Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to pre... more Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor is very inaccurate. We used frequency-domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during regular pregnancies. Optical properties of uterine cervices were measured in 13 patients at various time points of regular pregnancies. For each gestational trimester, mean values with 95% confidence intervals were calculated for oxy-, deoxy-, and total hemoglobin concentration (O(2)Hb, HHb, tHb), tissue oxygen saturation and water content and statistically significant differences between the trimesters were determined. The wavelength-dependent scattering (scatter power) was calculated by an exponential fit. O(2)Hb, and tHb and the scatter power showed an increase as a function of the gestational age. Differences between the second and the third trimester were statistically significant. HHb and the water content showed no significant change over time. Our results show that FD-NIRS is a promising diagnostic tool for providing information about cervical content of hemoglobin, water, and extracellular matrix proteins. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
Objective: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripe... more Objective: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor has a substantial inter-and intraobserver variability. We used frequency domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during druginduced cervical ripening. Methods: Ten volunteers scheduled for abortion were examined. Optical properties of the uterine cervix were measured and physiological parameters were calculated prior to and after induction of cervical ripening using topical misoprostol. Mean relative changes, standard error of the mean as well as statistical significance using the t-test were calculated for oxy-and deoxyhemoglobin, total hemoglobin, oxygen-saturation, and water. The wavelength-dependent decrease of scattering (scatter power) was calculated by an exponential fit and tested with the Wilcoxon test. Results: Misoprostol induced a decrease in total hemoglobin of 21+/-6% (P<0.05), a decrease in oxyhemoglobin of 22+/-6% (P<0.05), a decrease in deoxyhemoglobin of 16+/-11% and an increase of 368% (P<0.005) in water content. The scatter power was significantly lower (P<0.05) after cervical ripening. Conclusion: Our results show that FD-NIRS is a promising diagnostic tool to detect changes in cervical concentrations of hemoglobin and water. A severe tissue edema, probably due to a hormone-induced inflammatory process, seems to be important for cervical ripening. The reduction in total hemoglobin is likely to be a consequence of the increased water content of the tissue resulting in a dramatic increase of the distance between vessels. We propose this technology to assess the cervical ripening and eventually to predict preterm labor. Lasers Surg. Med. 39:641-646, 2007.
Zusammenfassung. Impfungen vor und während der Schwangerschaft kommt eine wichtige Bedeutung zu. ... more Zusammenfassung. Impfungen vor und während der Schwangerschaft kommt eine wichtige Bedeutung zu. Viele Probleme könnten bei konsequenter Impfstrategie verhindert werden. Zwei Impfungen werden zurzeit routinemässig in jeder Schwangerschaft empfohlen. Einerseits die saisonale Grippeimpfung, die vor allem die Mutter vor der Influenza-Infektion während der Schwangerschaft schützen soll, da Schwangere häufiger schwere Verläufe oder Komplikationen aufweisen, und andererseits die Pertussisimpfung, die dem Neugeborenen in den ersten Lebenswochen nachweislich einen Schutz gibt.
ZusammenfassungNach welchen Infekten in der Schwangerschaft systematisch gesucht werden soll, hän... more ZusammenfassungNach welchen Infekten in der Schwangerschaft systematisch gesucht werden soll, hängt davon ab, ob die Voraussetzungen für ein Screening erfüllt sind. Dies ist der Fall etwa bei Röteln und Windpocken. Ideal wäre präkonzeptionelle Überprüfung des Impfstatus, ansonsten muss er in der Frühschwangerschaft überprüft werden, um die Mutter postpartal impfen zu können. Syphilis ist zwar selten, stellt aber ein ernsthaftes Problem dar bei einer Frühform in der Schwangerschaft und es gibt eine wirksame Therapie. Das HIV(humanes Immundefizienzvirus)-Screening in der Schwangerschaft hat sich flächendeckend etabliert. Die Kolonisation mit B‑Streptokokken ist bei subpartaler Übertragung hauptverantwortlich für die neonatale Sepsis, daher ist ein Screening sinnvoll. Andere Infektionen erfüllen die Kriterien für eine systematische Suche nicht, so etwa die Toxoplasmose oder eine Primärinfektion mit dem Cytomegalievirus in der Schwangerschaft.
Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to pre... more Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor is very inaccurate. We used frequency-domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during regular pregnancies. Optical properties of uterine cervices were measured in 13 patients at various time points of regular pregnancies. For each gestational trimester, mean values with 95% confidence intervals were calculated for oxy-, deoxy-, and total hemoglobin concentration (O(2)Hb, HHb, tHb), tissue oxygen saturation and water content and statistically significant differences between the trimesters were determined. The wavelength-dependent scattering (scatter power) was calculated by an exponential fit. O(2)Hb, and tHb and the scatter power showed an increase as a function of the gestational age. Differences between the second and the third trimester were statistically significant. HHb and the water content showed no significant change over time. Our results show that FD-NIRS is a promising diagnostic tool for providing information about cervical content of hemoglobin, water, and extracellular matrix proteins. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
Mastodynia is correlated with the menstrual cycle. Using frequency-domain near-infrared spectrosc... more Mastodynia is correlated with the menstrual cycle. Using frequency-domain near-infrared spectroscopy (FD-NIRS), we investigated changes in breast perfusion in women who were or were not using hormonal contraception. Healthy volunteers, on or not on hormonal contraception, were examined. Optical properties were measured in all quadrants of both breasts, and physiological parameters were calculated. Measurements were repeated every other day during one complete menstrual cycle. Measurements were comparable in all quadrants. Data remained unchanged during the entire cycle in patients using hormonal contraception. However, a biphasic variation of deoxyhemoglobin, oxyhemoglobin, total hemoglobin (tHb), and water content (H(2)O) was observed in women not using contraception. tHb and H(2)O distinctly increased during the ovulation period and remained elevated throughout the luteal phase. It was concluded that FD-NIRS allows accurate measurement of optical properties of human breasts. As opposed to the menstrual cycles of persons using oral contraception, spontaneous menstrual cycles exhibit biphasic variations of tissue perfusion parameters. These findings are important for the investigation of mastodynia.
Objective: To study the transfer of parenteral iron sucrose into maternal milk in the postpartum ... more Objective: To study the transfer of parenteral iron sucrose into maternal milk in the postpartum period. Study design: Ten healthy lactating mothers with functional iron deficiency 2-3days after delivery received 100mg intravenous iron sucrose and were observed together with a control group (n=5) without iron treatment during four days. Milk samples were taken before the treatment and every day afterwards. Results: Mean milk iron levels at baseline were 0.43 and 0.46mg/kg in the treatment and control group and decreased until the end of observation in both groups by 0.11mg/kg. No significant difference between the groups was found on any study day as well as in the mean change from baseline over all four days. Conclusion: We could not show transfer of iron-sucorose into maternal milk for the given dosage. Since parenteral iron sucrose is widely used in obstetrics, the results provide information about safety of parenteral iron sucrose in the lactation period. The findings are also in agreement with other reports on active biological mammary gland regulation of milk iron concentration
Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to pre... more Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor is very inaccurate. We used frequency-domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during regular pregnancies. Optical properties of uterine cervices were measured in 13 patients at various time points of regular pregnancies. For each gestational trimester, mean values with 95% confidence intervals were calculated for oxy-, deoxy-, and total hemoglobin concentration (O(2)Hb, HHb, tHb), tissue oxygen saturation and water content and statistically significant differences between the trimesters were determined. The wavelength-dependent scattering (scatter power) was calculated by an exponential fit. O(2)Hb, and tHb and the scatter power showed an increase as a function of the gestational age. Differences between the second and the third trimester were statistically significant. HHb and the water content showed no significant change over time. Our results show that FD-NIRS is a promising diagnostic tool for providing information about cervical content of hemoglobin, water, and extracellular matrix proteins. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
Objective: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripe... more Objective: Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor has a substantial inter-and intraobserver variability. We used frequency domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during druginduced cervical ripening. Methods: Ten volunteers scheduled for abortion were examined. Optical properties of the uterine cervix were measured and physiological parameters were calculated prior to and after induction of cervical ripening using topical misoprostol. Mean relative changes, standard error of the mean as well as statistical significance using the t-test were calculated for oxy-and deoxyhemoglobin, total hemoglobin, oxygen-saturation, and water. The wavelength-dependent decrease of scattering (scatter power) was calculated by an exponential fit and tested with the Wilcoxon test. Results: Misoprostol induced a decrease in total hemoglobin of 21+/-6% (P<0.05), a decrease in oxyhemoglobin of 22+/-6% (P<0.05), a decrease in deoxyhemoglobin of 16+/-11% and an increase of 368% (P<0.005) in water content. The scatter power was significantly lower (P<0.05) after cervical ripening. Conclusion: Our results show that FD-NIRS is a promising diagnostic tool to detect changes in cervical concentrations of hemoglobin and water. A severe tissue edema, probably due to a hormone-induced inflammatory process, seems to be important for cervical ripening. The reduction in total hemoglobin is likely to be a consequence of the increased water content of the tissue resulting in a dramatic increase of the distance between vessels. We propose this technology to assess the cervical ripening and eventually to predict preterm labor. Lasers Surg. Med. 39:641-646, 2007.
Zusammenfassung. Impfungen vor und während der Schwangerschaft kommt eine wichtige Bedeutung zu. ... more Zusammenfassung. Impfungen vor und während der Schwangerschaft kommt eine wichtige Bedeutung zu. Viele Probleme könnten bei konsequenter Impfstrategie verhindert werden. Zwei Impfungen werden zurzeit routinemässig in jeder Schwangerschaft empfohlen. Einerseits die saisonale Grippeimpfung, die vor allem die Mutter vor der Influenza-Infektion während der Schwangerschaft schützen soll, da Schwangere häufiger schwere Verläufe oder Komplikationen aufweisen, und andererseits die Pertussisimpfung, die dem Neugeborenen in den ersten Lebenswochen nachweislich einen Schutz gibt.
ZusammenfassungNach welchen Infekten in der Schwangerschaft systematisch gesucht werden soll, hän... more ZusammenfassungNach welchen Infekten in der Schwangerschaft systematisch gesucht werden soll, hängt davon ab, ob die Voraussetzungen für ein Screening erfüllt sind. Dies ist der Fall etwa bei Röteln und Windpocken. Ideal wäre präkonzeptionelle Überprüfung des Impfstatus, ansonsten muss er in der Frühschwangerschaft überprüft werden, um die Mutter postpartal impfen zu können. Syphilis ist zwar selten, stellt aber ein ernsthaftes Problem dar bei einer Frühform in der Schwangerschaft und es gibt eine wirksame Therapie. Das HIV(humanes Immundefizienzvirus)-Screening in der Schwangerschaft hat sich flächendeckend etabliert. Die Kolonisation mit B‑Streptokokken ist bei subpartaler Übertragung hauptverantwortlich für die neonatale Sepsis, daher ist ein Screening sinnvoll. Andere Infektionen erfüllen die Kriterien für eine systematische Suche nicht, so etwa die Toxoplasmose oder eine Primärinfektion mit dem Cytomegalievirus in der Schwangerschaft.
Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to pre... more Preterm labor is a common obstetric complication. Clinical evaluation of cervical ripening to predict preterm labor is very inaccurate. We used frequency-domain near-infrared spectroscopy (FD-NIRS) to non-invasively investigate the changes of the optical properties (i.e., absorption and scattering of light) in the uterine cervix during regular pregnancies. Optical properties of uterine cervices were measured in 13 patients at various time points of regular pregnancies. For each gestational trimester, mean values with 95% confidence intervals were calculated for oxy-, deoxy-, and total hemoglobin concentration (O(2)Hb, HHb, tHb), tissue oxygen saturation and water content and statistically significant differences between the trimesters were determined. The wavelength-dependent scattering (scatter power) was calculated by an exponential fit. O(2)Hb, and tHb and the scatter power showed an increase as a function of the gestational age. Differences between the second and the third trimester were statistically significant. HHb and the water content showed no significant change over time. Our results show that FD-NIRS is a promising diagnostic tool for providing information about cervical content of hemoglobin, water, and extracellular matrix proteins. We propose this technology to assess the cervical ripening and eventually to predict preterm labor.
Mastodynia is correlated with the menstrual cycle. Using frequency-domain near-infrared spectrosc... more Mastodynia is correlated with the menstrual cycle. Using frequency-domain near-infrared spectroscopy (FD-NIRS), we investigated changes in breast perfusion in women who were or were not using hormonal contraception. Healthy volunteers, on or not on hormonal contraception, were examined. Optical properties were measured in all quadrants of both breasts, and physiological parameters were calculated. Measurements were repeated every other day during one complete menstrual cycle. Measurements were comparable in all quadrants. Data remained unchanged during the entire cycle in patients using hormonal contraception. However, a biphasic variation of deoxyhemoglobin, oxyhemoglobin, total hemoglobin (tHb), and water content (H(2)O) was observed in women not using contraception. tHb and H(2)O distinctly increased during the ovulation period and remained elevated throughout the luteal phase. It was concluded that FD-NIRS allows accurate measurement of optical properties of human breasts. As opposed to the menstrual cycles of persons using oral contraception, spontaneous menstrual cycles exhibit biphasic variations of tissue perfusion parameters. These findings are important for the investigation of mastodynia.
Objective: To study the transfer of parenteral iron sucrose into maternal milk in the postpartum ... more Objective: To study the transfer of parenteral iron sucrose into maternal milk in the postpartum period. Study design: Ten healthy lactating mothers with functional iron deficiency 2-3days after delivery received 100mg intravenous iron sucrose and were observed together with a control group (n=5) without iron treatment during four days. Milk samples were taken before the treatment and every day afterwards. Results: Mean milk iron levels at baseline were 0.43 and 0.46mg/kg in the treatment and control group and decreased until the end of observation in both groups by 0.11mg/kg. No significant difference between the groups was found on any study day as well as in the mean change from baseline over all four days. Conclusion: We could not show transfer of iron-sucorose into maternal milk for the given dosage. Since parenteral iron sucrose is widely used in obstetrics, the results provide information about safety of parenteral iron sucrose in the lactation period. The findings are also in agreement with other reports on active biological mammary gland regulation of milk iron concentration
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Papers by Michele Stahel