Internal fetal monitoring is accomplished with a fetal scalp electrode that is a direct electrocardiogram of the FHR and therefore produces the most accurate FHR tracing having an advantage over the external monitoring. The FSE is attached to the fetus during a vaginal exam and then connected to a fetal monitor. Because the risk of transmission to the fetus is increased by the small puncture in the fetal scalp, use of internal scalp electrodes should be avoided if at all possible in the presence of known maternal infections such as HIV, hepatitis or GBS. Fetal scalp monitors are also avoided in preterm infants because of the increased risk of ventricular hemorrhage.
Electronic monitoring of UCs can be done internally by using an intrauterine pressure catheter (IUPC). It is inserted into the uterine cavity through the cervical os. It reflects the pressure inside the uterine cavity. As the pressure changes, it traces on the graph paper. The IUPC can measure the resting tone of the uterus between contractions, referred to as intensity. An advantage of an IUPC is that it provides a near-exact pressure measurement for contraction intensity and uterine resting tone. The sensitivity of the IUPC allows for very accurate timing of UCs, thus making it extremely useful when closer uterine monitoring is needed. A disadvantage for both internal monitoring methods is that membranes must be ruptured and adequate cervical dilation must be achieved for insertion. The procedure is invasive and increases the risk of uterine infection or perforation or trauma. It can also cause a placenta rupture if the placenta is low-lying.
Electronic FHR monitoring can be done externally by using an ultrasound (US) transducer. The transducer is placed on the maternal abdomen over the fetal back and held by an elastic belt. The US transducer can be more beneficial than auscultating the FHR because it provides a continuous graphic recording. It can show the baseline variability and changes in the FHR. It is noninvasive and doesn’t require the rupture of membranes or minimal cervical dilation. FHR monitoring by US transducer is limited because it is susceptible to interference from maternal or fetal movement and may produce a weak signal. The tracing may become sketchy and difficult to interpret. Telemetry is another type external monitoring.
It can monitor both FHR and uterine activity. This system can be worn on a shoulder strap by the mother, which allows the woman to ambulate, helping her ambulate while continuously monitoring. Electric monitoring of UCs can be done externally using a tocodynamometer or tocotransducer (toco). The toco is placed on the maternal abdomen at or near the fundus and held in place by an elastic belt. As the uterus contracts, pressure exerted against the toco is transmitted and recorded on to graph paper. The toco can assess UCs for frequency and duration, but not intensity. The advantages are that it is non-invasive, easy to place, and may be used both before and following rupture of membranes. It also provides a permanent, continuous recording of the duration and frequency of contractions.
Explain what Pitocin is used for:
Pitocin is used for the induction and/or augmentation of labor at term, facilitation of threatened abortion, and in postpartum to control bleeding and prevent hemorrhage and uterine atony after expulsion of the placenta.
PELVIC ASSESSMENT FINDINGS:Give normal findings and measurements
Diagonal conjugate – extends from the suprapubic angle to the middle of the sacral promontory. – 12.5 cm
Ischial Spines – arise near the junction of the ileum and ischium and jut into the pelvic cavity They serve as a reference point during labor to elevate the descent of the fetal head into the birth canal. 10.5 cm
Pubic Arch – triangular space below the symphysis pubis. The head passes under this arch during birth. 1.5 – 2 c from diagonal conjugal
Coccyx -small triangular bone that articulates with the sacrum. It usually moves backward during labor to provide more room for the fetus. > 8cm in diameter
Sacrum – wedge-shaped bone formed by the fusion of five vertebrae. On the anterior upper portion of the sacrum is the sacral promontory which is another guide in determining pelvic measurements.
Types of Pelvis
Gynecoid -The most common female pelvis is the gynecoid type. The inlet is rounded, with the anteroposterior diameter a little shorter than the transverse diameter. This is the most favorable for a vaginal delivery.
Android – The normal male pelvis is the android type; however, it occasionally is seen in females. The inlet is heart-shaped.
Anthropoid – The inlet of an anthropoid pelvis is oval, with a long anteroposterior diameter and an adequate but rather short transverse diameter. This is the second most favorable for vaginal delivery.