• Users Online: 33
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2017  |  Volume : 5  |  Issue : 2  |  Page : 69-72

Retrospective analysis of maternal and foetal outcome of H1N1 influenza amongst antenatal mothers at a tertiary care hospital

Department of Obstetrics and Gynaecology, Sri Ramachandra Medical College, Chennai, Tamil Nadu, India

Date of Web Publication19-Jan-2018

Correspondence Address:
Dr. Manipriya Ravindran
Department of Obstetrics and Gynaecology, Sri Ramachandra University, Chennai - 600 116, Tamil Nadu
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jpsic.jpsic_22_17

Rights and Permissions

Background: Pregnancy is an immunocompromised state where in infections are common. H1N1 (hemagglutinin type 1 and neuraminidase type 1) Influenza is a seasonal epidemic, considered as an alarming infection across the world with high rates of maternal mortality each year. The principal intention of this study was to elicit the clinical profile of antenatal mothers with H1N1 and subsequently to analyse the risk factors, prognosis and the materno-fetal outcome. Extensive review of literature with current guidelines and management protocols has been highlighted.
Methodology: This is a retrospective observational study performed in Sri Ramachandra University and Research Institute over the period of one year from January 2016 – March 2017, the clinical course of the patients who were confirmed with H1N1 influenza using throat swab RT-PCR assay was analysed. Statistical analysis was done by SPSS, version 11.
Results: A total of 62 antenatal patients with symptoms suggestive of H1N1 influenza were tested for H1N1 out of which 12 were positive, which accounted for 19.35% positivity. The mean age was 24 years with a range of 22-30 years. The epidemic peaked in the month of November to January. Fever with cough was the most common clinical manifestation. Most of the patients were hospitalized and treated with oseltamivir. All the positive patients, were advised home isolation for 5-7 days after discharge. This indexed study had an overall mortality rate of 8.3%. Acute respiratory distress syndrome and multiple organ dysfunction were the most common cause of death.
Conclusion: Most of the patients recuperated well with close vigilance, symptomatic and antiviral treatment, went on to deliver healthy baby. Proper prevention steps, personal hygiene and admission to designated swine flu ward can be helpful in preventing the spread in the community. Respiratory failure and sepsis were the cause of mortality among the patients of this study.

Keywords: Epidemic, H1N1 infection, materno-foetal outcome

How to cite this article:
Ravindran M, Gowtham S, Mehta P, Narayanan P. Retrospective analysis of maternal and foetal outcome of H1N1 influenza amongst antenatal mothers at a tertiary care hospital. J Patient Saf Infect Control 2017;5:69-72

How to cite this URL:
Ravindran M, Gowtham S, Mehta P, Narayanan P. Retrospective analysis of maternal and foetal outcome of H1N1 influenza amongst antenatal mothers at a tertiary care hospital. J Patient Saf Infect Control [serial online] 2017 [cited 2020 May 28];5:69-72. Available from: http://www.jpsiconline.com/text.asp?2017/5/2/69/223693

  Introduction Top

World Health Organisation has recognised pregnant women as a 'priority risk group' as the possibility of mortality and morbidity associated with infectious diseases is amplified in pregnancy due to the various physiological changes that take place to accommodate the developing foetus. H1N1 swine flu Influenza virus is known to cause annual seasonal epidemic in the Indian subcontinent with one or two new strains emerging each year, thus making it a challenge to the treating physicians. The first confirmed case of H1N1 in India was in Hyderabad in May 2009, and within a year time, there were reports of death of 1692 patients.[1] Pregnant women are more vulnerable with 18-fold higher risk of developing complication.[2] The infection has been related to the risk of developing spontaneous abortions, preterm birth and increased risk of foetal distress. Several studies have also shown an increased likelihood of low birth weight, perinatal mortality and the potential chance of developing congenital anomalies.[3],[4],[5],[6] Patients with co-existing medical conditions such as asthma or diabetes are 3–4 times greater risk of morbidity and mortality when compared to the non-pregnant counterparts with similar risk factors.[7] This indexed study was undertaken to observe the clinical profile of patients with confirmed H1N1 swine flu infection and the maternal and foetal outcome.

  Materials and Methods Top

This is a retrospective observational study conducted in the Department of Obstetrics and Gynaecology at Sri Ramachandra University and Research Institute. Retrospective data of confirmed cases of H1N1 swine flu were collected for the time period from January 2016 to March 2017 from Microbiology Department and subsequent patient data from the Medical Records Department (MRD). MRD in the hospital has the facility to retrieve case sheets with the diagnosis using International Statistical Classification of Diseases and Related Health Problems, with the search word of 'H1N1 swine flu influenza' code no J 10.1. Patients who were clinically suspected to have H1N1 swine flu were subjected to laboratorial analysis of throat swab real-time reverse transcriptase polymerase chain reaction assay. A standard request form, which was filled, included patient's demographic data, history, underlying medical condition and clinical signs and symptoms of the patient, and informed consent was obtained from the patient or from the relative. Only confirmed cases, managed either as inpatient or outpatient, were included in the study. The data collected were analysed for age, gender, a period of gestation, onset and duration of various symptoms, status of patient on admission, treatment efficacy and the maternal foetal outcome.

  Results Top

During the study period, screening for H1N1 influenza was performed for 62 pregnant patients who presented with signs and symptoms of influenza-like illness. Out of the 62 patients, 12 patients were positive for H1N1 influenza which accounted to 9.37%. The highest occurrence was observed in November 2016 to January 2017 with an overall positivity rate of 41%. The mean age group of the cohort was 24, with a range from 22 to 30. The gestational age at the time when the infection was obtained; one woman (12.9%) was in the first trimester, four women (33%) were in the second trimester and seven (58%) women were in the third trimester. Majority of the patients were stable during admission (81%) and two (18%) patients were critical. The most common presenting symptom was fever in nine patients (79%), followed by cough in eight patients (66%), four (33%) patients had rhinorrhoea, while three patients (25%) presented with complaints of breathlessness and sore throat and two patients (16%) complained of myalgia.

The mean duration of stay was 4 days with four (36%) patients staying for <4 days and seven (63%) were hospitalised for >4 days. Hypothyroidism (41%) was the most common co-existing medical condition, followed by diabetes (25%), anaemia (25%), asthma (8.3%) and seizure disorder (8.3%).

Hospitalisation was required for 11 patients (91%), 1 (9%) was managed as outpatient as she presented with mild illness after explaining the warning symptoms and signs. Oseltamivir phosphate was given for all patients in the recommended 75 mg dose twice daily for 5–10 days as per Centers for Disease Control and prevention guidelines, nine (75%) of them had early initiation of treatment, while three (25%) those who presented late had a delayed initiation of treatment. There were no serious adverse reasons such as vomiting, nausea, abdominal pain, diarrhoea, drowsiness and headache reported in the study group. Two (18%) out of the 11 patients who were admitted needed admission in the Intensive Care Unit and 1 (9%) of them required mechanical ventilation. One (8.3%) maternal death occurred during the study period. The cause of maternal mortality was respiratory failure secondary to pneumonia. Of the 11 patients, six of them went into labour wherein four of them delivered normally and two had emergency lower segment section due to foetal distress and cephalopelvic disproportion. One patient had spontaneous abortion at 23 weeks. Three were delivered by elective lower segment caesarean section. One patient was lost to follow up.

  Discussion Top

H1N1 swine flu influenza is a highly contagious pathogen with a high rate of mutation in haemagglutinin and neuraminidase antigenic epitopes, having eight RNA strands, one derived from human flu strain, five from swine strains and two from avian bird strains.

As a communicable disease, H1N1 swine flu influenza post doubles the disease burden in developing countries due to their vulnerability of the low socioeconomic strata, especially amongst the pregnant women. During pregnancy, the physiological and immunological changes such as a decrease in the tidal volume and lung capacity, increased oxygen consumption and cardiac output along with selective suppression of T-helper cell-mediated immunity which impairs maternal response to infection make them more prone to infections and its complications. The first reported case of influenza A virus of swine was in 2009 in Mexico.[8] In India, where disease-specific laboratorial test is still not widely available, the worst ever epidemic was faced in the year 2015 with >33,000 laboratory-confirmed cases and death of >2,000 people,[9] when compared to 5044 cases and 405 deaths in 2012[10] and 5250 cases and 692 deaths in 2013.[11] The states of Gujarat and Rajasthan were the worst affected followed by Delhi and Tamil Nadu, although the later states had lesser death toll due to awareness and a better developed healthcare sector.[12]

The percentage of positive samples in this present study was comparable to studies conducted by Mehta et al.[13] which showed 5.2% positivity, conducted in the year 2013. The virus is said to resurgent during the winter months because of the low ambient temperature and the ability of the viral particle to survive longer in cold temperatures which is the possible reason for the peak incidence of infection from November to January in the study.[14]

The most common presenting complaint was fever, followed by cough, rhinorrhoea and breathlessness which was similar to those in other Indian studies by Samra et al.,[15] Puvanalingam et al.[16] and Lim in their research, conducted in Singapore, demonstrated the risk of acquiring the infection and the need for hospitalisation increases by 1.2 fold in second trimester and 2.3 higher risk in third trimester which was in par with the finding of the present study.[17]

Studies have established that delayed initiation of antiviral treatment and the presence of underlying comorbidities are strongly associated with poor outcome of the patient which justified in this present study. Although in this study, hypothyroid is the most common co-existing medical illness; in literature, diabetes mellitus is the most common co-existing medical condition, followed by chronic renal failure, stroke, seizure and asthmatic.[15]

In the indexed study, the cause of morbidity was respiratory failure secondary to pneumonia and that cohort was an asthmatic with late presentation to the hospital and thereby delayed initiation of antiviral therapy. Maternal mortality rates recorded in the Indian studies vary widely from 3.7% to 70% compared to the reports from other countries probably due to the lack of awareness, poor diagnostic and intensive care management.

The mainstay goals in the prevention and treatment of H1N1 influenza infection involve isolation of the patient, universal precautions, infection control practices, early initiation of antiviral drugs, support care, vaccination, public awareness and education.[14] Herd immunity through vaccination should be strongly supported to all high-risk group, especially pregnant mothers to constrain further waves of pandemic.

  Conclusion Top

High preference should be given to antenatal mothers with H1N1 influenza. The mainstay goals in the prevention and treatment of H1N1 influenza infection should involve the isolation of the patient, universal precautions, infection control practices, early initiation of antiviral drugs, support care, vaccination, public awareness and education. Herd immunity through vaccination should be strongly supported to all high-risk groups, especially pregnant mothers to constrain further waves of pandemic. The limitations of this study are that it lacks comparison between the pregnant women testing positive and the non-pregnant women of the same age group testing positive at the same institution during the study period. This would have helped to assess the effect of infection on the course of disease and the outcome in the pregnant patients as against those who were not pregnant. In the absence of these comparisons, the study is just an observational study, and no further conclusions can be drawn from it other than its clinical correlations mentioned.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Biswas DK, Kaur P, Murhekar M, Bhunia R. An outbreak of pandemic influenza A (H1N1) in Kolkata, West Bengal, India, 2010. Indian J Med Res 2012;135:529-33.  Back to cited text no. 1
  [Full text]  
Neuzil KM, Reed GW, Mitchel EF, Simonsen L, Griffin MR. Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women. Am J Epidemiol 1998;148:1094-102.  Back to cited text no. 2
Griffith GW, Adelstein AM, Lambert PM, Weatherall JA. Influenza and infant mortality. Br Med J 1972;3:553-6.  Back to cited text no. 3
Nishiura H. Excess risk of stillbirth during the 1918-1920 influenza pandemic in Japan. Eur J Obstet Gynecol Reprod Biol 2009;147:115.  Back to cited text no. 4
Laibl VR, Sheffield JS. Influenza and pneumonia in pregnancy. Clin Perinatol 2005;32:727-38.  Back to cited text no. 5
Acs N, Bánhidy F, Puhó E, Czeizel AE. Maternal influenza during pregnancy and risk of congenital abnormalities in offspring. Birth Defects Res A Clin Mol Teratol 2005;73:989-96.  Back to cited text no. 6
Figueiró-Filho EA, Oliveira ML, Pompilio MA, Uehara SN, Coelho LR, De Souza BA, et al. Obstetric, clinical, and perinatal implications of H1N1 viral infection during pregnancy. Int J Gynaecol Obstet 2012;116:214-8.  Back to cited text no. 7
Centers for Disease Control and Prevention (CDC). Outbreak of swine-origin influenza A (H1N1) virus infection – Mexico, March-April 2009. MMWR Morb Mortal Wkly Rep 2009;58:467-70.  Back to cited text no. 8
Swine Flu Outbreak: 743 Deaths, 12,000 Cases set Alarm Bells Ringing. Hindustan Times; 21 February, 2015. Available form: http://www.hindustantimes.com/india/swine-flu-outbreak-774-deaths-13-000-cases-set-alarm-bells-ringing/story-qKeRWZ9QocPLll3Oif09RL.html. [Last retrieved on 2015 Feb 21].  Back to cited text no. 9
Cases of Influenza A H1N1 (Swine Flu) – State/UT-wise, Year-wise for 2009, 2010, 2011 and 2012.  Back to cited text no. 10
Laboratory confirmed Cases and Deaths caused by Pandemic Influenza A H1N1: State/ UT-wise. 1st January, 2013 – 22nd December, 2013. Available from: https://mohfw.gov.in/sites/default/files/7987622361. Pdf. [Last accessed on 2018 Jan 06].  Back to cited text no. 11
Swine Flu Death Toll Nears 600 in India. The Times of India. 18 February, 2015. [Last accessed on 2018 Jan 06].  Back to cited text no. 12
Mehta AA, Kumar VA, Nair SG, K Joseph Fs, Kumar G, Singh SK, et al. Clinical profile of patients admitted with swine-origin influenza A (H1N1) virus infection: An experience from A tertiary care hospital. J Clin Diagn Res 2013;7:2227-30.  Back to cited text no. 13
Mishra B. 2015 resurgence of influenza A (H1N1) 09: Smoldering pandemic in India? J Glob Infect Dis 2015;7:56-9.  Back to cited text no. 14
Samra T, Pawar M, Yadav A. One year of experience with H1N1 infection: Clinical observations from a tertiary care hospital in Northern India. Indian J Community Med 2011;36:241-3.  Back to cited text no. 15
[PUBMED]  [Full text]  
Puvanalingam A, Rajendiran C, Sivasubramanian K, Ragunanthanan S, Suresh S, Gopalakrishnan S, et al. Case series study of the clinical profile of H1N1 swine flu influenza. J Assoc Physicians India 2011;59:14-6, 18.  Back to cited text no. 16
Lim ML. 2009/H1N1 infection in pregnancy association with adverse perinatal outcomes. Evid Based Nurs 2012;15:11-2.  Back to cited text no. 17


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Materials and Me...

 Article Access Statistics
    PDF Downloaded12    
    Comments [Add]    

Recommend this journal