How to Read a Fetal Monitor During Labor

You are most likely not in labor if the machine registers four or fewer contractions per hour. Your doctor conducts a cervical ultrasound or pelvic exam if your contractions are more frequent to confirm the diagnosis of preterm labor.

It might be challenging to tell the difference between contractions that are a normal part of pregnancy and those that might indicate the beginning of preterm labor.

Early studies suggested that home uterine activity monitoring (HUAM) could prevent early delivery, but more recent studies have shown that HUAM is not useful.

There, nurses analyze the information and write a thorough report about the contractions for your doctor. Nurses can also provide information on how to put on the band and take care of oneself.

According to some researchers, uterine monitoring may be beneficial in certain situations. If a woman has a history of cervical insufficiency and a fetal fibronectin test is positive, for instance, then increasing contractions on a home monitor may indicate that she is at risk of giving birth soon.

To examine variable distributions and summarize subject characteristics, descriptive statistics and graphical techniques were used. For each participant, performance metrics such as CCI, PPV (which equals true positives minus false positives), and sensitivity (which equals true positives minus false negatives) were calculated. Consistent contractions are considered true positives, while contractions found on the Toco/EHG curve but not the IUPC curve are considered false positives, and contractions found on the IUPC curve but not the Toco/EHG curve are considered false negatives. EHG and Toco means were compared using two-sided paired t-tests. In the same way as before, comparisons of the timing of contractions (peak, onset, offset, and duration) were also made. BMI and CCI, PPV, and sensitivity were examined in relation to one another using estimates of Pearson correlation coefficients. To compare obese women (BMI), we also used two-sided, two-sample t tests. 75, correlation, PPV, and sensitivity. A sample size of 59 provides adequate power (0 80) to detect a 0. 37 s. d. unit difference between means and a correlation of 0. 35 or larger. A p-value of less than 0. 05 was considered statistically significant. Analyses were performed using SAS (version 9. 1), and R (version 2. 12. 0).

Even in the non-obese, Toco suffers frequent failures. Bakker et al3 describe some period of %E2%80%9Cinadequate registration%E2%80%9D (no tracing or unreliable pattern due to inadequate calibration) in 98% of 41 labors, for an average of 35% of stage-one duration and 33% of stage-two They also report %E2%80%9Cinadequate registration%E2%80%9D in 60% of 151 patients monitored with IUPC, for 28% of stage one and 30% of stage two durations

A uterine activity channel from two maternal-fetal monitors (Corometrics, GE Medical Systems; Waukesha, Wisconsin, USA) sampled at 8 Hz with 8-bit resolution was included in the data for each patient. These cardiotocographs (CTG) reported the Toco- and IUPC-derived contraction curves. The output of four abdominal EHG channels, sampled at 500 Hz with 24-bit resolution, was also included in the data.

A 4-channel high-resolution, low-noise unipolar amplifier was fed the recorded signals. The measurements of all four signals were made in relation to a reference electrode. Driven right-leg (DRL) circuitry was used in the amplifier design to lessen common mode noise between the patient and the amplifier. The amplifier 3-dB bandwidth was 0. 05 to 250 Hz.

As was mentioned in the introduction, a number of research teams, including our own,14 have linked obesity to a higher risk of Toco monitoring failure. Obesity had an impact on CCI in the current study for both non-invasive technologies, but it had no effect on Toco. 60 in this subgroup, compared to 0. 82 for EHG (p=. 03). Similarly, % Time CCI<0. 75 increased to more than half the monitoring time (56. 0%) for Toco in obese parturients, but remained less than one-quarter (24 2%) for EHG (p=. 01). Due to their increased risk of labor complications, obese expectant mothers require extra attention. 17 Ray et al1 noted a 32% incidence of complications (postpartum hemorrhage, third degree tears and extension of episiotomy, and shoulder dystocia) in obese patients vs 6% in controls Obese patients experience longer labors and more cesarean deliveries even when there are no such complications. Obese parturients have a significantly higher risk of contracting an infection due to longer labor, which necessitates more cervical examinations, a high rate of induction/augmentation, and challenging non-invasive monitoring requiring the use of IUPC and/or fetal scalp electrode. 17 Once infected, abnormal uterine contractility lengthens labor even more and raises the risk of cesarean delivery. 20 In addition, chorioamnionitis raises the risk of uterine atony, maternal blood transfusion, pelvic abscess, septic pelvic thrombophlebitis, and a poor neonatal outcome. EHG monitoring for uterine activity may lessen these complications by eliminating the requirement for intrauterine monitoring, by providing accurate contraction data early in labor that may eliminate the requirement for repeated cervical examinations, and possibly by facilitating the safe titration of oxytocin.

The fetal scalp clip has 2 coloured wires attached. A matchbox-sized conducting device, used to connect the wires to the lead, is fastened to the woman’s thigh. A typical CTG reading is then printed on paper or saved to a computer for later use after the lead is plugged into the monitor. Continuous remote monitoring is made possible by the use of CTG and a computer network. A single nurse, midwife, or doctor can monitor the CTG traces of multiple patients at once using a computer station.

A tiny, corkscrew-shaped, circular needle with a coated wire attached to it is a fetal scalp electrode. The caregiver performing an internal examination guides the clip up through the mother’s vagina while it is protected by a lengthy, flexible, protective plastic covering. The baby’s scalp is gently probed with the needle as it rotates. The plastic cover is taken off after the clip is attached, exposing the wire.

A technical procedure known as cardiotocography (CTG) is used to record the fetal heartbeat and uterine contractions during pregnancy, usually in the third trimester. The monitoring device is referred to as a cardiotocograph, also called an electronic fetal monitor. CTG can be used to identify signs of fetal distress.

Cardiotocography (Fetal Monitors) | Part 1| Introduction | Biomedical Engineers TV

Leave a Comment