Tj. Garite et al., THE INFLUENCE OF ELECTIVE AMNIOTOMY ON FETAL HEART-RATE PATTERNS AND THE COURSE OF LABOR IN TERM PATIENTS - A RANDOMIZED STUDY, American journal of obstetrics and gynecology, 168(6), 1993, pp. 1827-1832
OBJECTIVES: Our study was designed to evaluate the effects of routine
elective amniotomy on the frequency and severity of abnormal fetal hea
rt rate patterns and on the course of labor and the need for oxytocin
augmentation. STUDY DESIGN: A randomized, controlled trial was conduct
ed at term in patients in active labor who were randomly selected to u
ndergo elective amniotomy (amniotomy group) or left intact with amniot
omy reserved for specific indications (intact group). RESULTS: Four hu
ndred fifty-nine patients were studied (235 in the amniotomy group vs
224 in the intact group). Average cervical dilatation at rupture was 5
.5 cm in the amniotomy group and 8.1 cm in the intact group. Analysis
of fetal heart rate revealed more mild and moderate variable decelerat
ions in the active phase of labor in the amniotomy group but no differ
ence in the frequency of more severe decelerations or operative delive
ries. In the intact group the need for oxytocin was twice as common (7
6 in the intact group vs 36 in the amniotomy group, p = 0.000005), and
the active phase of labor was considerably longer (5 hours 56 minutes
in the intact group vs 4 hours 35 minutes in the amniotomy group). Ne
onatal outcome was similar in the two groups. CONCLUSIONS: Elective am
niotomy appears to increase the likelihood of umbilical cord compressi
on in the active phase of labor and results in more mild and moderate
variable decelerations, but it does not result in more severe abnormal
fetal heart rate patterns or more operative intervention. Elective am
niotomy does, however, shorten the active phase of labor and decreases
the need for oxytocin augmentation.