The Effect of Intravaginal Prostaglandin F2α on Labour after Spontaneous and Artificial Rupture of the Membranes

Summary: The effect on labour of 50 mg intravaginal PG F_2α or a standard intravenous oxytocin regimen was compared in 2 randomised trials involving a total of 83 patients, 23 of whom had experienced spontaneous rupture of the membranes (S.R.O.M.) and 60 of whom had artificial rupture of the membranes (A.R.M.) to induce labour. In each trial, labour had not been initiated by membrane rupture alone. In both trials only 20% of the patients receiving PG F_2α required further augmentation of labour with intravenous oxytocin. The mean length of labour in patients receiving PG F_2α was 2.5 hours shorter in the A.R.M. trial and 3.0 hours shorter in the S.R.O.M. trial than the mean length of labour in patients receiving intravenous oxytocin (P < 0.01). In the A.R.M. trial, the PG F_2α-treated group had significantly less analgesic requirements (P < 0.001). Although more normal deliveries occurred in the patients treated with PG F_2α than oxytocin in both trials, die numbers did not reach statistical significance.
No side effects occurred in the PG F_2α-treated patients or their babies and this method was much preferred by patients and nursing staff alike.     

The Use of Prostaglandin F2α for the Induction of Mid-Trimester Abortion

Summary: Ninety-eight patients were given prostaglandin F_2α for the induction of mid-trimester abortion. In 42 the PGF_2α was administered by the extra-amniotic route and 37 aborted. A further 56 received the PGF_2α intra-amniotically and 55 aborted. Dose regimens are compared.     

Termination of Pregnancy by Intra-uterine Prostaglandin F2α

Summary: Fourteen pregnancies between the 12th and 19th weeks of gestation were terminated by intra-uterine administration of prostaglandin F_2α. In 7 patients the method of administration was transcervically into the extra-ovular space; in the other 7, administration was directly into the amniotic sac. The methods of administration, the doses used, the side effects and results are discussed. The findings indicate that intra-amniotic administration is the procedure of choice: firstly, because of the incidence of genital tract infection after transcervical administration; secondly, because 3 patients in the transcervical group had incomplete abortions and required anaesthesia for curettage; and finally, the induction-abortion interval was significantly less when the drug was administered into the uterine cavity.     

Vaginal Prostaglandin F2α Gel Before First Trimester Termination of Pregnancy

Summary: Tylose gel containing either 10 mg prostaglandin F_2α or sterile water was inserted into the posterior vaginal fornix of 130 patients either 12 hours or 4 hours before suction curettage. No benefit in terms of cervical softening or blood loss was noted in patients who received the prostaglandin gel.     

The Safety of Vaginal Prostaglandin F2α for the Stimulation of Labour

Summary: In an audit of 15,102 consecutive deliveries between 1986 and 1991, 3,168 labours were induced with intravenous oxytocin and 824 with 40 mg prostaglandin F₂a (PGF₂α) vaginal gel. Four hundred and twenty women received PGF₂α alone and 404 received PGF₂α followed by oxytocin. The main aim of the study was to audit the safety of PGF₂01 gel to stimulate labour. There were no maternal or neonatal complications attributable to this therapy. In particular, there were no cases of uterine rupture or hyperstimulation requiring surgical or pharmacological intervention. There was little difference in the evidence for fetal distress between induction methods. Although the prostaglandin and oxytocin groups were not comparable in all respects, the results of this large retrospective study confirmed the results of smaller prospective randomized trials showing a significantly shorter labour and reduced analgesia, surgical delivery and postpartum haemorrhage rates in women treated with PGF₂α alone. This is the largest reported series of PGF₂α induced labours and provides evidence of its safety and is in keeping with physiological data suggesting that PGF₂α is the main prostaglandin and oxytocic associated with normal progressive labour. Its apparent safety and potential to reduce both intervention in labour and postpartum complications merits greater attention.     

Preoperative Cervical Dilatation: A Trial of Laminaria Tents and Prostaglandin Fα2 Gel

Surgical damage to the cervix in patients undergoing termination of pregnancy may be responsible for serious complications in subsequent pregnancies. Sixty nulliparous women undergoing first trimester termination of pregnancy were randomly allocated to 3 treatment groups, one using laminaria tents preoperatively, one using intracervical PGF2 alpha gel preoperatively and one using no pretreatment. Results showed clear benefits in the laminaria group, in terms of achieving preoperative cervical dilatation and ease of further operative dilatation. Laminaria tents were superior to PGF2 alpha gel which was, in turn, superior to no pretreatment. There were no differences in blood loss or postoperative complications among the 3 groups. Laminaria tents provide a cheap, effective and safe method of reducing the risk of cervical damage in women undergoing surgical termination of pregnancy.     

Primary dysmenorrhoea: the importance of both prostaglandins E2 and F2α

Summary. Menstrual fluid was collected in a contraceptive diaphragm from 16 women with primary dysmenorrhoea and 12 matched control subjects without dysmenorrhoea. Prostaglandins F_2α (PGF_2α), E₂ (PGE₂) and 6-oxo-prostaglandin F_1α (6-oxo-PGF_lα) were extracted and measured using gas-chromatography: mass spectrometry (GC:MS). The concentrations of both PGF_2α and PGE₂ were higher on days 1 and 2 in the dysmenorrhoea group than in the control group and the concentration of PGF_2α was higher on day 1 than on day 2 in the dysmenorrhoea group. The concentrations of 6-oxo-PGF_1α (the stable metabolite of PGI₂) were low in both groups. These results confirm suggestions that PGF_2α is important in the aetiology of dysmenorrhoea and also indicate that PGE₂ may be involved.     

Oral Prostaglandins E2 and F2a in the Induction of Labour

Summary: Oral prostaglandins E₂ and F_2a were used to augment amniotomy in the induction of labour in 173 patients. The success rate was significantly higher with prostaglandin E₂ than with prostaglandin F_2a (89% and 75%, respectively). This was achieved despite a significantly lower incidence of gastrointestinal side effects. No serious maternal or fetal complications occurred with either drug. It is concluded that oral prostaglandin E₂ is more efficient than oral prostaglandin F_2a in the induction of labour.     

Cervical Ripening Before Induction of Labour in Patients with an Unfavourable Cervix: A Comparative Randomized Study of the Atad Ripener Device, Prostaglandin E2 Vaginal Pessary, and Prostaglandin E2 Intracervical Gel

Summary: One hundred and nineteen women with singleton pregnancy and cephalic presentation requiring induction of labour in the presence of an unfavourable cervix (Bishop score ≤ 4) were studied. Five patients were excluded because of failure to comply with the protocol. Cervical ripening was carried out using 3 different methods; 36 used the Atad Ripener Device, 39 received 0.5 mg PGE, intracervical gel and 39 received at least one 3 mg PGE₂ intravaginal pessary. There were no differences in the demographic characteristics and the indications for induction. Five patients developed complications during the ripening period necessitating intervention; 3 required emergency Caesarean section and 2 delivered vaginally. Although statistically there were no differences among the 3 methods of cervical ripening, the power of the study is probably not large enough to show the differences. The PGE₂ pessary appears to be more effective with 68% of patients either going into labour during cervical ripening or succeeding in the cervical ripening compared to around 50% in the Atad and PGE, gel groups. The vaginal delivery rate was 87.2% in the pessary group compared to 72.2% in the Atad group and 84.6% in the gel group. The duration of labour was also shorter in the pessary group with 73.5% delivered within 24 hours compared to 57.7% in the Atad group and 57.6% in the gel group. Although the results of the Atad device seem to be inferior, the risk of uterine hyperstimulation from the use of the device is probably lower than that of the PGE₂ and may therefore be preferable in women with fetuses at high risk of fetal hypoxia.     

Amniotic fluid concentrations of secreted pregnancy-associated endometrial α1 and α2-globulins (α1- and α2-PEG)

Summary. The levels of pregnancy-associated endometrial α₁- and α₂-globulins (α₁- and α₂-PEG), the two major proteins synthesized and secreted by the endometrium in vitro have been assayed in 210 amniotic fluid specimens obtained at termination of pregnancy or by amniocentesis, or at delivery. α₁-PEG was undetectable until week 10 and thereafter rose to peak levels between weeks 20 and 24. Levels fell 15-fold by week 35 but substantial amounts were still present at parturition. α₂-PEG was present at highest levels during early pregnancy, at weeks 6–15, but thereafter levels rapidly fell until during weeks 31–42 α₂-PEG was detectable in only 3 of 25 specimens. During weeks 15–20, when α₂-PEG levels fell and α₁-PEG levels rose, a high correlation was observed between the week of gestation and the log of the ratios of the concentration of these proteins. These observations provide the opportunity to assess the role of endometrial and decidual dysfunction in the aetiology of pregnancy disorders.