Electrohysterography compared to external tocodynamometer and intra-uterine pressure catheter for uterine contraction monitoring during term labor.

In order to be eligible to participate in this study, a subject must meet all of the following criteria: women with a singleton pregnancy and gestational age between 37 and 42 weeks, in active labor with a fetus in cephalic presentation, ruptured membranes and fetal scalp electrode. We will apply strict criteria regarding diagnosis of labor: a pregnant woman needs to have regular painful contractions at least three each ten minutes, and a fully effaced cervix with minimum 3 centimeters of dilation.

A potential subject who meets any of the following criteria will be excluded from participation in this study: women under the age of 18 years old, women with a multiple pregnancy, women with signs of fetal distress (abnormal CTG requiring immediate intervention), women with a positive Group B streptococcus status in urine or vagina, and women with a positive hepatitis B/C or HIV serology. Contraindications to IUPC placement are uterine bleeding of undetermined origin, a suspected placenta praevia, vasa praevia, and signs of intrauterine infection (maternal fever >38C with fetal tachycardia >160 beats per minute). Contraindications to EHG placement are dermatologic diseases of the abdomen precluding preparation of the abdomen with abrasive paper, women in labor taking a shower or bath and women connected to external or implanted electrical stimulators.