Artificial abortion at midpregnancy by mechanical stimulation of the uterus. A review of 20 years' experience with current methods in Japan

Human decidua and uterine contractility

Physiological saline solution injected into the uterus by the extraamniotic route was found to damage the decidua and rupture its lysosomes. The mechanism by which this procedure provokes abortion may be through the release of lysosomal phospholipase A2 (EC 3.1.1.4), an enzyme thought to regulate the formation of polyunsaturated fatty acids utilized for prostaglandin synthesis. A similar sequence of events may be involved in the initiation of spontaneous labour, since decidual cells obtained at elective Caesarean section at term exhibited degenerative changes and signs of release of a lysosomal marker enzyme. The cause of this release is unknown.

MID-TRIMESTER MTP USING ENDOCERVICAL PGE2 GEL AND SERIAL INTRAMUSCULAR CARBOPROST

60 cases of mid-trimester pregnancy were terminated using endocervical PGE2 gel (for achieving cervical priming) followed by serial intramuscular injections of carboprost. In this prospective study, 56 cases were multiparae with gestational age varying between 15-22 weeks. The induction-abortion-interval was 8.4h ± 0.8h with a success rate of 100%. The incidence of incomplete abortion was 5% and check curettage was performed in 16.6% cases. Gastrointestinal side effects were common. Vomiting occurred in 42% cases and diarrhoea in 50%. Febrile morbidity was seen in 8.3% cases. There were no complications of the procedure. The method was highly acceptable to the patients being non-invasive and allowing ambulation throughout. This method of elective mid-trimester abortion is an effective alternative to the other commonly used methods like extra-amniotic ethacridine lactate or intra-amniotic hypertonic saline instillation.

Dilapan tent-gemeprost regimen vs. combinations of extra-amniotic Rivanol-Laminaria/Lamicel and oxytocin for second trimester abortion

OBJECTIVE

To compare a new regimen for second trimester abortion using Dilapan and vaginal gemeprost suppositories with extra-amniotic Rivanol instillation and oxytocin i.v. immediately or 16 h after instillation.

METHODS

A prospective study was performed in 153 women to analyze the induction-abortion interval, the use of analgesics and the complication rate. Wilcoxon's rank sum test was used for statistical evaluation.

RESULTS

The mean induction-abortion interval was significantly shorter in the Dilapan-gemeprost-treated women than in the immediate or 16-h Rivanol-oxytocin-treated women, 12.5 vs. 23.3 and 26.8 h, respectively. The 24-h cumulative abortion rate was 91% in the former group vs. 49% and 61%, respectively. The use of analgesics was less frequent among the Dilapan-gemeprost-treated women, whereas the complication rate did not differ.

CONCLUSIONS

The Dilapan-gemeprost treatment was advantageous with respect to a shorter induction-abortion interval and ease of handling. However a minority of women do not respond to this treatment and it is therefore necessary to employ alternative methods to complete the abortion in these cases.

Microbiological studies in mid-trimester abortion with Emcredil versus normal saline

In 40 mid-trimester abortion seekers, in whom abortion was induced by extra-amniotic normal saline or Emcredil, microbiological studies were carried out before induction and at 24 hours. It was observed that there was no difference in the isolation of organisms from vagina and cervix of these subjects between 0 hours and 24 hours. Thus, this study shows that leaving the catheter in the extra-amniotic space until it is expelled spontaneously does not increase the risk of ascending infection. At the same time, leaving the catheter in-situ until it is expelled spontaneously reduces the induction-abortion interval appreciably.

Fetal viability does not affect the onset of stretch-induced labor and the increase in amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels

The role of the fetus in the onset and progress of stretch-induced labor and in the change in amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels was evaluated in six normal pregnant women (group 1) and six women whose fetuses had been dead for more than one week (group 2). The uterus was distended by a balloon inflated with physiologic saline. Regular uterine contractions occurred, and increased in all patients. Within 21 hours, all patients delivered a normal baby in group 1 and a macerated fetus in group 2. There was no significant difference in induction-delivery interval between the two groups. Both groups showed a significant and similar range of increases in the levels of amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite during treatment (P less than 0.001). Thus, the fetus has no functional role in the onset and progress of stretch-induced labor or in the rise of amniotic fluid prostaglandin F2 alpha and plasma prostaglandin F2 alpha metabolite levels.

Second trimester pregnancy termination using extra-amniotic ethacridine lactate

OBJECTIVE

To investigate the efficacy of ethacridine lactate by the extra-amniotic route for second trimester pregnancy termination and its associated complications.

DESIGN

Retrospective study of women undergoing second trimester termination, over 3 1/2 years, with extra-amniotic ethacridine alone, or extra-amniotic ethacridine supplemented later by extra-amniotic 15-methyl prostaglandin F2 alpha.

SETTING

Teaching hospital in Bombay.

PATIENTS

315 consecutive women undergoing late abortions with extra-amniotic ethacridine. Demographic features were similar in the two groups.

INTERVENTIONS

In group 1, 207 women had 150 ml of 0.1% ethacridine lactate injected slowly into the extra-amniotic space. In group 2, 108 women had the initial injection supplemented 6 h later by an extra-amniotic injection of 250 micrograms (1 ml) of 15-methyl prostaglandin F2 alpha.

MAIN OUTCOME MEASURES

The occurrence of abortion following the induction procedure. The development of complications such as haemorrhage, infection, or injury to the uterus or cervix.

RESULTS

The method was successful in 191 women (92%) in group 1 and in 106 (98%) in group 2. The median induction-abortion intervals were 35 and 19 h, respectively (Mann-Whitney U test, P less than 0.001). The corrected complication rate was less than 10% (30 women), with unplanned uterine evacuation in 6% (20), haemorrhage in 1% (4), and pelvic infection in 4% (14).

CONCLUSION

The use of extra-amniotic ethacridine lactate provides an effective and safe treatment method for second trimester legal abortion. The induction-abortion interval can be appreciably reduced by supplementary prostaglandin.

Intrauterine administration of drugs for termination of pregnancy in the second trimester

Medical methods have been used for many years to terminate mid-trimester pregnancy, ranging from irritant chemicals and traditional plants to ecbolic agents and solutions instilled locally into the uterus. These methods had serious limitations, with relatively high rates of maternal mortality and morbidity. Surgical evacuation requires special skills not available to all practitioners and many doctors consider second trimester dilatation and evacuation as a surgical taboo. In recent years several approaches evolved and reached the clinics, presenting safer and more effective options. Intra-amniotic instillation of hypertonic solutions, particularly saline or urea, proved in many hands to be a good method for pregnancies beyond 15 weeks of gestation. Due to a long latency period after instillation, these agents are often supplemented by an intravenous oxytocin infusion. Extraovular hypertonic saline or ethacridine (Rivanol) have their advocates, particularly in the grey-zone of pregnancy range from 13-15 weeks. In the last two decades, intrauterine prostaglandins were added to the methods in current use. Extra-amniotic prostaglandins (E2, F2 alpha or 15-methyl F2 alpha) were originally given in repeated doses or as a continuous local drip, but later a single instillation was used, usually mixing the drug with a viscous solution or gel. Intra-amniotic prostaglandins, in much higher doses, particularly the 15-methyl analogue, proved highly effective and relatively safe, especially when combined with laminaria tent insertion in the cervix. Various combinations of methods have provided a wide spectrum of data which is difficult to evaluate at present. Studies comparing different methods were mainly attempted in the mid-seventies. The outcome raised many pertinent questions and left many major issues unresolved. Most of the comparisons were not randomized or well-controlled and only referred to the natural prostaglandin compounds. The analogues, however, seem to offer several advantages and the role of additional methods such as laminaria or antiprogestins remains to be further evaluated.

Late abortion practice in a teaching hospital in India

The medical records of 2055 patients undergoing late abortions were reviewed. These represented 15% of all abortions induced over 10 years. In 52%, abortion was performed between 13-16 weeks, and in 25% at or after 20 weeks. Abortion was requested for risk to health in 55% and for failed contraception in 40%. Surgical techniques were used in 39%. There was a trend to use vaginal surgical procedures increasingly, and intraamniotic saline decreasingly. Extraamniotic ethacridine lactate was used in 12%. Because of the cost, prostaglandin infusions were restricted to 2.5%. Planned evacuation of retained products following a medical procedure was performed in 71%; concomitant sterilization in 24%. The complication rate settled at 11% of which 4% were retained products of conception. Complications increased overall with advancing gestational age, and particularly from 15 weeks onward with vacuum aspiration (p0.05) and with dilatation and curettage (p0.05). Cervical injury increased with advancing gestation (p=0.01). In developing nations, there is a pressing need to educate illiterate women to request abortion earlier.

Induction of second trimester abortion by intraamniotic instillation of Rivanol (ethacridine) combined with oxytocin infusion

We report our experience of 0.1% intraamniotic Rivanol in the interruption of 100 midtrimester pregnancies (15-24 gestation weeks). The mean injection to abortion interval was 37.2h and there were no complications. Intraamniotic Rivanol injection combined with oxytocin infusion seemed an effective and safe method for terminating second trimester pregnancies.

Conditions of the cervix for the increase of plasma levels of 13,14-dihydro-15-keto-prostaglandin F2 alpha after amniotomy at term

Amniotomy was performed in 12 multiparas at term but not in labor. In 6 of these patients (group I), the fetal head and cervix condition were favorable for amniotomy, and in the other 6 (group II), they were not favorable. In all group I patients, a sudden and progressive descent of the fetal head, and onset and progress of labor were noted within 5 hours. Plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) levels increased significantly (P less than 0.05) in 4 of these cases with time. In group II patients, descent of the head was less than that in group I patients (P less than 0.05), and neither strong labor nor rise of PGFM levels was noted within 5 hours. These data support our view that amniotomy at an appropriate time results in the onset and progress of labor, and the rise of plasma PGFM in virtue of the sudden and exponential increase of the head to cervix force, but amniotomy at an inappropriate time does not, because this force is unchanged.

Experimental evidence for the progress of labor with the increase in the force of cervical dilatation after rupture of the membranes

To examine the mechanical forces involved in cervical distention, actual tensions of the fetal membranes up to the bursting level were measured experimentally with the use of five circular membrane holders that simulate various cervical dilatations (radii 1 to 5 cm). The results show that the force of cervical dilatation with the head alone increases remarkably as the cervix dilates, and this force is always larger than that when the membranes are intact. Thus the membranes appear to interfere with effective cervical dilatation and progress of labor after fixation of the fetal head to the cervix.

Plasma levels of 13,14-dihydro-15-keto prostaglandin F2 alpha, estrogens, and progesterone during stretch-induced labor at term

The uterus of six healthy multiparous women at term was mechanically stretched by a rubber catheter and balloon. Apparent labor was inaugurated in all cases within 5 hours and increased progressively with time. Advanced cervical softening and dilatation were also evident after the stretch treatment. Significant increases in the levels of 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were observed with the progress of treatment (P less than 0.01). Plasma estrogens and progesterone levels did not change significantly during the treatment (P greater than 0.05). Stretching and/or resulting uterine contractions appear to induce the secretion of prostaglandin F2 alpha (PGF) from the organ, which in turn seems to be involved in both cervical softening, and the onset and progress of labor, under stable conditions of plasma estrogens and progesterone.

Nelaton catheter in non-gravidas for a safe and gradual cervical softening and dilatation: a possible involvement of prostaglandins

A short Nelaton catheter (No. 7 or 8; diameter: 4.5 or 5 mm) was inserted for 24 hours in the uterine cervix in 89 non-gravidas, including 67 nulliparas. Patients were distributed in four groups depending on the purpose of cervical dilatation: I.U.D. insertion (n = 16), diagnostic curettage (n = 37), hysteroscopy (n = 12), and insertion of radiation applicator in uterine cancer (n = 24). Comparative studies with a smaller number of patients (n = 18) were also performed with a laminaria tent prior to study of the Nelaton catheter. In both the Nelaton and laminaria groups, significant cervical softening and dilatation of the cervix was attained in all cases. After treatment, a Hegar dilator No. 6 to 10 (diameter: 6.5 to 8.8 mm) could be inserted easily without resistance and without the necessity for anesthesia in either group. In the Nelaton catheter group, the tigher the catheter in the cervical canal upon insertion, the higher was the efficiency. The overall efficiency of the Nelaton catheter did not differ significantly from that of laminaria. The Nelaton catheter had several advantages over that of laminaria. No serious side-effects were encountered during the use of the Nelaton catheter compared with laminaria. This simple device proved to be useful as a convenient clinical instrument, particularly in the field of fertility control and for diagnostic and therapeutic purposes of intra-uterine abnormalities. The possible involvement of prostaglandins in the mechanism of action of the catheters is discussed.

F prostaglandin levels in amniotic fluid during balloon-induced cervical softening and labor at term

Mechanical stretching of the uterus was applied to seven term patients not in labor with unripe cervix by means of intra-uterine application of a rubber balloon. Significant cervical softening, and initiation and progress of labor was achieved in all cases. Serial analyses of the F prostaglandins (PGF) in amniotic fluid were performed before and at given intervals of cervical dilatation. Before the application of stretch, the levels of PGF varied greatly: the values in 5 cases were measureable but low (less than 645 pg/ml) and in two cases the levels were below the sensitivity of the assay (less than 50 pg/ml). Large fluctuations of the levels were noted in many cases during the treatment. However, the rise of the PGF values was significant with the progress of cervical dilatation compared to the pre-treatment values (P less than 0.05 at both 3-4 and 5-6 cm, and P less than 0.01 at 9-10 cm). It was concluded that the increased release of PGF in amniotic fluid is mediated by uterine stretching, and that upon being released PGF is probably involved in the cervical softening an progress of labor.

Nelaton catheter versus laminaria for a safe and gradual cervical dilatation

During the first trimester of abortion, the Nelaton catheter can be used for the gradual, safe softening and dilatation of the cervix, just as the laminaria. Based on the results obtained from more than 1000 cases, we reached the conclusion that the effectiveness of cervical softening by the Nelaton catheter is almost equal to the laminaria and its efficiency in the dilatation of the cervix is similar or slightly inferior to the laminaria. In addition, this simple device had less risks when compared to those associated with laminaria. Therefore, the Nelaton catheter appears to be as effective as the laminaria for a safe and gradual cervical dilatation.

Abortion during mid-pregnancy by rivanol-catheter supplemented with PGF2 alpha drip-infusion or quinine hydrocholoride

Abortion during mid-pregnancy was performed in 200 patients by extra-amniotic insertion of Nelaton catheters and instillation of 0.1% rivanol solution. To shorten the abortion time, quinine hydrochloride was given orally in one group (n=100), and intravenous infusion of prostaglandin F2 alpha (PGF2 alpha) was undertaken in the other group (n=100). The abortion rate after 72 hours was higher in the PGF2 alpha group (96%) than that in the quinine group (91%), but the difference was not statistically significant. The abortion time was significantly shorter in the PGF2 alpha group than in the quinine group (p less than 0.01). This method, together with supplementary treatment with oxytocic substances, proved to be an effective mid-pregnancy abortion method. The risks of endometritis, gastro-intestinal complications, and/or heavy bleeding either during or post-abortive were minimal.

Extraovular instillations of normal saline for termination of midtrimester pregnancy

Midtrimester abortion by extraovular instillation of normal saline was performed in 50 patients. All 50 aborted following the procedure, and there were no complications except for one case of endometritis that was successfully treated by antibiotics. The mean abortion time was 33 hours, without added oxytocin, and 30 hours when pitocin was administered intravenously. The extraovular route eliminates the necessity for amniocentesis, with its associated risks. By using normal saline instead of pharmacologic agents such as urea, glucose, hypertonic saline, prostaglandins, we were able to eliminate the complications related to drug side effects.

The potential reduction of medical complications from induced abortion

Reducing medical complications resulting from induced abortion by identifying the safest and most appropriate procedures(s) for each gestational age is the purpose of this study. Data on all women who had induced abortions at all hospitals in the State of Hawaii where such procedures were performed between March 11, 1970, when the new abortion law went into effect, and June 30, 1974 were analyzed. Study findings show that if the abortion procedure with the least risk of complications at each length of gestation were selected a reduction in the complication rate of nearly 30% could result.

Reported live births following induced abortion: two and one-half years' experience in Upstate New York

Thirty-eight live births following induced abortion were recorded in Upstate New York between July, 1970, and December, 1972. Twenty-six followed saline-induced abortion; twelve of these occurred at one hospital, and eight were associated with one physician. Underestimation of gestation and exchange of inadequate volumes of amniotic fluid and hypertonic saline produced concentrations insufficient to cause intrauterine death. Viable infants with iatrogenic central nervous system damage from salt poisoning are a possible consequence of improperly planned saline-induced abortions. These births provide further evidence for encouragement of contraception and early termination of unwanted pregnancy.

Placental pathology in midtrimester pregnancies interrupted by intra-amniotic injection of hypertonic urea

The histological appearances of 52 placentae from patients who had a urea-induced second trimester abortion were studied. Extensive subchorionic intervillous fibrin deposition and swollen degenerated stromal cells (probably Hofbauer cells), were found both in the placenta and membranes. Between urea injection and abortion, serial vaginal smears showed signs of progesterone deficiency. The urea-induced placental and fetal damage was similar to that seen with hypertonic saline.