Int J Gynaecol Obstei 17: 246-249, 1979
Concurrent Use of PGF2a/ Vibrations to the Cervix Uteri and Amniotomy to Induce Labor After Intrauterine Fetal Death Bengt Sorbe Department of Obstetrics and Gynecology, Central Hospital, Eskilstuna, Sweden
ABSTRACT Sorbe B (Dept of Obstetrics and Gynecology, Central Hospital, Eskilstuna, Sweden). Concurrent use ofPGFïa, vibrations to the cervix uteri and amniotomy to induce labor after intrauterine fetal death. Int J Gynaecol Obstei 17: 246-249, 1979 A triad consisting of (a) prostaglandin F^ infusion, (b) dilation of the uterine cervix by low frequency vibrations and (c) early low amniotomy was used to induce labor in ten women after intrauterine fetal death had occurred. Vaginal delivery was successful in all cases, with a mean inductionto-delivery interval of 5.4 ± 0.8 hours. Vibratory dilation effectively prepares the cervix for the intense prostaglandininduced uterine contractions and thereby reduces the risk of cervical laceration and fistula. The dilation of the cervical canal also makes an early low amniotomy possible and easy. This study demonstrates a highly effective, safe and relatively nontraumatic method for uterine evacuation after intrauterine fetal death.
INTRODUCTION T h e induction of labor after intrauterine fetal death once presented a serious problem for the obstetrician. Watchful expectancy or unsuccessful oxytocin stimulation was a source of anxiety for the patient and carried the risk of hypofibrinogenemia if the onset of labor was unduly delayed. T h e introduction of prostaglandins has partly reduced the problems of this clinical situation. Various routes of administration have all proved effective, but divergent rates of side effects have been reported (4, 6). O n e important obstacle still remains in the form of the unripe cervix uteri. Atypical cervical effacement and dilation leading to cervical laceration or fistula have been reported, especially in young primiparous women (2, 7). T h e reintroduction of laminaria tents as an adjunct to effect cervical dilation
Int J Gynaecol Obstei 17
has been recently advocated (8) but is not without disadvantages and hazards (5). In the pilot study described below, the author investigated, prospectively, the use of low-frequency vibrations to promote cervical maturation and dilation, in combination with amniotomy and intravenous infusion of prostaglandin F20 ( P G F 2 Q ) , for immediate evacuation of the uterus after intrauterine fetal death. MATERIALS A N D M E T H O D S Ten patients were studied consecutively. All were between 17 and 41 years of age (mean, 26.8 years), and their pregnancies were complicated by intrauterine fetal death occurring from 22 to 39 weeks' gestation (mean, 34.2 weeks). Three women were nulliparous and seven were multiparous, with parity ranging from 1 to 5. O n e woman had a five-year history of diabetes mellitus and was on insulin, whereas the other nine were apparently healthy. A patient with a previous cesarean section because of a marginal placenta previa and hemorrhage four years earlier was also included in this study. T h e time between the occurrence of intrauterine fetal death and the induction of labor varied from 1 to 17 days (mean, 5.7 days). Probable causes of the intrauterine fetal deaths are shown in T a b l e I. Treatment consisted of the intravenous infusion of 0.05 m g / m l PGF 2 „ (Amoglandin, Astra Lakernedel AB, Kvarnbergagatan, Sweden), in 55 m g / m l glucose. The infusion was started with 0.025 m g / min and was maintained at this rate for 30 minutes. If satisfactory uterine contractions were not obtained, the infusion rate was increased every two hours by 0.025 mg/min, up to a maximum of 0.150 m g / m i n . Uterine activity was monitored by an external tocograph (Roche-Kontron, Bromma, Sweden). Side effects were recorded continuously. As soon as clinically effective uterine contractions
Vibrations to the cervix to induce labor
were established, cervical scoring according to a modified Bishop scale comprising 0-10 points (Table II) was carried out. A Svedia cervix dilator (Svedia Dental-Industri AB, Enkòping, Sweden) was used to apply low-frequency vibrations to the cervix for ten minutes (Fig. 1). T h e vibrations are generated by an air-driven turbine with an eccentric disc placed on its rotating shaft. T h e tip of the dilator or spatula is thereby given a transverse, sinusoidal oscillatory motion. T h e equipment consists of three separate units: (a) a control panel, connected to a compressed air source (90-420 kPa), with a regulating valve for adjusting the vibratory frequency (60-120 Hz) and with a quick coupling for connecting (b) a handle with a built-in air-driven turbine, a vibration generator and a chuck for attaching (c) the cervical dilators or spatula. T h e frequency of vibration used was 90 Hz, and the amplitude at the tip of the dilator was 0.5 mm.
Cervical scoring was repeated after completing the vibrations. Amniotomy was then performed if the membranes were still intact. Analgesics, which were given liberally, included paracervical block (0.25% bupivacaine), pethidine (50-100 mg), methoxyflurane and N 2 0 / 0 2 (50:50), sometimes in combination with a tranquilizer (diazepam). T h e vibrating procedure caused no pain or discomfort to the woman.
RESULTS T h e mean induction-to-delivery interval was 7.6 ± 1.5 hours (mean ± SEM) for the nulliparous and 4.4 ± 0.8 hours for the muhiparous women. T h e average time required for all ten women was 5.4 ± 0.8 hours (median, 4.9 hours). All women were delivered within 12 hours (range, 1.3-11.2 hours). T h e mean times from the start of the PGF2„ infusion
Table I. Probable causes of the intrauterine fetal deaths. Patient No. 1 2 3 4 5 6 7
8 9 10
Weeks of Gestation
Fetal circulatory disturbance, fibrous transformation of the chorionic villi Stenotic changes of the umbilical vessels Umbilical cord complication (strangulation around one thigh) ABO isoimmunization Preeclampsia, placental insufficiency Diabetes mellitus Intrauterine growth retardation, placental insufficiency, ablatio placentae Acrania Unknown Umbilical cord complication (strangulation around the neck), esophageal atresia
22 31 31 32 36 37
38 38 38 39
Fig. 1. The Svedia cervix dilator (Svedia Dental-Industri AB, Enkòping, Sweden) relaxes the cervix with low frequency vibrations. It is powered by compressed air and consists of a control panel for adjusting vibration frequency, a handle with a vibration generator and cervical dilators and spatula.
Table II. A modified Bishop scoring system for induction of labor (range of scores: 0-10). Numerical Rating Factor Dilation (cm) Effacement (%) Station Consistency Position
0-0.5 0 -3 Firm Posterior
0.6-1.5 50 0, + 1 , + 2 Soft Anterior
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to the vibratory dilation procedure a n d / o r to the amniotomy were 59.3 ± 21.2 minutes and 100.7 ± 23.4 minutes, respectively. T h e mean cervical score was 3.7 before dilation a n d 7.2 after vibratory widening. T h e total dose of PGF2« required varied from 5 to 35 mg, with a mean dosage of 19.3 ± 2.8 mg per patient. Side effects of the PGF2„ treatment are summarized in Table III. No failures occurred in this series. All deliveries were uncomplicated, with seven vertex and three breech presentations. T h e male to female ratio was 6:4. T h e mean birth weight was 2111 ± 302 gm (range, 800-3760 gm). T h e third stage of labor was spontaneous in all but one case, in which curettage was necessary. T h e mean placental separation time was 9.0 ± 3.9 minutes, and the blood loss averaged 119.4 ± 24.8 ml (range, 25-300 ml). T h e type of and need for analgesia are shown in T a b l e IV. T h e vibratory dilation procedure per se did not influence the need for analgesics. All patients were discharged from the hospital in good condition within four days. No cases of uterocervical t r a u m a or signs of puerperal infection were recorded.
Table III. Side effects of PGF2„ infusion in ten patients. No. of Side Effects Patients Nausea/vomiting 3 Diarrhea 2 Headache 1 Superficial phlebitis 1 None 5
Table IV. The type and need for analgesia in ten women in the series. No. of women Narcotic analgesia Pethidine (50-100 mg)
Tranquilizers Diazepam (5-10 mg)
Inhalational agents N 2 0 / 0 2 (50:50) Methoxyflurane
Regional analgesia Paracervical block (0.25% bupivacaine) Pudendal block (0.25% bupivacaine)
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DISCUSSION Induction of labor in cases of intrauterine fetal death presents a n u m b e r of problems. T h e administration of prostaglandins by various routes has solved some of them. T h e problem with the unripe and obstructing cervix still remains, along with the risk of atypical cervical effacement and dilation leading to cervical laceration or fistula (2, 7). Other reported serious complications are acute blood loss, infection and failure to achieve vaginal delivery within a reasonable time (2). An ancient method for cervical dilation—the laminaria tent—has been recommended by some authors (3, 8); however, it is time-consuming and not without hazard (5). Complications due to infection (eg, by Clostridium species) led to the disappearance of the laminaria tent from clinical practice at the beginning of this century (8). T o avoid these problems, we have introduced low-frequency vibration to soften and dilate the cervix as an adjunct to prostaglandin uterine stimulation and to make an early low amniotomy possible. T h e vibration technique is a standard method in our obstetric department for shortening normal labor, especially the period of dilation (1). This technique is easy, rapid and without pain or discomfort to the woman. Low-frequency vibrations also have proved remarkably effective in preparing the cervix for the intense prostaglandin-induced uterine contractions, which are reflected in the considerable change in the mean initial cervical score from 3.7 to 7.2 and the short mean induction-todelivery interval of 5.4 hours. Amniotomy has been avoided previously both because of fear of infection (4) and because of technical difficulties in penetrating the narrow cervical canal. In this series, we have found no disadvantages with early low amniotomy, and it was readily performed after the vibratory dilation of the cervix. We believe that the triad of PGF2« infusion, dilation of the cervix by low-frequency vibrations a n d early low amniotomy offers an effective, safe and relatively nontraumatic method of solving the medical, psychologic and social dilemmas of intrauterine fetal deaths. REFERENCES
1. Dahlgren S: Shortening of labour, especially the period of dilatation with low frequency vibrations against cervix uteri—a clinical study. Acta Obstet Gynecol Scand (Suppl] 55, 1976.
Vibrations to the cervix to induce labor
2. Duenhoelter J H , Gant NF: Complications following prostaglandin F2o-induced midtrimester abortion. Obstet Gynecol 46:\8, 1975. 3. Duenhoelter J H , Gant NF, Jimenez J M : Concurrent use of prostaglandin F&, a n d laminaria tents for induction of midtrimester abortion. Obstet Gynecol 47.469, 1976. 4. Gordon H, Pipe N G J : Induction of labor after intrauterine fetal d e a t h — a comparison between prostaglandin E2 and oxytocin. Obstet Gynecol 45:44, 1975. 5. Green SL, Brenner W E : Clostridial sepsis after abortion with PGr?2