg
Inactivated Bacterial Vaccines:
Pneumococcal pneumonia: same as non –pregnant
Typhoid:
Travel
Plague:
Selective vaccination of exposed persons.
Hyper
immunoglobulin:
Hepatitis
B: Post exposure prophylaxis along with HB vaccine initially and
then vaccine alone at1 and 6 months.
Rabies:
Post exposure prophylaxis
Tetanus:
Post exposure prophylaxis
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