BMJ: Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study

[tetano]

BMJ 2011; 342:d3214 doi: 10.1136/bmj.d3214 (Published 14 June 2011)
Cite this as: BMJ 2011; 342:d3214

Research

Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study

Abstract

Objectives To follow up a UK national cohort of women admitted to hospital with confirmed 2009/H1N1 influenza in pregnancy in order to obtain a complete picture of pregnancy outcomes and estimate the risks of adverse fetal and infant outcomes.

Design National cohort study.

Setting 221 hospitals with obstetrician led maternity units in the UK.

Participants 256 women admitted to hospital with confirmed 2009/H1N1 in pregnancy during the second wave of pandemic infection between September 2009 and January 2010; 1220 pregnant women for comparison.

Main outcome measures Rates of stillbirth, perinatal mortality, and neonatal mortality; odds ratios for infected versus comparison women.

Results Perinatal mortality was higher in infants born to infected women (10 deaths among 256 infants; rate 39 (95% confidence interval 19 to 71) per 1000 total births) than in infants of uninfected women (9 deaths among 1233 infants; rate 7 (3 to 13) per 1000 total births) (P<0.001). This was principally explained by an increase in the rate of stillbirth (27 per 1000 total births v 6 per 1000 total births; P=0.001). Infants of infected women were also more likely to be born prematurely than were infants of comparison women (adjusted odds ratio 4.0, 95% confidence interval 2.7 to 5.9). Infected women who delivered preterm were more likely to be infected in their third trimester (P=0.046), to have been admitted to an intensive care unit (P<0.001), and to have a secondary pneumonia (P=0.001) than were those who delivered at term.

Conclusions This study suggests an increase in the risk of poor outcomes of pregnancy in women infected with 2009/H1N1, which reinforces the message from studies of maternal risk alone. The health of pregnant women is an important public health priority in future waves of this and other influenza pandemics.

full article

http://www.bmj.com/content/342/bmj.d3214.full

 

[tetano]

Re: BMJ: Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study

BMJ 2011; 342:d3237 doi: 10.1136/bmj.d3237 (Published 14 June 2011)
Cite this as: BMJ 2011; 342:d3237

Editorial

H1N1 influenza in pregnant women

K S Joseph, professor,
Robert M Liston, professor

+ Author Affiliations

1Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada V6H 3N1

kjoseph@cw.bc.ca

Vaccination is the key to mitigating the higher incidence of adverse outcomes

Although the 2009 H1N1 pandemic proved to be more benign than anticipated, it had a substantial effect on pregnant women. In the linked cohort study (doi: 10.1136/bmj.d3214 ), Pierce and colleagues report the perinatal outcomes of 256 pregnant women admitted to hospital with H1N1 influenza in the United Kingdom. 1

The study found that pregnant women admitted to hospital with H1N1 influenza had significantly higher rates of adverse pregnancy outcomes than uninfected pregnant women. These included three to four times higher rates of preterm birth, four to five times higher rates of stillbirth, and four to six times higher rates of neonatal death. 1 These high rates of adverse perinatal outcomes were consistent with those reported in a population based study from the United States, 2 which also found a high maternal death rate (five deaths in 489 pregnant women admitted to hospital). Presumably, details of specific maternal complications and causes of death will be forthcoming ?
[Full text of this article]

http://www.bmj.com/content/342/bmj.d3237.short