736 - NON INVASIVE CARBON MONOXIDE (SpCO) VALUES IN THE PERINATAL PERIOD

Poster Number: 736
Publication Number: 736.245

Maria V. Favareto, Iberoamerican Society of Neonatology, SIBEN, Rosario, Santa Fe, Argentina; Monica Menzio, SIBEN, San Luis, San Luis, Argentina; Ignacio A. Sosa, clinica universitara Reina Fabiola, Cordoba, Cordoba, Argentina; Marcelo Cardetti, Sociedad Iberoamericana de Neonatología, San Luis, San Luis, Argentina; Susana Rodriguez, SIBEN, CABA, Buenos Aires, Argentina; Augusto Sola, Ibero American Society of Neonatology-, Wellington, FL, United States

Background: Carbon monoxide (CO) is a poisonous and lethal gas. Exposure to CO raises levels of carboxyhemoglobin (COHb) which reduces the oxygen (O2 ) carrying capacity and shift the Hb dissociation curve to the left, diminishing the release of O2 to the tissues generating hypoxia. There is scant data on SpCO in the perinatal period and it is now possible to measure CO in a noninvasive and continuous way.

Objective: Describe CO values measured non-invasively with pulse oximetry (SpCO) in healthy term mothers and newborns in the peripartum
period.

Design/Methods: Multicenter descriptive study in four maternities in Argentina. After ethics review and parental informed consent, SpCO and simultaneous SpO2 were measured at ≤ 3 hours and at 24 hours after birth in healthy term mothers and their newborns with Masimo SET Rad-57 ® multiwavelength pulse Co-oximeter (Masimo Co, Irvine, USA). We prospectively
collected demographic data, previous history of maternal smoking, smoking during pregnancy and environmental pollution risk factors. SpCO > 3% was considered elevated. RedCap data base and software statistics STATA16.0 were used to present descriptive statistics and parametric and non-parametric associations.

Results: 452 healthy mothers and term newborns were evaluated (March-August 2022). Maternal age: 28 ± 6 years; 178 (39%) were previous smokers and 51 (11%) referred smoking during pregnancy. For home heating, 38% used gas stove. The interviewers detected risk of environmental pollution in 8% (n 36). Newborns’ birth weight: 3,349 ± 442 g; none of them had hemolysis or required NICU admission. In the first measurement, mean maternal SpCO was 3.21 ± 2.8%; 158 mothers (35%) had a high SpCO
level ( > 3%). In the second one, maternal SpCO was 2.79±2,5% and 21 (13%) had SpCO > 3%. High SpCO did not correlate with maternal history of smoking, but 22 (43%) of 51 mothers who smoked during pregnancy had high SpCO. In the two neonatal determinations, SpCO were 0.94 ± 1.7% and 0.73 ± 1.4% respectively, significantly lower than maternal SpCO (- 2.27%
IC95% -1.96 a -2.57). SpCO > 3% occurred in 34 (7.5%) of the newborns, mostly related to high maternal SpCO. We found no relationship between high SpCO and lower SpO2 levels; SpO2 was ≥ 95% in all cases.

Conclusion(s): In this first description of perinatal noninvasive SpCO in healthy mothers and their term newborns, neonatal SpCO was lower than maternal and a few newborns had elevated SpCO without low SpO₂.These findings will be useful for future research to assess the potential impact of elevated perinatal SpCO in populations at risk.
Acknowledgement: Research grant from SIBEN.