Electrical Inhibition (EI): A Preliminary Study To Inhibit Preterm Labor And Preterm Birth

Electrical intervention (EI) uses bipolar, constant-current (1-20 mA), square-wave pulses in
20% duty cycles. Women in active preterm labor have an electrode catheter placed into the
posterior fornix of the vaginal canal. The EI current is given up to 80 minutes while
monitoring tocodynamometric (toco) contractions and adjunct electrohysterographic (EHG)
activity while continuously monitoring maternal vital signs, fetal heart rate and
electrocardiogram (fECG). The study includes a pre-EI control period (C1); the EI period,
when a 10-second current burst is delivered only during a contraction; and a post-EI control
period (C2). The whole study will take a maximum of two hours.

The uterine toco contraction frequency and adjunct EHG electrical activity are analyzed for
changes caused by EI. Changes in maternal vital signs, fetal heart rate and fECG will
determine EI side-effects.

Inclusion Criteria:

- between 24 to 34 weeks pregnant with a singleton gestation;

- in preterm labor as defined by the American College of Obstetricians and Gynecologists
and the American Academy of Pediatrics,78 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

- anticipate a normal spontaneous vaginal delivery (NSVD).

- at least 18 years of age

- signed a written Informed Consent Document

- willing and able to comply with study requirements

Exclusion Criteria:

- severe preeclampsia

- severe abruption placenta

- rupture of amniotic membranes

- frank chorioamnionitis

- fetal death

- fetal anomaly incompatible with life

- severe fetal growth restriction (EFW <5%)

- mature fetal lung studies

- maternal cardiac arrhythmias

- a permanent cardiac pacemaker

- a fetal cardiac arrhythmia

- contraindication for tocolysis