title: Maternal hyperventilation during labor revisited: its effects on fetal oxygenation.
abstract: To investigate the relationship between maternal hyperventilation and fetal blood gas values and to estimate its possible association with fetal oxygenation, maternal transcutaneous partial pressure of carbon dioxide (tcP(CO2)) values were analyzed in association with umbilical venous P(CO2) (UVP(CO2)), umbilical venous partial pressure of oxygen (UVP(O2)), and umbilical venous oxyhemoglobin saturation (UVHbo (2)) values. Pregnant women without labor (30.7 ± 3.7 mm Hg, n = 20) showed significantly lower tcP(CO2) values compared with nonpregnant women (37.4 ± 4.0 mm Hg, n = 10). Pregnant women in the second stage of labor showed even lower tcP(CO2) values compared with pregnant women during the first stage of labor (20.8 ± 5.9 mm Hg vs 28.4 ± 5.0 mm Hg, n = 26). Maternal tcP(CO2) values had significant positive correlations with UVP(CO2) (r = .78, P < .001), UVP(O2) (r = .62, P < .001), and UVHb(O2) values (r = .59, P < .001). Maternal hyperventilation had a close relationship with lower UVP(CO2), UVP(O2), and UVHbo(2) values, which might interfere with optimal fetal cerebral oxygenation.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan. tomimatsu@gyne.med.osaka-u.ac.jp
authors.forename: Takuji
authors.initials: T
authors.lastname: Tomimatsu
authors.forename: Aiko
authors.initials: A
authors.lastname: Kakigano
authors.forename: Kazuya
authors.initials: K
authors.lastname: Mimura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kanayama
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Koyama
authors.forename: Satoko
authors.initials: S
authors.lastname: Fujita
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Taniguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanagawa
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kimura
mesh_terms: D000328:Adult; D001034:Apgar Score; D001724:Birth Weight; D001921:Brain / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005865:Gestational Age; D006801:Humans; D006985:Hyperventilation / Q000150:complications* / Q000503:physiopathology; D007231:Infant, Newborn; D007744:Obstetric Labor Complications / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood* / Q000378:metabolism; D010108:Oxyhemoglobins / Q000032:analysis; D010313:Partial Pressure; D011247:Pregnancy; D014471:Umbilical Veins
chemical_list: D010108:Oxyhemoglobins; D002245:Carbon Dioxide; D010100:Oxygen