New approaches on fetal and maternal intrapartum monitoring
Author: Wretler, Stina
Date: 2017-06-09
Location: Skandiasalen, Q3:01, Karolinska University Hospital, Solna
Time: 09:00
Department: Inst för kvinnors och barns hälsa / Dept of Women's and Children's Health
View/ Open:
Thesis (1.411Mb)
Abstract
Background: Intrapartum fetal monitoring aims to prevent adverse outcomes due to intrapartum asphyxia. Cardiotocography (CTG) is an established method for intrapartum monitoring. The method has high sensitivity, but low specificity and is also user-dependent and linked to both inter- and intraobserver variability. CTG might increase the risk for unnecessary interventions. One suggested method to improve CTG interpretation is computerized monitoring. Other possible ways are improved knowledge about risk factors and proper use of adjunctive technologies. One common adjunctive technology is fetal scalp blood sampling (FBS). Fetal distress is one reason for intrapartum caesarean section, but the main reason is dystocia. Today there is no way to predict dystocia. Studies have suggested that increased levels of lactate in the uterus correlates with dystocia.
Materials and Methods: Study 1 is a prospective observational study of 120 women, investigating methodological aspects of short-term-variation (STV) as a part of computerized fetal monitoring. Paper 2 and 3 study 1070 term pregnancies that underwent FBS. Study 2 is an analysis of lactacidemia in FBS compared to different CTG patterns. Study 3 is an analysis of risk factors for lactacidemia in FBS. Study 4 is a clinical observational study, of 77 women in labor, evaluating if lactate concentration in cervical fluid could be a predictor for dystocia.
Results: STV values differ between internal and external derived values. The two commercial available CTG machines for antenatal STV monitoring perform equal. Late or severe variable decelerations in combination with tachycardia are the CTG patterns with highest frequency of lactacidemia. Isolated reduced variability in an otherwise normal CTG trace is not linked to lactacidemia. Risk factors correlated to lactacidemia are minor language barriers and active bearing down. Increased concentration of lactate in cervical fluid seems to predict operative delivery.
Conclusions: These results suggest several implications on intrapartum monitoring. Intrapartum STV values should preferably be derived from internal monitoring. The same cut-off values could be used for the two commercial available machines for STV monitoring. Late and severe variable decelerations correlate to lactacidemia to the same extent. Isolated reduced variability is not a sign of hypoxia. Use of interpreters can be a possible way to avoid adverse neonatal outcome. Cervical lactate might be a possible tool in predicting dystocia.
Materials and Methods: Study 1 is a prospective observational study of 120 women, investigating methodological aspects of short-term-variation (STV) as a part of computerized fetal monitoring. Paper 2 and 3 study 1070 term pregnancies that underwent FBS. Study 2 is an analysis of lactacidemia in FBS compared to different CTG patterns. Study 3 is an analysis of risk factors for lactacidemia in FBS. Study 4 is a clinical observational study, of 77 women in labor, evaluating if lactate concentration in cervical fluid could be a predictor for dystocia.
Results: STV values differ between internal and external derived values. The two commercial available CTG machines for antenatal STV monitoring perform equal. Late or severe variable decelerations in combination with tachycardia are the CTG patterns with highest frequency of lactacidemia. Isolated reduced variability in an otherwise normal CTG trace is not linked to lactacidemia. Risk factors correlated to lactacidemia are minor language barriers and active bearing down. Increased concentration of lactate in cervical fluid seems to predict operative delivery.
Conclusions: These results suggest several implications on intrapartum monitoring. Intrapartum STV values should preferably be derived from internal monitoring. The same cut-off values could be used for the two commercial available machines for STV monitoring. Late and severe variable decelerations correlate to lactacidemia to the same extent. Isolated reduced variability is not a sign of hypoxia. Use of interpreters can be a possible way to avoid adverse neonatal outcome. Cervical lactate might be a possible tool in predicting dystocia.
List of papers:
I. Fetal heart rate monitoring of short term variation (STV): a methodological observational study. Stina Wretler, Malin Holzmann, Sophie Graner, Pelle Lindqvist, Susanne Falck and Lennart Nordström. BMC Pregnancy and Childbirth Published online: 2016 March 16.
Fulltext (DOI)
Pubmed
View record in Web of Science®
II. Cardiotocography patterns and risk of intrapartum fetal acidemia. Malin Holzmann, Stina Wretler, Sven Cnattingius and Lennart Nordström. Journal of Perinatal Medicine 2015 Jul;43(4):473-9.
Fulltext (DOI)
Pubmed
View record in Web of Science®
III. Risk factors for intrapartum acidemia – a cohort study. Stina Wretler, Lennart Nordström, Sophie Graner and Malin Holzmann. [Submitted]
IV. Intrapartum cervical lactate as a predictor of operative delivery: An observational clinical study. Stina Wretler, Sophie Graner, Malin Holzmann and Lennart Nordström. [Submitted]
I. Fetal heart rate monitoring of short term variation (STV): a methodological observational study. Stina Wretler, Malin Holzmann, Sophie Graner, Pelle Lindqvist, Susanne Falck and Lennart Nordström. BMC Pregnancy and Childbirth Published online: 2016 March 16.
Fulltext (DOI)
Pubmed
View record in Web of Science®
II. Cardiotocography patterns and risk of intrapartum fetal acidemia. Malin Holzmann, Stina Wretler, Sven Cnattingius and Lennart Nordström. Journal of Perinatal Medicine 2015 Jul;43(4):473-9.
Fulltext (DOI)
Pubmed
View record in Web of Science®
III. Risk factors for intrapartum acidemia – a cohort study. Stina Wretler, Lennart Nordström, Sophie Graner and Malin Holzmann. [Submitted]
IV. Intrapartum cervical lactate as a predictor of operative delivery: An observational clinical study. Stina Wretler, Sophie Graner, Malin Holzmann and Lennart Nordström. [Submitted]
Institution: Karolinska Institutet
Supervisor: Nordström, Lennart
Co-supervisor: Graner, Sophie; Holzmann, Malin
Issue date: 2017-05-18
Rights:
Publication year: 2017
ISBN: 978-91-7676-592-0
Statistics
Total Visits
Views | |
---|---|
New ...(legacy) | 719 |
New ... | 437 |
Total Visits Per Month
September 2023 | October 2023 | November 2023 | December 2023 | January 2024 | February 2024 | March 2024 | |
---|---|---|---|---|---|---|---|
New ... | 0 | 2 | 0 | 0 | 0 | 2 | 0 |
File Visits
Views | |
---|---|
Thesis_Stina_Wretler.pdf | 1333 |
Thesis_Stina_Wretler.pdf(legacy) | 1035 |
Top country views
Views | |
---|---|
Sweden | 230 |
United States | 184 |
Denmark | 117 |
Germany | 63 |
China | 40 |
South Korea | 26 |
United Kingdom | 23 |
Australia | 17 |
Austria | 16 |
India | 16 |
Top cities views
Views | |
---|---|
Ashburn | 79 |
Copenhagen | 55 |
Stockholm | 24 |
Seoul | 19 |
Vienna | 16 |
Woodbridge | 15 |
Beijing | 14 |
Kiez | 12 |
Houston | 11 |
Ballerup | 10 |