Obstetric outcomes of influenza A H1N1 (2009) infection in pregnancy--experience of a Singapore tertiary hospital

Abstract

Introduction: Influenza A H1N1 (2009) pandemic has affected countries worldwide including Singapore. Data on obstetric outcomes of women with H1N1 (2009) in pregnancy are lacking.

Materials and methods: This was an observational study analysing the obstetric outcomes of pregnant women with influenza A H1N1 (2009) infection who had delivered at a viable gestation (24 weeks or more) in our centre.

Results: Between 23 June 2009 and 30 September 2009, 235 pregnant women were diagnosed with influenza A H1N1 (2009) at our centre, with 42 having delivered and comprising the study cohort. Median age was 27.5 years (range, 16 to 42). Multiparous women comprised 59.5% (25/42) whilst 40.5% (17/42) were primiparous. In terms of ethnicity, 61.9% were Malays, 26.2% Chinese, 4.8% Indians and 7.1% Others. All women received oseltamivir. All had shown recovery from the acute influenza infection. There were no respiratory complications. Twenty-nine women (69.0%) delivered at term. Twenty-fi ve women (59.5%) had spontaneous labour whilst 15 (35.7%) had labour induction. Two women (4.8%) did not labour. Thirty-six women (85.7%) had vaginal delivery, of whom 3 were instrumental deliveries. Apgar scores of greater than 8 at 1 min and 5 min were documented in babies of 95.2% (40/42) women, respectively. Thirty-two women (76.2%) delivered babies with birthweights greater than 2500 g. Compared with historical data from 2008, the H1N1 cohort had comparable mean birthweight and average gestational age at delivery of 38 weeks.

Conclusion: Our study suggested that obstetric outcomes were not adversely affected by influenza A H1N1 (2009) infection.