Rupture of the uterus following treatment with 16-16-dimethyl E 2 prostaglandin vagitories

Rupture of the uterine body was found after induction of therapeutic abortion with vaginal suppositories containing 16,16-dimethyl prostaglandin E 2 in a 20-year-old primigravida. A short discussion is given on the cervical complications that can occur after prostaglandin induction of abortion, stating that rupture of the uterine body also can be seen. So far, no prostaglandin compound seems to avoid such complications.     

Prostaglandin-induced pregnancy termination: Further studies using gemeprost (16, 16 dimethyl-trans-Δ-PGE1 methyl ester vaginal pessaries in the early second trimester

The use of gemeprost (16, 16 dimethyl-trans-Δ²-PGE₁ methyl ester) vaginal pessaries for the termination of pregnancy in the early second trimester has been further investigated. Of 113 women between 12 and 16 weeks gestation, 93 (82%) aborted within 24 hours of the administration of 4.4 ± 0.1 1mg gemeprost pessaries. The mean induction — abortion interval was 881 ± 31 minutes. Successful abortion was achieved in 16 of the remaining 20 women after a second course of gemeprost pessaries without the need for oxytocin supplementation. There were no serious complications. Crampy abdominal pain and vaginal bleeding started after 275 and 756 minutes respectively. Twenty-two (19%) patients did not require pain relief during treatment, but 90 (80%) required parenteral opiates. Vomiting and diarrhoea occured in 16 (14%) and 23 (20%) cases respectively. The safe induction of therapeutic abortion in 96% of women using vaginal prostaglandin alone offers an acceptable alternative to surgical evacuation in the early second trimester.     

Decreased smooth muscle side effects with 16, 16-dimethyl-trans-delta2-PGE1 methyl ester in Japanese monkey (Macaca Fuscata Fuscata).

The smooth muscle stimulating activity of a new PGE1 analog, 16, 16-dimethyl- trans delta2 -PGE1 methyl ester (ONO-802) was evaluated by simultaneously recording the EMG of the uterus and intestines, along with urinary bladder pressure, and blood pressure in pregnant and non-pregnant Japanese monkeys (Macaca fuscata fuscata). Single intravenous injections of ONO-802 in increasing dosages (0.2-5 microgram/kg) were found to be 50-100 times or more effective in inducing uterine contraction than PGF2alpha and PGE1. A mild, transient gastrointestinal muscle stimulating activity was observed, but change in urinary bladder pressure and blood pressure was not evident. ONO-802 induced uterine contractions in the pregnant animals were 10 times greater than in the non-pregnant animals. These results suggest that ONO-802 may be a suitable clinical prostaglandin for use in therapeutic abortion.     

Uterine rupture as a complication of second trimester abortion using intraamniotic prostaglandin E2 and augmentation with other oxytocic agents

Two cases of ruptured uterus are presented following attempted induction of midtrimester abortion using intra-amniotic prostaglandin E₂ and augmentation with other oxytocic agents. With continued uterine stimulation the diagnosis of rupture may not be obvious and the diagnostic features are discussed. Patients of high parity appear to be particularly susceptible to uterine rupture during induced midtrimester abortion.     

Prostaglandin-induced pregnancy termination: further studies using gemeprost (16,16 dimethyl-trans-delta 2-PGE1 methyl ester) vaginal pessaries in the early second trimester

The use of gemeprost (16,16 dimethyl-trans-delta 2-PGE1 methyl ester) vaginal pessaries for the termination of pregnancy in the early second trimester has been further investigated. Of 113 women between 12 and 16 weeks gestation, 93 (82%) aborted within 24 hours of the administration of 4.4 +/- 0.1 1 mg gemeprost pessaries. The mean induction-abortion interval was 881 +/- 31 minutes. Successful abortion was achieved in 16 of the remaining 20 women after a second course of gemeprost pessaries without the need for oxytocin supplementation. There were no serious complications. Crampy abdominal pain and vaginal bleeding started after 275 and 756 minutes respectively. Twenty-two (19%) patients did not require pain relief during treatment, but 90 (80%) required parenteral opiates. Vomiting and diarrhoea occurred in 16 (14%) and 23 (20%) cases respectively. The safe induction of therapeutic abortion in 96% of women using vaginal prostaglandin alone offers an acceptable alternative to surgical evacuation in the early second trimester.     

Prostaglandin-oxytocin Enhancement and Potentiation and their Clinical Applications

The pharmacological phenomena of enhancement and potentiation of uterine response occur respectively when combinations of some prostaglandins and oxytocin are given serially and simultaneously to a patient. Employing these phenomena allows small doses of the drugs to achieve the same effects as a large dose given alone. In a pilot study of the use of the combination of prostaglandin and oxytocin for the induction of mid-trimester abortion seven of nine women were aborted within 48 hours. Side effects attributable to prostaglandin were eliminated or reduced in severity.     

Uterine trauma associated with midtrimester abortion induced by intra-amniotic prostaglandin F2α with and without concomitant use of oxytocin

Five of 80 (6.2%) nulliparous women sustained uterine trauma in association with midtrimester abortion induced by intra-amniotic prostaglandin F_2α and intravenous oxytocin. All five women suffered cervical lacerations, one extending to the lower uterine segment of the corpus and another associated with myometrial necrosis caused by cornual sacculation and ischemia. No uterine trauma was observed among 95 parous women aborted in the same fashion during this study. The different mechanisms of cervical dilatation in the parous woman and the nullipara are offered as an explanation for this difference. Thirty-nine other cases of uterine injury associated with the use of intra-amniotic prostaglandin F_2α from the literature were reviewed, and found to indicate that midtrimester abortion induced by intra-amniotic prostaglandin F_2α is associated with a significant risk of uterine trauma in the nullipara. The risk seems to increase with the use of oxytocin and with increasing gestational age.     

The antagonism by anti-inflammatory analgesics of prostaglandin f 2 alpha-induced contractions of human and rabbit myometrium in vitro.

The anti-inflammatory analgesic drugs, aspirin, indomethacin, phenylbutazone, mefenamic acid ibuprofen and flurbiprofen are shown to inhibit in a dose-dependent manner the force of contraction of isolated human pregnant myometrial strips which have been stimulated to contract by adding prostaglandin (PG) F2alpha to the tissue bath. These drugs and also flufenamic acid and salicin show a similar antagonism of the action of PGF2alpha with isolated rabbit non-pregnant myometrium. The ratio of the inhibitory concentration in vitro to the maximum plasma level after a normal dose in vivo suggests that phenylbutazone and possibly ibuprofen may be capable of inhibiting human uterine contractions in vivo. Patients who were treated with aspirin during induction of abortion using PGF2alpha during the second trimester of pregnancy showed no significant change in the induction-abortion interval compared with patients not taking aspirin.     

Single extra-amniotic injection of prostaglandin E2 in viscous gel to induce mid-trimester abortion.

In a preliminary study a single extra-amniotic injection of 1.5 mg of prostaglandin E-2 incorporated into an aqueous viscous gel was given to 24 patients aborted within 24 hours, and the mean induction-abortion interval (plus or minus S.E. of mean) was 13.5 plus or minus 1.5 hours. Vomiting occurred in seven patients, and transient severe uterine cramps, pallor, nausea, and shivering occurred in one patient immediately after injection. Complete abortion occurred in 20patients. A delay in the time taken to abort seemed to be associated with an immediate and rapid rise in uterine tone after the injection which required prompt analgesia; this probably reflected rapid decidual absorption and dissolution of the prostaglandins away from their site of action. The degree of distention of the catheter-retaining balloon did not influence abortion times.     

Intrauterine administration of prostaglandin by the extra-amniotic route

The present study was undertaken to explore whether abortion in the 13th-16th week of gestation could be induced by a single extra-amniotic injection of prostaglandin. A long acting prostaglandin analogue 15(S)-15-Methyl-PGF2alpha was utilized and different vehicles and injection techniques tried. The clinical results of the single injection method were compared with those using multiple injections of PGF2alpha as has been described earlier. It was found that approximately 80% of the patients aborted following a single injection of 750 mc 15-me-PGF2alpha and that the side effect rate was acceptable from a clinical point of view. The method seems to be an attractive alternative usable during the "difficult" period for induction of abortion, i.e., when the uterus is too large for vacuum aspiration but too small for abdominal puncture of the amniotic sac.     

Mid-trimester abortion with 15 (S) methyl prostaglandin F 2 alpha

The efficacy of intramuscular administration of 15 methyl (15S) prostaglandin F2alpha (PGF2a) in midtrimester pregnancy termination was evaluated in 16 healthy patients (mean age, 23.3; mean parity, 1.4; mean number of menstrual weeks, 16.1) by measuring dose response; oxytocin conversion; abortion time; side effects; intrauterine dynamics and progesterone withdrawal. Labor was monitored using extraovular balloon placed transvaginally; transcervically; and connected to a Physiograph machine. Patients not aborting within 48 hours after the first dose were considered failures. Blood samples were collected at 0, 3, and 6 hours and at abortion time for plasma progesterone measurement. Average dose given was 789 +or- 60 micrograms. Only 9 of 10 patients aborted within the prescribed 48 hours: 7 were complete abortions, and 2 were incomplete and required suction curettage. Mean induction to abortion time was 20.2 +or- 2.7 hours. Nausea, vomiting and diarrhea were the main side effects. The findings suggest that 15 methyl PGF2a in the dosages and routes prescribed is not as efficient as PGF2a. It is also suggested that prostaglandin affects the myometrium at 2 levels: 1) a membrane effect, and 2) a more fundamental intracellular regulatory effect which is necessary to initiate labor.     

Induction of abortion by intra- and extra-amniotic prostaglandin F2 administration

PGF2 alpha was administered intrauterine in 115 patients during the 11th to 20th week of pregnancy for abortion induction. An intra-amniotic method was used in 61 cases, an extra-amniotic one in 54 cases. Average total dose administered was 35.1 (range 5 to 65 mg) in the amniotic group and 6358 mcg (range 1500 to 14000 mcg) in the extra-amniotic group. The intra-amniotic group had an abortion rate of 92% and a 74% rate of side effects, mainly gastrointestinal irritation. Corresponding figures for the extra-amniotic group were 72% and 54% respectively. In the extra-amniotic group, doses of 4750 mcg or more increased the abortion rate up to 80% and side effects up to 64%. There were no serious complications. The intra-amniotic approach of prostaglandin induction is suitable for second trimester therapeutic abortions. The extra-amniotic approach is useful in cases of fetus mortuus and hydatiform mole.     

Blood Coagulation Changes during Mid-trimester Abortion Induced by Prostaglandin F2α

Serial studies on the coagulation system were made during second-trimester abortion induced by extra-amniotic, intra-amniotic, vaginal, and intravenous prostaglandin F₂α. No significant changes were found in the prothrombin time, partial thromboplastin time, or levels of fibrin-fibrinogen degradation products. An increase in the activity of factor X occurred with all routes of administration; the activity of factor VIII increased during extra-amniotic, vaginal, and intravenous administration; factor V activity increased during extra-amniotic and vaginal administration; and the activity of factor VII-X complex increased slightly at the time of abortion with all methods.The findings suggest that though prostaglandin induction of second-trimester abortion produces changes in the coagulation system the effects are much less than those which accompany induction of abortion by hypertonic saline or abdominal delivery in late pregnancy.     

Coagulation Changes during Termination of Pregnancy by Prostaglandins and by Vacuum Aspiration

Serial studies on coagulation factors were performed on 12 patients having termination of mid-trimester pregnancy by extra-amniotic prostaglandin F₂α and 11 patients terminated by vacuum aspiration during the first trimester. A significant change in the activity of factors V, VII and X, VIII, and X, and a decrease of the prothrombin time and platelet count were found with prostaglandin termination but no such changes occurred during vacuum aspiration. These findings suggest that the coagulation system is activated during induction of mid-trimester abortion with extra-amniotic prostaglandin F₂α. This is probably related to the physiological changes in the coagulation mechanism which occur by the second trimester of pregnancy. Termination of pregnancy in the mid-trimester may, however, be expected to give rise to defective blood coagulation and thromboembolic complications.     

Prostaglandin E2 induced abortion with vaginal suppositories in a contraceptive diaphragm

PGE2 (prostaglandin E2), 20 mgm vaginal suppositories were administered to 2 groups of women seeking termination of pregnancy. 1 group had the suppository inserted inside a contraceptive diaphragm. Statistical comparisons were carried out for instillation to abortion time, side effects, and intrauterine pressure parameters. The usage of the diaphragm significantly reduced side effects, and resulted in an instillation to abortion time of 12.8 + or - 2.3 hours with no failures. The quantitative analysis of the uterine pressure recordings revealed activity significantly different than that seen with intraamniotic or extraovular PGF2alpha. The development of uterine activity simulates that of normal labor in that elevation of resting pressure does not occur and maximum active pressure evolves slowly.     

Prostaglandin E2 receptor subtype EP-2 is not involved in the induction of non-pregnant guinea pig uterine contractions associated with terminal pregnancy

Prostaglandin E2 (PGE2) exerts its biological effects through 4 different receptor subtypes, EP-1, EP-2, EP-3, and EP-4. Recently we have demonstrated the importance of the prostaglandin E2 receptor subtype EP-2 in the healing of bone defects and fractures. This discovery led to the identification of CP-533,536, an EP-2 selective agonist, a promising therapeutic alternative for the enhancement of bone healing and the treatment of fractures (J Bone Miner Res 18 (2003) 2033). PGE2 has a myriad of effects throughout the body including the induction of uterine contractions, which results in termination of pregnancies. Our objective in this study was to determine the role of the EP-2 receptor and specifically that of CP-533,536, an EP-2 specific agonist, to induce uterine contractions and terminate pregnancy in guinea pigs, an animal model of human pregnancy. Preliminary experiments confirmed earlier reports that the guinea pig uterus was more sensitive than that of the rat. The guinea pig uterus contains the four PGE2 receptor subtypes, and ex vivo treatment of the uterus with PGE2 as expected causes profound uterine contractions. However, using receptor selective prostaglandin agonists including CP-533,536 we showed that the EP-1 and 3 receptors not the EP-2 receptor is responsible for the induction of uterine contractions of PGE2. Further, CP-533,536 did not antagonize the ability of PGE2 to induce uterine contractions in this model.     

Inhibition of prostaglandin induced uterine activity in the second trimester of pregnancy by beta-mimetic adrenergic agents

Clinical research was undertaken to study the effect of 2 beta-mimetic adrenergic agents, orciprenaline and ritodrine, on uterine activity produced by administration of PGF2alpha (prostaglandin) in the 2nd trimester of pregnancy. Subjects were 8 women admitted to the University Hospital in Uppsala, Sweden, for a therapeutic abortion in the 16h-24th week of pregnancy. 4 were given orciprenaline extraamniotically and 4 were given ritodrine intraamniotically. Infusion of both the substances caused a decline in the frequency and intensity of uterine activity, which had previously been induced by administration of PGF2alpha. For both drugs, the reduction in uterine activity was dose-related. Both drugs caused an increased maternal heart rate. Ritodrine also produced a rise in systolic and a fall in diastolic pressure. No other side effects were observed. Discontinuation of the drug infusion caused uterine activity to increase. Results of the study demonstrate that beta-mimetic adrenergic agents are capable of inhibiting PG effects on uterine activity. To achieve a significant reduction, however, the dose must be large enough to cause tachycardia and palpitation, side effects tolerated well by the patients.     

Prostaglandin-induced Abortion: Assessment of Operative Complications and Early Morbidity

A total of 626 patients undergoing a prostaglandin-induced abortion, the majority in the second trimester, have been analysed for complications occurring during inpatient treatment. Of the last 155 consecutive patients 143 were critically assessed six to eight weeks after abortion for morbidity occurring during their early recovery period.Blood loss of 250 ml or more occurred in 68 patients, pyrexia in 34, pelvic infection in three, and readmission in 14 of the 626 patients studied, and a transfusion was required in eight.Bleeding after abortion stopped within six weeks in all 143 of the 155 consecutive patients assessed but three required readmission for uterine curettage. Menstruation was re-established within six weeks of abortion in 106 patients.The incidence of operative morbidity was similar to that reported for first trimester abortion and better than that in most reported series of second trimester abortions.     

The use of oral prostaglandin E2 in the management of intrauterine fetal death

12 otherwise healthy patients with intrauterine fetal death 1 to 6 weeks earlier were treated with oral prostaglandin E2. 9 of the 12 patients delivered within 48 hours after treatment began. 2 others delivered with 48 hours after unsuccessful treatment ceased. In a third patient the cervix relaxed after treatment, and the uterine contents were removed by curettage. No serious complications, such as hemorrhage occurred. The uterus seemed surprisingly responsive to oral prostaglandin E2 in cases of intrauterine fetal death.     

Intramuscular 16-phenoxy PGE2 ester for pregnancy termination.

A new PGE2 derivative (16-phenoxy PGE2 methyl sulfonylamide sulprostone) was administered by the i.m. route to 48 women pregnancy in any of the three trimesters. The indications for pregnancy interruption were either serious medical problems in intact pregnancies (21 cases) or due to fetal death in utero (27 cases). Single doses of 500 micrograms were repeated every 4 hours in the former group or every 6 hours in the latter category for a maximum period of 24 hours. The treatment was successful in 81% of intact pregnancies and in 92.6% of fetal death cases with an overall mean induction interval of 12.9 hours. More than half the subjects did not experience any side effects apart from mild or moderate uterine colics. An overall mean of 1.4 episodes of vomiting or diarrhoea per induction trial was quite acceptable from the clinical point of view. The absence of serious complications in the group of critically sick women speaks in favor of the relative safety of the drug.