Expired Air Carbon Monoxide Levels as a Marker of Passive Smoking In Pregnant Women


  • Amareswari V.H.1 , Padma K.2




Expired air carbon monoxide, pregnant women, passive smokers, foetal carboxy haemoglobin.


Background and Aim: Smoking directly or indirectly has serious impact on health of an individual.

During smoking various chemicals and toxic substances are released into the air such as nicotine, carbon

monoxide which can be inhaled by the people nearby indirectly. Pregnant mothers may passively inhale

carbonmonoxidewhen exposed to such environment. Maternal Carbon monoxide passes through placenta

and enters foetalblood combine with foetalhaemoglobin forming foetal carboxy haemoglobin. Foetal carboxy

haemoglobin in turn makes oxygen unavailableto foetal tissues which could be the reason for various poor

outcomes in unborn foetus such as low birth weight, intra uterine growth retardation with higher rates of

perinatal mortality. This study is aimed at measuring the expired air carbon monoxide levels in passively

smoking pregnant women that can be correlated with exposure to passive smoking.

Method and Materials: 100 antenatal women of gestational age between 26 to 34 weeks with and without

exposure to passive smoking were measured for carbon monoxide levels in their expired air usingsimple,

portable non invasive carbon monoxidemonitor.

Statistical Analysis: Data analysis was done with unpaired student t test. P value of <0.05 was taken to be


Results: No significant statistical difference is observed between cases and control groupsin expired

aircarbon monoxide levels.

Discussion and Conclusion: The lesser half life of carbon monoxide in exhaled air. The longtime interval

between the exposure and the time of testing, the metabolic changes associated with pregnancy could have

made this test inconclusive. Though gold standard blood analytic method cannot be replaced by this breath

monitors,it can be used as a simple portable noninvasive toolto educate pregnant women to avoid exposure

to passive smoking.

Author Biography

Amareswari V.H.1 , Padma K.2

1Assistant Professor, Dept of Physiology, Rajarajeswari Medical College, Bengaluru, 2Redt Prof and Director, Dept of Physiology, Madras Medical College, Chennai, Tamilnadu



How to Cite

Amareswari V.H.1 , Padma K.2. (2020). Expired Air Carbon Monoxide Levels as a Marker of Passive Smoking In Pregnant Women. International Journal of Physiology, 8(3), 6-11. https://doi.org/10.37506/ijop.v8i3.1321