The great tocolytic debate: some pitfalls in the study of safety

Adverse drug reactions to tocolytic treatment for preterm labour: prospective cohort study

OBJECTIVE

To evaluate the incidence of serious maternal complications after the use of various tocolytic drugs for the treatment of preterm labour in routine clinical situations.

DESIGN

Prospective cohort study.

SETTING

28 hospitals in the Netherlands and Belgium.

PARTICIPANTS

1920 consecutive women treated with tocolytics for threatened preterm labour.

MAIN OUTCOME MEASURES

Maternal adverse events (those suspected of being causally related to treatment were considered adverse drug reactions) leading to cessation of treatment.

RESULTS

An independent panel evaluated the recorded adverse events, without knowledge of the type of tocolytic used. Of the 1920 women treated with tocolytics, 1327 received a single course of treatment (69.1%), 282 sequential courses (14.7%), and 311 combined courses (16.2%). Adverse drug reactions were categorised as serious or mild in 14 cases each. The overall incidence of serious adverse drug reaction was 0.7%. Compared with atosiban, the relative risk of an adverse drug reaction for single treatment with a beta adrenoceptor agonist was 22.0 (95% confidence interval 3.6 to 138.0) and for single treatment with a calcium antagonist was 12 (1.9 to 69). Multiple drug tocolysis led to five serious adverse drug reactions (1.6%). Multiple gestation, preterm rupture of membranes, and comorbidity were not independent risk factors for adverse drug reactions.

CONCLUSIONS

The use of beta adrenoceptor agonists or multiple tocolytics for preventing preterm birth is associated with a high incidence of serious adverse drug reactions. Indometacin and atosiban were the only drugs not associated with serious adverse drug reactions. A direct comparison of the effectiveness of nifedipine and atosiban in postponing preterm delivery is needed.

Germinal matrix-intraventricular hemorrhage in the premature newborn: management and outcome

Germinal matrix-intraventricular hemorrhage (GMH-IVH) in the premature newborn results from rupture of fragile capillaries in the germinal matrix. Its pathogenesis is multifactorial and relates principally to a pressure-passive cerebral circulation, fluctuations in cerebral blood flow, and derangements of coagulation and fragility of the germinal matrix microvasculature. Several interventions have beneficial effects for prevention of GMH-IVH. Outcome after GMH-IVH relates largely to the severity of hemorrhage, the extent of hemorrhagic and ischemic parenchymal involvement, and complications (e.g., posthemorrhagic hydrocephalus). Even in the absence of neuroimaging abnormalities, VLBW infants have a high incidence of academic and behavioral problems which persist into adolescence and early adulthood.

Methodology for the evaluation of drugs in pregnant women

Although drugs are prescribed during pregnancy with some reluctance, they fulfill a real need in some circumstances. Adequate drug evaluation is thus essential, either based on efficacy and safety or mainly safety, using available data from non-pregnant women. Evaluation methodology is not fundamentally different during pregnancy. Recommendations for drug development are formulated on the basis of the most common situations as well as specific suggestions, thus raising the awareness of the different partners participating in healthcare (institutions, the pharmaceutical industry and prescribers). In particular, regulatory and economic incentives superimposed upon those recommendations adopted in Europe and the US for orphan diseases should be put into place to assist in the evaluation of drugs used in obstetrics. Medical needs in obstetrics should be better identified, and labelling of drugs for use during pregnancy should be better directed towards prescribers; a national registry of pregnancies should be established in France.

Human chorionic gonadotropin in cervicovaginal secretions as a predictor of preterm delivery

OBJECTIVES

To determine whether human chorionic gonadotropin (hCG) detected in cervicovaginal secretions of patients with symptoms suggestive of preterm labor is a predictor of preterm birth.

METHODS

Women presenting to labor and delivery with symptoms of preterm labor were invited to participate. After collecting secretions with a cotton-tipped applicator from the posterior fornix and endocervical canal, we placed the swab in a test tube containing 1 ml of normal saline. From this solution, we performed qualitative and quantitative hCG measurements. Qualitative and quantitative hCG results from women who delivered at term were compared with those delivering prior to 37 weeks' gestation.

RESULTS

Samples were obtained and analyzed from 86 women at a mean (+/- standard deviation) gestational age of 30.7+/-2.9 weeks. Of the 86 subjects enrolled, 28 (32.6%) delivered preterm. A positive rapid qualitative assay from cervicovaginal secretions between 24 and 34 weeks' gestation was associated with a significant increase in the incidence of preterm delivery (relative risk 2.62, 95% confidence interval (CI) 1.38, 4.98). The likelihood ratios for a positive and negative test were 2.19 (95% CI 1.35, 3.56) and 0.51 (95% CI 0.30, 0.85) respectively. Using a cut-off of 19 mIU/ml, similar diagnostic accuracy for predicting preterm birth was obtained with the quantitative test 1.93 (95% CI 1.14, 3.26) and 0.62 (95% CI 0.40, 0.98).

CONCLUSIONS

Qualitative and quantitative hCG measurements from cervicovaginal secretions may be useful predictors of preterm birth in symptomatic patients. The qualitative hCG test can be used at the bedside with results obtained in minutes.

The Webster Technique: a chiropractic technique with obstetric implications

OBJECTIVE

To survey members of the International Chiropractic Pediatric Association (ICPA); regarding the use of the Webster Technique for managing the musculoskeletal causes of intrauterine constraint, which may necessitate cesarean section.

METHODS

Surveys were mailed to 1047 US and Canadian members of the ICPA.

RESULTS

One hundred eighty-seven surveys were returned from 1047 ICPA members, constituting a return rate of 17.86%. Seventy-five responses did not meet the study inclusion criteria and were excluded; 112 surveys (11%) provided the data. Of these 112 surveys, 102 (92%) resulted in resolution of the breech presentation, while 10 (9%) remained unresolved.

CONCLUSION

The surveyed doctors reported a high rate of success (82%) in relieving the musculoskeletal causes of intrauterine constraint using the Webster Technique. Although the sample size was small, the results suggest that it may be beneficial to perform the Webster Technique in month 8 of pregnancy, when breech presentation is unlikely to spontaneously convert to cephalic presentation and when external cephalic version is not an effective technique. When successful, the Webster Technique avoids the costs and/or risks of external cephalic version, cesarean section, or vaginal trial of breech.In view of these findings, the Webster Technique deserves serious consideration in the health care management of expectant mothers exhibiting adverse fetal presentation.

Preterm labour

Studies in the past year have clarified the roles of inflammatory mediators in preterm labour. Exploration of possible genetic predisposition is just beginning. Ultrasound measurement of cervical length has the potential to predict women at risk of preterm delivery several weeks before it occurs. Biochemical testing such as fetal fibronectin can possibly increase its predictive value and differentiate true preterm labour from more innocent preterm contractions. The use of antibiotics for preterm premature rupture of membranes has been clarified with the ORACLE I trial, which shows health benefits for the neonate with the use of erythromycin, whereas antibiotics do not seem to play a beneficial role in spontaneous preterm labour without evidence of clinical infection. There have been further studies suggesting that agents other than beta-agonists are preferable for acute tocolysis and that repeated doses of corticosteroids should be used with caution.