Jane Thomas

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUNDnProstaglandins have been used for induction of labour since the 1960s. This is one of a series of reviews evaluating methods of induction of labour. This review focuses on prostaglandins given per vaginam, evaluating these in comparison with placebo (or expectant management) and with each other; prostaglandins (PGE2 and PGF2a); different formulations (gels, tablets, pessaries) and doses.nnnOBJECTIVESnTo determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).nnnSEARCH METHODSnWe searched the Cochrane Pregnancy and Childbirth Groups Trials Register (1 March 2014) and bibliographies of relevant papers.nnnSELECTION CRITERIAnClinical trials comparing vaginal prostaglandins used for third trimester cervical ripening or labour induction with placebo/no treatment, with each other, or other methods listed above it on a predefined list of labour induction methods.nnnDATA COLLECTION AND ANALYSISnWe assessed studies and extracted data independently.nnnMAIN RESULTSnSeventy randomised controlled trials (RCTs) (11,487 women) are included. In this update seven new RCTs (778 women) have been added. Two of these new trials compare PGE2 with no treatment, four compare different PGE2 formulations (gels versus tablets, or sustained release pessaries) and one trial compares PGF2a with placebo. The majority of trials were at unclear risk of bias for most domains.Overall, vaginal prostaglandin E2 compared with placebo or no treatment probably reduces the likelihood of vaginal delivery not being achieved within 24 hours. The risk of uterine hyperstimulation with fetal heart rate changes is increased (4.8% versus 1.0%, risk ratio (RR) 3.16, 95% confidence interval (CI) 1.67 to 5.98, 15 trials, 1359 women). The caesarean section rate is probably reduced by about 10% (13.5% versus 14.8%, RR 0.91, 95% CI 0.81 to 1.02, 36 trials, 6599 women). The overall effect on improving maternal and fetal outcomes (across a variety of measures) is uncertain.PGE2 tablets, gels and pessaries (including sustained release preparations) appear to be as effective as each other, small differences are detected between some outcomes, but these maybe due to chance.nnnAUTHORS CONCLUSIONSnProstaglandins PGE2 probably increase the chance of vaginal delivery in 24 hours, they increase uterine hyperstimulation with fetal heart changes but do not effect or may reduce caesarean section rates. They increase the likelihood of cervical change, with no increase in operative delivery rates. PGE2 tablets, gels and pessaries appear to be as effective as each other, any differences between formulations are marginal but may be important.

How much variation in CS rates can be explained by case mix differences

Objectiveu2003 To quantify the amount of variation in caesarean section (CS) rates between maternity units explained by case mix differences.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis

BACKGROUNDnAspiration pneumonitis is a syndrome resulting from the inhalation of gastric contents. The incidence in obstetric anaesthesia has fallen, largely due to improved anaesthetic techniques and the increased use of regional anaesthesia at caesarean section. However, aspiration pneumonitis is still a cause of maternal morbidity and mortality, and it is important to use effective prophylaxis.nnnOBJECTIVESnTo determine whether interventions given prior to caesarean section reduce the risk of aspiration pneumonitis in women with an uncomplicated pregnancy.nnnSEARCH METHODSnWe searched the Cochrane Pregnancy and Childbirth Groups Trials Register (30 April 2013).nnnSELECTION CRITERIAnRandomised controlled trials were included. Quasi-randomised trials were excluded.nnnDATA COLLECTION AND ANALYSISnReview authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. Fixed-effect meta-analysis was used to combine data where it was reasonable to assume that studies were estimating the same underlying treatment effect. If substantial clinical or statistical heterogeneity was detected, we used random-effects analysis to produce an overall summary.nnnMAIN RESULTSnThirty-two studies were included in this review. However, only 22 studies, involving 2658 women, provided data for analysis. All the women in the included studies had a caesarean section under general anaesthesia. The studies covered a number of comparisons, but were mostly small and of unclear or poor quality.When compared with no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09 to 0.32, two studies, 108 women), H2 antagonists (RR 0.09, 95% CI 0.05 to 0.18, two studies, 170 women) and proton pump antagonists (RR 0.26, 95% CI 0.14 to 0.46, one study 80 women). H2 antagonists were associated with a reduced the risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists (RR 0.39, 95% CI 0.16 to 0.97, one study, 120 women), but compared with antacids the findings were unclear. The combined use of antacids plus H2 antagonists was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo (RR 0.02, 95% CI 0.00 to 0.15, one study, 89 women) or compared with antacids alone (RR 0.12, 95% CI 0.02 to 0.92, one study, 119 women).nnnAUTHORS CONCLUSIONSnThe quality of the evidence was poor, but the findings suggest that the combination of antacids plus H2 antagonists was more effective than no intervention, and superior to antacids alone in preventing low gastric pH. However, none of the studies assessed potential adverse effects or substantive clinical outcomes. These findings are relevant for all women undergoing caesarean section under general anaesthesia.

Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section

BACKGROUNDnNausea and vomiting are distressing symptoms which are experienced commonly during caesarean section under regional anaesthesia and can also occur in the period following the procedure.xa0nnnOBJECTIVESnTo assess the efficacy of pharmacological and non-pharmacological interventions given prophylactically to prevent nausea and vomiting in women undergoing regional anaesthesia for caesarean section.nnnSEARCH METHODSnWe searched the Cochrane Pregnancy and Childbirth Groups Trials Register (27 February 2012) and reference lists of identified studies.nnnSELECTION CRITERIAnWe included randomised controlled trials (RCTs) and excluded quasi-RCTs and cross-over studies.nnnDATA COLLECTION AND ANALYSISnReview authors independently assessed the studies for inclusion, assessed risk of bias and carried out data extraction. Data entry was checked. xa0nnnMAIN RESULTSnFifty-two studies met the inclusion criteria but only 41 studies, involving 5046 women, provided useable data for the review involving women having caesareans under regional anaesthesia. The majority of the studies involved women undergoing elective caesarean section. Only two studies included emergency surgery, however, they did not stratify data according to type of surgery. The studies covered numerous comparisons, but the majority of studies involved 5-HT(3) receptor antagonists, dopamine receptor antagonists, corticosteroids or acupressure. Studies were mainly small and of unclear quality.Three classes of intervention were found to be effective in at least three out of four of our primary outcomes (intraoperative nausea, intraoperative vomiting, postoperative nausea and postoperative vomiting). These interventions were 5-HT(3) antagonists, dopamine antagonists and sedatives. Other classes of intervention were effective for fewer than three of our primary outcomes.With 5-HT antagonists, we found a reduction in intraoperative nausea (average risk ratio (RR) 0.64, 95% confidence interval (CI) 0.46 to 0.88, eight studies, 720 women). There were also reductions in postoperative nausea (average RR 0.40, 95% CI 0.25 to 0.64, four studies, 405 women) and vomiting (average RR 0.50, 95% CI 0.32 to 0.77, five studies, 565 women). We did not detect a significant reduction in intraoperative vomiting (average RR 0.56, 95% CI 0.31 to 1.00, seven studies, 668 women).Dopamine antagonists demonstrated a reduction in intraoperative nausea (average RR 0.38, 95% CI 0.25 to 0.57, nine studies, 636 women) and intraoperative vomiting (average 0.39, 95% CI 0.24 to 0.64, eight studies, 536 women), with similar reductions in postoperative nausea (average RR 0.60, 95% CI 0.40 to 0.91, five studies, 412 women) and vomiting (average RR 0.57, 95% CI 0.36 to 0.91, six studies, 472 women). These differences were observed with both metoclopramide and droperidol.Sedatives (most commonly propofol) demonstrated a reduction in intraoperative nausea (average RR 0.71, 95% CI 0.52 to 0.96, four studies, 285 women) and intraoperative vomiting (average RR 0.42, 95% CI 0.26 to 0.68, four studies, 285 women), also with a reduction in postoperative nausea (average RR 0.25, 95% CI 0.09 to 0.71, two studies 145 women) and vomiting (average RR 0.09, 95% CI 0.03 to 0.28, two studies, 145 women).Acupressure was found to be effective for intraoperative nausea (average RR 0.59, 95% CI 0.38 to 0.90, six studies, 649 women) but not postoperative nausea (average RR 0.83, 95% CI 0.68 to 1.00, three studies, 429 women). Acupressure was not effective at reducing vomiting either intraoperatively (average RR 0.74, 95% CI 0.46 to 1.18, six studies, 649 women) or postoperatively (average RR 0.69, 95% CI 0.45 to 1.06, three studies, 429 women).Other effective intervention classes included corticosteroids, antihistamines, and anticholinergics.There were insufficient data to demonstrate any class of intervention was superior to another. There were no significant differences observed in the comparison of combined versus single interventions.Few studies assessed our secondary outcomes or the incidence of adverse effects. However, one study showed an increase in respiratory depression with sedation (midazolam) compared with dopamine antagonists.nnnAUTHORS CONCLUSIONSnThis review indicates that many different interventions have efficacy in preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. There is little evidence that combinations of treatment are better than single agents.

Hyaluronidase for cervical priming and induction of labour.

BACKGROUNDnDilatation and effacement of the cervix are not only a result of uterine contractions, but are also dependent upon ripening processes within the cervix. The cervix is a fibrous organ composed principally of hyaluronic acid, collagen and proteoglycan. Hyaluronic acid increases as pregnancy progresses, increases markedly after the onset of labour and decreases rapidly after birth of the infant. An increase in the level of hyaluronic acid is associated with an increase in tissue water content. Cervical ripening during labour is characterised by changes of the cervix with softening of the tissue and an increased water content. Cervical injection of hyaluronidase was postulated to increase cervical ripening. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.nnnOBJECTIVESnTo determine the effects of hyaluronidase for third trimester cervical ripening or induction of labour in comparison with other methods of induction of labournnnSEARCH STRATEGYnThe Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000.nnnSELECTION CRITERIAn(1) clinical trials comparing hyaluronidase used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.nnnDATA COLLECTION AND ANALYSISnA strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involves a two-stage method of data extraction.nnnMAIN RESULTSnThere were no included trials.nnnREVIEWERS CONCLUSIONSnThe role of hyaluronidase as a method of cervical priming or induction of labour is uncertain.

An audit of the management of induced abortion in England and Wales

Objectives: To assess the quality of care provided to women undergoing induced abortion. Methods: The design was a single round audit questionnaire aimed at the providers of abortion services throughout England and Wales (NHS hospitals, clinics under NHS, agency agreements and private units. The levels of care were assessed against agreed audit criteria. Results: Responses were received from 240 (74%) of the 324 units providing abortion care in England and Wales. These units undertook 80% of the 176 000 termination procedures. Generally standards of care were appropriate, but there were clear areas for improvement including choice of method, infection screening, and delays in referral. A number of unnecessary investigations were still evident, including cross‐matching, while lower doses and alternative drug regimens might reduce costs. Only half of the units audited procedures and complications. Conclusions: This audit was carried out prior to the publication of the RCOG evidence‐based guideline and a further round of audit to assess the impact of the guideline should now be considered.

Interventions at caesarean section for reducing the risk of aspiration pneumonitis.

BACKGROUNDnVarious interventions are used as prophylaxis for aspiration pneumonitis in obstetric anaesthesia. This review, based on a Cochrane systematic review currently being updated, examines whether interventions given before caesarean section reduce the risk of aspiration pneumonitis.nnnMETHODSnTwenty-two studies, involving 2658 women providing data in a usable format for meta-analysis were identified.nnnRESULTSnCompared to no treatment or placebo, there was a significant reduction in the risk of intra-gastric pH <2.5 with antacids (risk ratio (RR) 0.17, 95% confidence interval (CI) 0.09-0.32), H2 antagonists (RR 0.09, 95% CI 0.05-0.18) and proton-pump antagonists (RR 0.26, 95% CI 0.14-0.46). H2 antagonists were associated with a reduced risk of intra-gastric pH <2.5 when compared with proton-pump antagonists (RR 0.39, 95% CI 0.16-0.97), but compared with antacids the findings were unclear. Combined use of antacids plus H2 antagonists was associated with a significant reduction in the risk of intra-gastric pH <2.5 when compared with placebo (RR 0.02, 95% CI 0.00-0.15) or compared with antacids alone (RR 0.12, 95% CI 0.02-0.92).nnnCONCLUSIONnThe quality of evidence was weak and may not reflect a reduction in the risk of aspiration pneumonitis since none of the studies assessed substantive clinical outcomes or potential adverse effects. Further work is required to validate the suitability of surrogate markers of pH and gastric volume for clinical outcomes in the context of aspiration pneumonitis.

Antenatal breast examination for promoting breastfeeding

BACKGROUNDnThe rationale for antenatal breast examination has included the need to determine whether any problems with breastfeeding could be anticipated, using the time during examination as an opportunity for the healthcare provider to introduce and discuss the importance of breastfeeding, and for the detection of breast cancer during pregnancy. Despite these purported benefits of antenatal breast examination, whether there is evidence that it should be recommended for all pregnant women remains unclear.nnnOBJECTIVESnTo determine the effect of antenatal breast examination(s) on the initiation of breastfeeding.nnnSEARCH STRATEGYnWe searched the Cochrane Pregnancy and Childbirth Groups Trials Register (March 2008).nnnSELECTION CRITERIAnAll randomised controlled trials of the effects of antenatal breast examination, with a concurrent comparison group.nnnDATA COLLECTION AND ANALYSISnTwo review authors independently assessed trial quality and extracted data.nnnMAIN RESULTSnWe identified no randomised controlled trials.nnnAUTHORS CONCLUSIONSnIdeally, policies that govern the care of pregnant women should be evidence based. There is no doubt that breastfeeding is beneficial for both mother and infant. However, there is no evidence to support the notion that antenatal breast examinations are effective in promoting breastfeeding, nor any evidence on other potential effects of antenatal breast examination, such as the detection of breast anomalies or satisfaction with care.

Corticosteroids for induction of labour.

BACKGROUNDnThe role of corticosteroids in the process of labour is not well understood. Animal studies have shown the importance of cortisol secretion by the fetal adrenal gland in initiating labour in sheep. Infusion of glucocorticosteroids into the fetus has also shown to induce premature labour in sheep. Some assumptions have been proposed regarding the mode of action of corticosteroids, including both a paracrine and autocrine action, following the identification of glucocorticoid receptors on human amnion. Given these studies it has been postulated that corticosteroids given intraamniotically will promote the induction of labour. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.nnnOBJECTIVESnTo determine the effects of corticosteroids for third trimester cervical ripening or induction of labour in comparison with other methods of cervical priming or induction of labour.nnnSEARCH STRATEGYnThe Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and bibliographies of relevant papers. Last searched: November 2000.nnnSELECTION CRITERIAn(1) clinical trials comparing corticosteroids used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.nnnDATA COLLECTION AND ANALYSISnA strategy has been developed to deal with the large volume and complexity of trial data relating to labour induction. This involves a two-stage method of data extraction.nnnMAIN RESULTSnThere are no included trials, hence no results are presented.nnnREVIEWERS CONCLUSIONSnThe effectiveness of corticosteroids for induction of labour is uncertain. Use of this method of induction of labour is not commonly used and further research in this area is probably unwarranted.