Uterine Activity[ edit ] There are several factors used in assessing uterine activity. Frequency- the amount of time between the start of one contraction to the start of the next contraction. Duration- the amount of time from the start of a contraction to the end of the same contraction. Intensity- a measure of how strong a contraction is. With external monitoring, this necessitates the use of palpation to determine relative strength. With an IUPC, this is determined by assessing actual pressures as graphed on the paper.
|Genre:||Health and Food|
|Published (Last):||12 June 2005|
|PDF File Size:||8.21 Mb|
|ePub File Size:||17.6 Mb|
|Price:||Free* [*Free Regsitration Required]|
Uterine Activity[ edit ] There are several factors used in assessing uterine activity. Frequency- the amount of time between the start of one contraction to the start of the next contraction. Duration- the amount of time from the start of a contraction to the end of the same contraction.
Intensity- a measure of how strong a contraction is. With external monitoring, this necessitates the use of palpation to determine relative strength. With an IUPC, this is determined by assessing actual pressures as graphed on the paper. Resting Tone- a measure of how relaxed the uterus is between contractions. With an IUPC, this is determined by assessing actual pressures as graphed on the paper Interval- the amount of time between the end of one contraction to the beginning of the next contraction.
The NICHD nomenclature  defines uterine activity by quantifying the number of contractions present in a minute window, averaged over 30 minutes. Uterine activity may be defined as: Normal- less than or equal to 5 contractions in 10 minutes, averaged over a minute window Tachysystole- more than 5 contractions in 10 minutes, averaged over a minute window Baseline fetal heart rate[ edit ] The NICHD nomenclature  defines baseline fetal heart rate as: The baseline FHR is determined by approximating the mean FHR rounded to increments of 5 beats per minute bpm during a minute window, excluding accelerations and decelerations and periods of marked FHR variability greater than 25 bpm.
There must be at least 2 minutes of identifiable baseline segments not necessarily contiguous in any minute window, or the baseline for that period is indeterminate. In such cases, it may be necessary to refer to the previous minute window for determination of the baseline.
Abnormal baseline is termed bradycardia when the baseline FHR is less than bpm; it is termed tachycardia when the baseline FHR is greater than bpm. Its presence is reassuring in predicting an absence of metabolic acidemia and hypoxic injury to the fetus at the time it is observed. Baseline FHR variability is defined as fluctuations in the baseline FHR that are irregular in amplitude and frequency.
The fluctuations are visually quantitated as the amplitude of the peak-to-trough in beats per minute. Using this definition, the baseline FHR variability is categorized by the quantitated amplitude as: Absent- undetectable Minimal- greater than undetectable, but less than or equal to 5 beats per minute Moderate- beats per minute Marked- greater than 25 beats per minute Saltatory pattern of fetal heart rate[ edit ] Saltatory pattern of fetal heart rate is defined in cardiotocography CTG guidelines by FIGO The International Federation of Gynaecology and Obstetrics and NICE The National Institute for Health and Care Excellence as fetal heart rate FHR baseline amplitude changes of more than 25 beats per minute bpm.
According to this study, saltatory pattern is relatively rare condition, thus only four cases were found from three large databases. In a recent study by Tarvonen et al. As saltatory patterns preceded late decelerations of fetal heart rate FHR in the majority of cases, saltatory pattern seems to be an early sign of fetal hypoxia.
An abrupt increase is defined as an increase from the onset of acceleration to the peak in less than or equal to 30 seconds. To be called an acceleration, the peak must be greater than or equal to 15 bpm, and the acceleration must last greater than or equal to 15 seconds from the onset to return to baseline. An acceleration lasting greater than or equal to 10 minutes is defined as a baseline change.
Before 32 weeks of gestation, accelerations are defined as having a peak greater than or equal to 10 bpm and a duration of greater than or equal to 10 seconds. There are four types of decelerations as defined by the NICHD nomenclature, all of which are visually assessed. Monitoring usually shows a symmetrical, gradual decrease and return to baseline of FHR which is associated with a uterine contraction.
Early decelerations begin and end at approximately the same time as contractions, and the low point of the fetal heart rate occurs at the peak of the contraction. Monitoring usually shows symmetrical gradual decrease and return to baseline of the fetal heart rate in association with a uterine contraction. In contrast to early deceleration, the low point of fetal heart rate occurs after the peak of the contraction, and returns to baseline after the contraction is complete.
They are defined as abrupt decreases in fetal heart rate, with less than 30 seconds from the beginning of the decrease to the nadir of heart rate. The decrease in FHR is greater than or equal to 15 beats per minute, lasting greater than or equal to 15 seconds, and less than 2 minutes in duration.
A deceleration greater than or equal to 10 minutes is a baseline change. The NICHD workgroup proposed terminology of a three-tiered system to replace the older, undefined terms.
Category II Indeterminate : Tracing is not predictive of abnormal fetal acid-base status, but evaluation and continued surveillance and reevaluations are indicated. No clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing, neither on any meaningful long-term outcomes could be shown. Continuous CTG was associated with the higher rates of caesarean sections and instrumental vaginal births.
The authors see the challenge in how to discuss these results with women to enable them to make an informed decision without compromising the normality of labour. Future research should focus on events that happen in pregnancy and labour that could be the cause of long-term problems for the baby.
Se nada for encontrado, uma amostra de sangue do escalpo fetal vai mostrar qual o grau de danos do feto. Se a posio for distocica ou no tem acesso direto ao escalpo fetal, a interrupo da gravidez tem que ser feita sem atraso. As deceleraoes variveis so classificadas como graves se durar mais de 60 segundos ou se for com menos de 90 bpm. Vantagens e desvantagens. Dentre todas a nica que no pode ser utilizada a longo prazo por exemplo durante o trabalho de parto e a visualizao ultrasonica direta. Pode ser estabelecido um ritmo normal, escutando com estetoscpio entre as contraes, depois escutar 30 segundos depois uma contrao.
Cardiotocografia – O que é, quando fazer?