Maternal Immunisations

Pregnancy is a precious time for the whole family, especially to first time parents and to couples who have difficulty in conceiving ( IVF pregnancy or precious pregnancy ), to children looking forward to their new sibling, to grandparents and to other family members who are looking forward to a new addition to the family.

Whatever it is, parents should always put their best foot forward to give the new life a good head-start. This will include doing everything possible to make the pregnancy outcome as good as possible – healthy diet, exercise, avoiding bad habits, etc.

Immunisation of the mother to prevent infectious diseases and passing on the good antibodies made to the baby has been recognised as an important part of this prevention exercise.

Two important vaccinations have been supported by data and is highly recommended in pregnancy.

Pregnancy has been recognised to be a physiological state whereby there are anatomical and physiological, immunological and hormonal changes to the mother’s body which are necessary to support the developing baby. These changes result in an altered state of immunity and predisposes the mother to certain infections as well as more adverse outcomes. The relationship between infection and fetal outcome is a 2 way one : Pregnancy predisposes a mother to certain infections and infections in turn causes increased risk to fetal outcomes.

Pertussis ( whooping cough ) vaccination

Most of us have been vaccinated against whooping cough as children but most adults do not receive a booster after leaving school. In recent years, there have been a resurgence in whooping cough in many countries including Singapore. The incidence in children under one year old is particularly significant as they do not handle the infection well and can succumb to the disease. Newborne babies do not have immunity to whooping cough and are only vaccinated at 3,4, 5 months before they make protective antibodies. In other words, they do not have immunity in the first 6 months of life. Maternal vaccination enables passive transfer of these antibodies from mother to baby until they can make their own antibodies.

Pregnant women should get vaccinated from 27-36 weeks of pregnancy to enable high levels of antibodies which can be transferred to their babies. Statistics have shown that this practice of maternal vaccination have resulted in protection of newborne babies to whooping cough by 90%.

Therefore, all mothers should be vaccinated in the 3 rd trimester of each pregnancy to protect their newborne babies from pertussis. If they are going to have 5 babies, they should be vaccinated at each pregnancy ( i.e. 5 times )

Influenza vaccination

Influenza in pregnancy has been known to have higher morbidity and worse outcome. The pregnant state compromises lung capacity and later stage pregnancy influenza confers greater adverse outcome to both mother and baby. Influenza vaccination should be done anytime during the second trimester and particularly during the flu season each year regardless of whether the mother is healthy or not.

Currently, the takeup rate of such vaccinations in Singapore is low due to multiple factors, one of which is low awareness and the reluctance to have vaccination due to worry about side effects to the pregnancy outcome. Flu vaccination is safe during pregnancy and the statistics show that this can reduce flulike illness in pregnancy and reduction in maternal morbidity and mortality which translates to better fetal outcome as well.