Late midtrimester medical pregnancy terminations: three different procedures with prostaglandin F2 alpha and laminaria tents

One hundred twenty eight women underwent midtrimester induced abortion with: 1) combined regimen of intramniotic prostaglandin (PG) F2a injection and intracervical laminaria tents (group A, 50 women), 2) intramniotic PGF2a injection only (group B, 51 women) and 3) laminaria tents followed by intracervical PGF2a tablets insertion (group C, 27 women). The mean induction-abortion time (+/- SE) was 24.9 +/- 1.7 hours for group A, 28.2 +/- 2.2 hours for group B (p greater than 0.05) and 42.1 +/- 3.4 hours for group C, significantly longer than goup A and B (p less than 0.001 and p less than 0.01 respectively). In 48 hours 98% of the patients of group A, 90% of group B (p less than 0.05) and 59% of group C (p less than 0.001) completed the abortion procedure. Parous women of group A and B presented similar induction - abortion time, while in nulliparous the use of laminaria shortened the abortion procedure significantly (p less than 0.05). The complications rate was low. In conclusion, the intracervical PGF2a insertion is a simple but very slow abortion procedure with high failure rates. The intramniotic PGF2a injection is a successful method for late midtrimester medical pregnancy termination and the concurrent use of laminaria tents shortens the abortion procedure, particularly in nulliparous, reduces the number of prostaglandins' reinjections and increases the incidence of successful abortion within 48 hours.     

Laminaria augmentation of intra-amniotic PGF2α for midtrimester pregnancy termination

In our hands, intra-amniotic PGF₂α 40 mg for midtrimester pregnancy termination had a mean infusion to abortion interval of 29.4 hr. However, pretreatment of 230 patients with laminaria tents inserted 14–18 hr before PGF₂α infusion resulted in a dramatically reduced time to abortion (14.3 hr mean) with a low incidence of gastrointestinal and other side effects. Laminaria tents inserted at the same time as PGF₂α infusion in 26 patients also resulted in reduced time to abortion (18.6 hr mean). In the laminaria pretreated group, the infusion to abortion interval was indirectly related to the number of laminaria inserted and not to the nulliparous or parous state. Although we have made significant strides in shortening the abortion interval in the hospital, retained placentae and blood loss persist as problems related to the use of prostaglandin for abortion.     

Laminaria augmentation of intra-amniotic PGF2 for midtrimester pregnancy termination

In our hands, intra-amniotic PGF_2^α 40 mg for midtrimester pregnancy termination had a mean infusion to abortion interval of 29.4 hr. However, pretreatment of 230 patients with laminaria tents inserted 14–18 hr before PGF_2^α infusion resulted in a dramatically reduced time to abortion (14.3 hr mean) with a low incidence of gastrointestinal and other side effects. Laminaria tents inserted at the same time as PGF_2^α infusion in 26 patients also resulted in reduced time to abortion (18.6 hr mean). In the laminaria pretreated group, the infusion to abortion interval was indirectly related to the number of laminaria inserted and not to the nulliparous or parous state. Although we have made significant strides in shortening the abortion interval in the hospital, retained placentae and blood loss persist as problems related to the use of prostaglandin for abortion.     

Termination of second trimester pregnancy with laminaria and intramuscular 16 phenoxy-ω-17,18,19,20 tetranor PGE2 methylsuldonylamide (sulprostone) — A randomised study

16 phenoxy-ω-17,18,19,20 tetranor PGE₂ methylsulfonylamide (Sulprostone) was used for termination of second trimester pregnancy in four groups of 30 patients. The drug was administered in intramuscular doses of either 0.5 mg four hourly or 1.0 mg 8 hourly. In two groups of 30 patients a medium size sterile laminaria was inserted into the cervical canal eight hours before the start of prostaglandin treatment. In the group treated with 1.0 mg sulprostone eight hourly, 96.7% of those with laminaria and 86.7% without laminaria aborted in respective mean times of 11.2 hrs and 17.5 hrs. All 30 patients (100%) in the laminaria group treated with 0.5 mg sulprostone four hourly aborted within 30 hours in a mean time of 10.4 hours compared with 26 patients (86.7%) in a mean time of 16.7 hours in the group without laminaria.One patient receiving 0.5 mg sulprostone four hourly (no laminaria) sustained a cervical tear requiring repair. The incidence of nausea, vomiting, diarrhoea, cold and shivering was low and similar in the four groups.     

Letter: On the administration of prostaglandins as a pre-operative means of cervical dilatation

Prostaglandin (PG) administration by the intramuscular or extraamniotic route has been reported to be a safe and reliable means of effecting cervical dilatation prior to 1st trimester abortion by suction curettage. At the Mulago Hospital, Kampala, a minimum of 5 cases of 1st trimester abortions were performed weekly using the Karman cannula (KC), a flexible polyethylene catheter which lessens the risk of cervical dilatation. In none of the cases was cervical dilatation required for insertion of a KC of sufficient diameter. Paracervical block with procaine 2% (10 ml) was used for analgesia; in rare cases, 10 mg of diazepan was administered orally or intravenously as a preoperative medication. Complications encountered included: 1) perforation of the uterine fundus; 2) metritis; and 3) retained products of conception. With proper instrumentation, cervical dilatation is no longer required for 1st trimester abortions. PG administered for cervical dilatation is no longer justified because it is time consuming, a source of additional expense, inconvenient, and is associated with uterine cramps and gastrointestinal side effects. In occasional cases, as in undue cervical resistance, the use of PGs may be justified.     

Partograms and Nomograms of Cervical Dilatation in Management of Primigravid Labour

Philpott''s graphic labour has been modified and used in 15,000 labours; it has been unanimously accepted by the staff. A nomogram has been constructed to show the normal progressive dilatation of the cervix for primigravidae admitted at different stages of cervical dilatation. Retrospective evaluation of the nomogram showed that it can separate normal labour from labour destined to result in an abnormal outcome, such as longer first and second stages, a greater incidence of instrumental delivery, and babies with low Apgar scores.It is suggested that the use of a stencil representing normal labour progress, together with Philpott''s partogram, will be of considerable use, both in specialist and in general-practitioner units.     

Prostaglandin release from human cervical tissue in the first trimester of pregnancy after preoperative dilatation with hygroscopic tents

Preoperative dilatation with hygroscopic tents before first trimester abortion by vacuum aspiration is widely accepted and reduces the risk of early and late complications. A softening effect and a reduced compliance to mechanical dilatation occurs in addition to pure mechanical dilatation of the cervix. If this softening is an effect of local prostaglandin release, however, is unknown. Prostaglandin (PG) release in vitro from cervical biopsies following dilatation in vivo by a synthetic hygroscopic tent (Dilapan) for periods of 4 h and 18 h was compared with that of biopsies from untreated women. No difference was observed between the release of PGE₂, PGF_2α, or 6-keto-PGF_1α. No significant difference was found in the tissue water content between treated and untreated women (83.8% versus 83.2%). Prostaglandins were also extracted from an alternative cervical dilator, Lamicel (a polyvinyl sponge impregnated with magnesium sulfate), and compared with the corresponding values from women pretreated with the cyclooxygenase inhibitor indomethacin before application of the tent. Significantly higher concentrations of PGE₂ and PGF_2α but not of 6-keto-PGF_1α were found in women who had not been indomethacin-treated compared with indomethacin-treated women. Slices of the cervix from non-pregnant women operated upon for benign conditions were divided into an outer stromal layer and an inner layer, including the mucosa, and the PG-release in vitro was measured. The inner layer of the cervix showed a significantly higher release of PGE₂ and PGF_2α compared with the outer layer. Lamicel treatment before first trimester abortion results in a significant dilatation of the cervix and a reduced complaince to mechanical dilatation, and this study supports the hypothesis that this effect is mediated via a local PG-release from the cervix. It seems reasonable to believe that Dilapan treatment too has the capacity to induce PG-release from the cervix, but this could not be demonstrated in this study, probably because needle biopsies taken mainly from the outer cervical layers were analyzed.     

The use of prostaglandin pessaries prior to vaginal termination

Prosaglandin F2alpha 100 mg pessaries were inserted on 2 occasions within 24 hours of vaginal termination of pregnancy in an attempt to facilitate the subsequent operative procedure. Some degree of cervical dilatation occurred in 8 out of the 10 subjects studied but in only multiparous patients was it of sufficient degree to make evacuation easier. Side effects of uterine cramps, a flushed sensation; and the presence of diarrhea were relatively common. Disadvantages of prostaglandin F2a pessaries for use in vaginal termination of pre.g.nancy (e.g., large amounts are needed to induce cervical dilatation; cervical trauma is affected by parity status, no local specific ccervical softening action) preclude its clinical use.     

Distension of the uterus induces HspB1 expression in rat uterine smooth muscle

The uterine musculature, or myometrium, demonstrates tremendous plasticity during pregnancy under the influences of the endocrine environment and mechanical stresses. Expression of the small stress protein heat shock protein B1 (HspB1) has been reported to increase dramatically during late pregnancy, a period marked by myometrial hypertrophy caused by fetal growth-induced uterine distension. Thus, using unilaterally pregnant rat models and ovariectomized nonpregnant rats with uteri containing laminaria tents to induce uterine distension, we examined the effect of uterine distension on myometrial HspB1 expression. In unilaterally pregnant rats, HspB1 mRNA and Ser(15)-phosphorylated HspB1 (pSer(15) HspB1) protein expression were significantly elevated in distended gravid uterine horns at days 19 and 23 (labor) of gestation compared with nongravid horns. Similarly, pSer(15) HspB1 protein in situ was only readily detectable in the distended horns compared with the nongravid horns at days 19 and 23; however, pSer(15) HspB1 was primarily detectable in situ at day 19 in membrane-associated regions, while it had primarily a cytoplasmic localization in myometrial cells at day 23. HspB1 mRNA and pSer(15) HspB1 protein expression were also markedly increased in ovariectomized nonpregnant rat myometrium distended for 24 h with laminaria tents compared with empty horns. Therefore, uterine distension plays a major role in the stimulation of myometrial HspB1 expression, and increased expression of this small stress protein could be a mechanoadaptive response to the increasing uterine distension that occurs during pregnancy.     

Clinical effects and cervical tissue changes after treatment with 16,16 dimethyl-trans delta 2 PGE1 methylester in the first trimester

Cervagem pessaries, containing 1 mg of 16,16-dimethyl-trans delta 2-PGE1 methylester, was administered in the posterior vaginal fornix 4 h before vacuum aspiration in the 1st trimester. The effects of cervical dilatation, cervical collagen metabolism and cervical smooth muscle activity were investigated. In treated women the mean cervical dilatation was 7.9 mm as compared with 3.9 mm in controls. The in vitro incorporation of 14C proline in cervical tissue as well as the hydrolytic activity against a synthetic "collagen-like" polypeptide was increased after treatment with cervagem. The cervical smooth muscle sensitivity to prostaglandins, as revealed by inhibition of muscle activity, was higher in treated women than in controls. It is concluded that cervical dilatation, as induced by cervagem, involves an adaptation of both connective tissue and smooth muscle components.     

The Indications for Dilatation and Curettage

Historical aspects of dilatation and curettage are discussed and the indications reviewed for this procedure in three major age-groups: (1) childhood and adolescence, (2) maturity and reproductive period, (3) menopause and post-menopause. As the most frequently performed obstetrical and gynecological procedure, it is not an innocuous operation, and clear-cut indications for its use are presented with reference to abnormal vaginal bleeding in all age groups, infertility, functional ovarian tumours, neoplasia of the uterus, cervical biopsy, and major pelvic surgery. It is concluded that dilatation and curettage has a major place in the diagnostic and the therapeutic armamentarium of the thorough obstetrician and gynecologist.     

Convergence in tent architecture and tent-making behavior among neotropical and paleotropical bats

Fifteen species of neotropical and three species of paleotropical bats are known either to roost in or to make tents in over 80 species of vascular plants. We summarize the current knowledge of bat-tent architecture, report two new styles of tents (conical and apical) from the Paleotropics, compare the similarity in tents constructed, or used, by neotropical and paleotropical bats, and consider possible functions of tents. Seven styles of tents are known from the Neotropics, three (conical, palmate umbrella, and apical tents) are known from both the Neo- and the Paleotropics, and one (stem tent) is unique to the Paleotropics. In the Neotropics tent-roosting and/or tent-making appears to be a behavior unique to the diverse microchiropteran family Phyllostomidae (subfamily Phyllostomatinae: tribe Stenodermatini), and in the Paleotropics two members of the megachiropteran family Pteropodidae and one member of the microchiropteran family Vespertilionidae are known to construct or roost in tents. Despite the variety of plant taxa used by bats in tent construction, there appears to be a limited number of different leaf forms that can be altered by bats and used as tents. We suggest that the similarity in tent architecture observed among the neotropical and paleotropical bats is a consequence of convergence in leaf morphology among forest understory plants. The congruence in tent-making/roosting behavior observed in members of the Stenodermatini and the Pteropodidae (genusCynopterus) suggests a phylogenetic influence on these behaviors. The similarity in tent-making and/or tent-roosting behavior and life-history traits (small, <70 g, mostly foliage-roosting frugivores) among these divergent neotropical and paleotropical taxa supports a convergence hypothesis in which members of these groups have become ecological equivalents. Although actual tent-making has been observed in only one bat species to date, we suggest that the principal selective force leading to the evolution of tent-making is a polygynous mating system whereby males construct tents to gain access to females. Tents in turn provide resources that offer protection from predators and inclement weather.     

Clinical effects and cervical tissue changes after treatment with 16, 16 dimethyl-trans Δ2 PGE1 methylester in the first trimester

Cervagem pessaries, containing 1 mg of 16, 16-dimethyl-trans Δ 2-PGE₁ methylester, was administered in the posterior vaginal fornix 4 h before vacuum aspiration in the 1st trimester. The effects of cervical dilatation, cervical collagen metabolism and cervical smooth muscle activity were investigated. In treated women the mean cervical dilatation was 7.9 mm as compared with 3.9 mm in controls. The in vitro incorporation of 14C proline in cervical tissue as well as the hydrolytic activity against a synthetic “collagen-like” polypeptide was increased after treatment with cervagem. The cervical smooth muscle sensitivity to prostaglandins, as revealed by inhibition of muscle activity, was higher in treated women than in controls. It is concluded that cervical dilatation, as induced by cervagem, involves an adaptation of both connective tissue and smooth muscle components.     

Roosting Ecology of the Tent‐Roosting Bat Artibeus watsoni (Chiroptera: Phyllostomidae) in Southwestern Costa Rica1

We described the plants used as roost resources by Artibeus watsoni in southwestern Costa Rica, assessed roost fidelity, and compared roosting ecology between two sites, Golfito and Corcovado, which vary in the degree of human influence. A total of 349 tents from 25 different plant species were used by A. watsoni as roosts; some plant species (e.g., Carludovica palmata, Asplundia alata, Heliconia imbricata and Calathea lutea) were modified into tents with significantly higher frequency than others. The highest tents above the ground were observed in Philodendron popenoei and Rhodospatha wendlandii, whereas tents in Philodendron grandipes and A. alata were significantly lower than any other species. Asplundia alata and R. wendlandii also had the highest frequency of leaves modified per plant. Fidelity of bats to tents was low, although bats used several tents intermittently within a restricted area. Males generally were more faithful to tents than females, although not significantly so. This observation, along with indirect evidence of leaf modification, suggests that males are primarily responsible for tent construction. The two study sites differed in the plants used for roosting and in tent fidelity. Bats in Corcovado used a greater variety of plant species for tent roosting, whereas bats in Golfito were more faithful, suggesting that roosting resources were scarcer at the latter site.     

The dynamics of tent‐roosts in the palm Sabal mauritiiformis and their use by bats in a montane dry forest

Tent‐making bats modify leaves to build refuges. Leaf modification involves energetic and defense costs that should be balanced by the benefits of tent‐roosting. The alteration of the leaf's vascular system reduces the tent's life expectancy, so to obtain a benefit, bats are expected to use tents regularly as long as they remain functional and not modify more leaves than necessary. Over 2 yr, we documented the dynamics of tent construction and use by Uroderma convexum and other bat species in the palm Sabal mauritiiformis in a Colombian transitional dry forest. We also assessed tent condition and compared it to nonmodified leaves of approximately the same age in focal palms. Probability of tent use by U. convexum varied between 57 percent during a reproductive period and 4 percent outside of this period. Bats cut the main vein of folioles, partially affecting water transport in the leaf. However, there were no differences between tents and nonmodified leaves in deterioration scores or deterioration rates over 1 yr. During 2 yr, 48 tents were lost for different causes, but this loss was balanced by the construction of 51 new tents. Thus, bats maintained an excess of usable tents. Palm leaves are long‐lived and seem preadapted to sustain damage and remain viable, particularly in species growing in dry environments. We present several hypotheses to explain the advantage of maintaining a tent surplus.     

Tent selection, roosting ecology and social organization of the tent-making bat, Ectophylla alba, in Costa Rica

Small groups of the tent-making bat, Ectophylla alba , were found roosting in Heliconia (Musaceae) tents in old secondary-growth forest in north-eastern Costa Rica. The choice of specific Heliconia leaves for tents was predicted on the basis of leaf size and age. Additionally, tents in shrubs, saplings and epiphytic plants were found scattered throughout both primary- and secondary-growth forest. Tents were used either as night feeding roosts or as day-roosts for as long as 45 days. Groups of bats remained together when they moved to newly cut tents. After parturition, tent groups divided into all-male colonies and maternity colonies with females, non-volant young and a single adult male.     

Transitional forms of the cervical and first ribs]

The upper ribs possessing the signs of both cervical and first ribs (such as the size, conjunction with the sternum, dilatation of the superior intercostal spaces, double width and others) are the intermediate forms. Small dimension fluorography of 400.000 humans with roentgenographical control has revealed 468 persons with transitional forms of cervical and first ribs (0,12%), i. e. one case per 800 humans at an average. Transitional forms of cervical and first ribs can be grouped as follows: asymmetry of clavicles, asymmetry of the upper ribs, close position of the upper ribs, double width of the first ribs, conjunction of the cervical and first ribs at the vertebrum.     

Ultrasonic cervimetry to study the dilatation of the caudal cervix of the cow at parturition

The objective of this study was to investigate the temporal changes in dilatation of the caudal cervix during induced calvings (n = 5). We used ultrasound cervimetry, allowing the continuous recording of the distance between a transmitting and receiving ultrasound crystal, which were implanted opposite to each other on the caudal rim of the cervix. We started recording between 19 and 21 h after injecting a prostaglandin analogue (PG) on day 272 of gestation. A fluid-filled catheter had been introduced transcervically between the fetal membranes and the uterine wall for measurements of intra-uterine pressure (IUP). While the characteristics of calving varied widely between the five animals, it appeared possible to divide the process of dilatation into four phases. During the latent phase, which lasted until 25-43 h after PG, no net gain in dilatation occurred. We found an acceleration phase (4.3-6.8 h), in which the dilatation rate speeds up (0.49-0.84 cm/h) in three of the cows. During the phase of maximum slope (lasting 0.5-4.8 h), we measured an even higher rate (1.47-8.48 cm/h), decreasing again during the deceleration phase (rate 0.24-2.28 cm/h) in four cows. The quality of the IUP measurements precluded us from continuously investigating the relationship between cervical dilatation and uterine contractions. However, short term simultaneous recordings revealed that the cervical opening changed momentarily in the absence of IUP during the latent phase, while during the phase of maximum slope, temporary changes of dilatation coincided with uterine contractions. We concluded that the method of ultrasound cervimetry used in this study provides a valuable way to study the process of cervical dilatation in parturient cows in vivo.     

Cervical diameter after suction termination of pregnancy.

The diameter of the internal cervical os was measured in several groups of patients in an attempt to assess any damage caused by suction termination of pregnancy. Pregnant women who had had a previous abortion by vacuum aspiration had significantly greater cervical diameters than those who had not, and there was a statistically significant correlation between dilatation of the cervix at operation and cervical diameter at six weeks'' follow-up. Cervical dilatation to 10 mm or less was subsequently associated with a normal cervical diameter, but the diameter was often large when the extent of dilatation was greater than 12 mm or not known. Cervical dilatation at termination of pregnancy should, if possible not exceed 10 mm.     

Vaginally administered PGF2alpha for cervical dilatation in nulliparas prior to suction curettage

Because of the need for an atraumatic method to dilate the cervix when performing artificial abortion by suction curettage, cervical dilatation following vaginally administered PGF2alpha was studied. A 50 mg PGF2alpha vaginal suppository was administered to 40 (treated group) first trimester nulliparas 3 hours prior to progressive cervical dilatation from a 19 (circumference in mm) Pratt dilator to a 35 Pratt dialator. The smallest-sized dilator that met resistance was interpreted as being the amount of clinically significant cervical dilatation. The results were compared to 20 (control group) first trimester nulliparas who received no PGF2alpha studied in an identical manner. Independent of gestational age, treated patients were dilated significantly more than the control patients. When subjects of similar gestational age were compared, PGF2alpha treated subjects were more often dilated sufficiently to perform abortion (55%) by suction curettage than control group subjects (5%). Those PGF2alpha subjects needing further dilatation to accept an appropriate sized cannula for their gestational age needed less dilatation than did those subjects of similar gestational age in the control group. No serious complications of PGF2alpha per se were observed and the most frequent side effects, vomiting and diarrhea, did not appear severe enough to limit the clinical practicability of the method.