Project Details

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The aim of this study is to learn more about the effects of swine flu and its treatment on pregnant women and their babies.

Swine Flu (H1N1 Influenza) is a new type of Influenza A virus that causes flu symptoms in humans. Unlike ‘seasonal flu’ that occurs every winter and is caused by viruses that are very similar, the H1N1 virus is different from previous flu viruses. This means that very few people have natural immunity or resistance to it. As a result, swine flu has spread quickly and has affected a large number of people across the world in a short space of time.

Because the H1N1 virus is new, little is known about its effects. Information obtained from monitoring people affected with Swine Flu over the past few months suggests that most people are mildly affected and recover within one week. Certain groups of people, including pregnant women, are however known to be at increased risk of developing more serious problems. Unfortunately, very little scientific evidence is available regarding the exact risks of swine flu to pregnant women, and whether they are any different from those of seasonal flu. Information is also lacking about the effects that swine flu infection or its treatment with antiviral medication during pregnancy has on the developing baby.

This study aims to collect as much information as possible from throughout the UK about women who develop flu like symptoms at any stage of their pregnancy, or who take antiviral medication during pregnancy. This information will be collected through doctors and midwives at general practices and in hospitals. Women will be asked for their consent to participate in the study; women who agree to take part will be tested for H1N1, and we will collect information about any treatment they receive in pregnancy and how the infection affects them and their pregnancy. By studying a large number of pregnant women, it may be possible to identify whether certain groups of pregnant women are more at risk of the more severe problems caused by swine flu, and whether any particular additional treatment in pregnancy helps lessen these risks. This information will be used to help guide the treatment of pregnant women affected with swine flu over the rest of this pandemic. Information will also be collected at birth on the health of babies born to women in this study and will be compared to the health of babies born to women without swine flu or antiviral treatment during pregnancy. These details will help clarify whether swine flu or antiviral treatment in pregnancy increases the risk of having a baby with a birth defect or other problems.

The teams conducting the study are well positioned to carry out this study as both conduct ongoing research about the effects of medication in pregnancy (University of Newcastle) and of severe illness in pregnancy (University of Oxford). They are linked with wide groups of doctors and midwives who will be contributing information for the study. The costs requested include the costs of collecting the information, staff to administer the information collection as well as researchers to analyse the information and produce guidance for doctors and midwives on treating swine flu in pregnancy. The NHS costs are sought to cover the time required for doctors and midwives to provide information for the study and to women taking part.

Influenza infection during pregnancy is associated with adverse maternal and fetal outcomes, including probable increases in the risk of maternal pneumonia and possible increases in risks of certain congenital malformations. Recent US H1N1 pandemic experience as well as data from previous influenza pandemics indicates higher morbidity and mortality among pregnant women. 

DESIGN: Systematic review and a subsequent prospective observational cohort study using several different sources to identify pregnant women needing treatment or prophylaxis. Information about pregnancy management and outcomes will be collected directly from heath professionals, as well as women themselves where infection is managed in primary care.

COHORT IDENTIFICATION: All women in the UK identified with confirmed or suspected influenza H1N1v or requiring antiviral prophylaxis, identified through the UK Teratology Information Service (UKTIS), the Reproductive Medicine and Childbirth Research Network, the Primary Care Research Network, the HPA Regional Microbiology Laboratory Network, self reporting by patients and active negative surveillance through the UK Obstetric Surveillance System (UKOSS). Information about comparison women will be obtained from the existing UKOSS database of over 1200 women giving birth in the UK.

VIROLOGICAL CONFIRMATION OF H1N1: Women will undergo H1N1 testing arranged through the research network staff or by a self testing kit if not done already.

DATA GATHERING: 1. Consenting women identified through UKTIS will be contacted by telephone (a) two weeks after the reported exposure/ first contact. Details of them and their illness will be collected (b)  Patients who remain unwell will be followed up at two weekly intervals until recovery (c)  Final follow up will be of maternal and pregnancy outcome two weeks after birth.  2. Nominated UKOSS reporting clinicians will report anonymised details of all pregnant women admitted with confirmed or suspected H1N1v infection via a specific web-based rapid reporting and data collection system.

STUDY SIZE: We anticipate identifying 500-1000 affected pregnancies during the 6 month initial study period. Information on 1200 comparison women is available from existing UKOSS data.

ANALYSIS: We will investigate the relationship between demographic, pregnancy characteristics, management and clinical outcomes in order to generate immediate recommendations for changes in practice to improve outcomes for this vulnerable group.