Electrical Inhibition of Human Preterm Contractions

The purpose of this study is to determine the effectiveness of a new method of preventing the
human preterm uterine contractions of labor during electrical monitoring. The objective is to
test a method for the inhibition of human preterm uterine contractions with an electrical
pacemaker, electrical inhibition (EI). The study will investigate EI associated changes in
preterm uterine contraction frequency as monitored by objective uterine tocodynamometry and
adjunct electromyography (EMG) and electrohysterogram (EHG). The endpoint is the
statistically significant EI induced decrease in the gold standard tocodynamometric monitored
preterm uterine contraction frequency. The adjunct EMG and EHG monitoring provides valuable
adjunct data about the electrical activity of the preterm uterine contractions and the effect
of EI on this activity.

The investigators hypothesize that human preterm uterine contractions can be safely and
objectively inhibited with a weak electrical current provided by an electrical inhibition
(EI)/uterine pacemaker device. This effect can be assessed by the use of a non-invasive
tocodynamometer. It has been previously been shown that the frequency of contractions during
preterm labor can be lowered by EI applied by the use of an intravaginal catheter carrying
electrodes similar to a cardiac pacemaker (Karsdon et al). The investigators hypothesize that
this effect relates to the timing and length of EI exposure.

Inclusion Criteria:

- Wong-Baker pain score ≤ 6

- Pregnancy Depression Scale score < 16

- Informed consent form signed and dated by patient

- Be willing and able to comply with study requirements

- Be between 18 - 50 years of age

- Be between 23 to 34 weeks pregnant with a singleton gestation

- Cervical dilation of ≤ 6 cm

- Normal spontaneous vaginal delivery (NSVD) expected.

- Be in preterm labor, as defined by the American College of Obstetricians and
Gynecologists and the American Academy of Pediatrics, as follows:

- Persistent uterine contractions (4 every 20 minutes, or 8 every 60 minutes)

- And any one or more of the following:

- Documented cervical change

- 1cm cervical dilatation and progressing

- > 80% cervical effacement

- Be admitted to Labor and Delivery with the diagnosis of preterm labor or preterm
contractions

Exclusion Criteria:

- Severe preeclampsia

- Severe abruption placenta

- Abnormal placentation (i.e. placenta previa)

- Rupture of amniotic membranes

- Active preterm labor with cervical dilation > 6 cm

- Exposed amniotic membranes

- Vaginal bleeding > 10 cc

- Frank chorioamnionitis

- Fetal death

- Fetal anomaly incompatible with life

- Severe fetal growth restriction (EFW < 5%)

- Uterine anomalies (i.e. bicornuate uterus, uterine didelphys)

- Mature fetal lung studies

- Maternal cardiac arrhythmias

- HIV, Hepatitis C, Hepatitis B

- History of herpes simplex virus (HSV)

- A permanent cardiac pacemaker

- A fetal cardiac arrhythmia

- Contraindication for tocolysis e.g. premature rupture of the amniotic membranes
allowing for ascending intrauterine infection with group B streptococcus or GBS (beta
hemolytic streptococcus, S. agalactiae) or other micro-organisms.

- IV or po narcotic pain medication < 12 hours prior to admission (regional anesthesia,
long acting oral maintenance opiates i.e. methadone, Suboxone, Subutex not included in
exclusion criteria)