H1N1 IN PREGNANCY

Pregnant women, especially those with co-morbidities, are at increased risk for

complications from all forms of influenza virus infection – seasonal, zoonotic, and
pandemic. Influenza in pregnancy is associated with an increased risk of adverse
pregnancy outcomes, such as spontaneous abortion, preterm birth, and fetal distress.

Based on available information, the World Health Organization (WHO) has identified

the groups that are at increased risk for complications and severe disease from
pandemic influenza A (H1N1) 2009 virus infection as including pregnant women and
infants and young children <2 years of age.

Pregnant women appear to be approximately 4-5 times more likely to develop

severe disease, when compared to non-pregnant individuals in the general
population, and this risk is highest in the third trimester. Infants and young children
(particularly those <2 years of age and those with underlying chronic medical
conditions) have the highest rate of influenza-associated hospitalization. Available
data demonstrate that hospitalization rates for children aged <5 years were

consistently reported to be at least 2-3 times that of other age groups.1

This document provides guidance for the protection and care of women during
pregnancy, childbirth and the postpartum period, and of their newborn infants, from
influenza virus infection at home, in public places, in the workplace, and in healthcare
facilities. It aims to make available in one concise document all guidance on
pandemic influenza A (H1N1) 2009 virus infection relevant to this programmatic area.

In this document, the first part provides general guidance for pregnant women and

their newborn babies during the pandemic. The second part offers considerations for
pregnant women working in the health-care services. The last part discusses the care
of women, during pregnancy and post partum, and their newborn babies, including
those with HIV, who have suspected or confirmed pandemic (H1N1) 2009 virus
infection

Introduction

Maternity services are among the essential services that need to be ensured during

the pandemic. The greatest challenge for organized childbirth services will be at the
peak of pandemic virus circulation in a country, when staff members also may be ill
and the complication rates among pregnant women or those undergoing childbirth
will be highest.

During a pandemic, there are women who are not yet aware that they are pregnant.

Therefore, it is important that all women of reproductive age receive information
about preventive measures against pandemic influenza. Ideally, prior to the arrival of
pandemic influenza, health programme managers should discuss preventive
measures with groups in the community and engage them in sharing this
information and supporting community members, especially pregnant women, in
applying these measures.

Signs and symptoms of pandemic (H1N1) 2009 virus infection

The spectrum of disease caused by pandemic (H1N1) 2009 virus is broad and ranges

from non-febrile, mild upper respiratory tract infection to severe or fatal pneumonia.
To date, most cases appear to have uncomplicated, self-limiting typical influenza-like
illness. Symptoms include sudden onset fever (typically >38°C), cough, sore throat,
malaise, muscle/joint pain, and headache. Gastrointestinal symptoms (nausea,
vomiting, and/or diarrhoea) may also exist.

Special considerations for pregnant women and newborns:

• Compared to non-pregnant individuals in the general population, pregnant

women are more likely to develop influenza-associated complications, severe

 

disease, and death, especially if they have co-morbidities

• Influenza in pregnancy is associated with increased risk of adverse pregnancy

outcomes such as spontaneous abortion, preterm birth, and fetal distress.

• The risk of complications in newborn infants increases, if their nutritional status

is poor and fluid intake is low because of prolonged vomiting, diarrhoea, or
inability to feed.
 

• Newborn infants less frequently present with typical influenza signs, such as

cough and fever.9 Influenza or its complications in newborn infants may

manifest as apnoea, low grade fever, fast breathing, cyanosis, excessive

sleeping, lethargy, feeding poorly, and dehydration. Illnesses caused by
influenza virus infection in newborn infants are difficult to distinguish, based on
signs alone, from illnesses caused by other respiratory pathogens, e.g.
respiratory syncytial virus. Delay in identifying the cause of respiratory illness in
newborn infants can lead to additional complications, and therefore,
differential diagnosis should include influenza virus infection where its
circulation in the community is known.