Amnioinfusion for meconium-stained liquor in labour

Meconium Aspiration Syndrome: A Narrative Review

Meconium aspiration syndrome is a clinical condition characterized by respiratory failure occurring in neonates born through meconium-stained amniotic fluid. Worldwide, the incidence has declined in developed countries thanks to improved obstetric practices and perinatal care while challenges persist in developing countries. Despite the improved survival rate over the last decades, long-term morbidity among survivors remains a major concern. Since the 1960s, relevant changes have occurred in the perinatal and postnatal management of such patients but the most appropriate approach is still a matter of debate. This review offers an updated overview of the epidemiology, etiopathogenesis, diagnosis, management and prognosis of infants with meconium aspiration syndrome.

Antenatal and intrapartum interventions for reducing caesarean section, promoting vaginal birth, and reducing fear of childbirth: An overview of systematic reviews

Concern has been expressed globally over rising caesarean birth rates. Recently, the International Federation of Gynaecology and Obstetrics (FIGO) called for help from governmental bodies, professional organisations, women’s groups, and other stakeholders to reduce unnecessary caesareans. As part of a wider research initiative, we conducted an overview of systematic reviews of antenatal and intrapartum interventions, and reports of evidence based recommendations, to identify and highlight those that have been shown to be effective for reducing caesarean birth, promoting vaginal birth and reducing fear of childbirth. Following registration of the review protocol, (PROSPERO 2018 CRD42018090681), we searched The Cochrane Database of Systematic Reviews, PubMed, CINAHL and EMBASE (Jan 2000-Jan 2018) and searched for grey literature in PROSPERO, and on websites of health professional and other relevant bodies. Screening and selection of reviews, quality appraisal using AMSTAR-2, and data extraction were performed independently by pairs of at least two reviewers. Excluding reviews assessed as ‘critically low’ on AMSTAR-2 (n = 54), 101 systematic reviews, and 10 reports of evidence based recommendations were included in the overview. Narrative synthesis was performed, due to heterogeneity of review methodology and topics. The results highlight twenty-five interventions, across 17 reviews, that reduced the risk of caesarean, nine interventions across eight reviews that increased the risk of caesarean, eight interventions that reduced instrumental vaginal birth, four interventions that increased spontaneous vaginal birth, and two interventions that reduced fear of childbirth. This overview of reviews identifies and highlights interventions that have been shown to be effective for reducing caesarean birth, promoting vaginal births and reducing fear of childbirth. In recognising that clinical practices change over time, this overview includes reviews published from 2000 onwards only, thus providing contemporary evidence, and a valuable resource for clinicians when making decisions on practices that should be implemented for reducing unnecessary caesarean births safely.

Protocol Registration: PROSPERO 2018 CRD42018090681. Available from: http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42018090681

Indications and determinants of caesarean section delivery: Evidence from a population-based study in Matlab, Bangladesh

BACKGROUND AND METHODS

Caesarean section (C-section) is a major obstetric intervention for saving lives of women and their newborns from pregnancy and childbirth related complications. Un-necessary C-sections may have adverse impact upon maternal and neonatal outcomes. In Bangladesh there is paucity of data on clinical indication of C-section at population level. We conducted a retrospective study in icddr,b Health and Demographic Surveillance System (HDSS) area of Matlab to look into the indications and determinants of C-sections. All resident women in HDSS service area who gave birth in 2013 with a known birth outcome, were included in the study. Women who underwent C-section were identified from birth and pregnancy files of HDSS and their indication for C-section were collected reviewing health facility records where the procedure took place, supplemented by face-to-face interview of mothers where data were missing. Indications of C-section were presented as frequency distribution and further divided into different groups following 3 distinct classification systems. Socio-demographic predictors were explored following statistical method of binary logistic regression.

FINDINGS

During 2013, facility delivery rate was 84% and population based C-section rate was 35% of all deliveries in icddr,b service area. Of all C-sections, only 1.4% was conducted for Absolute Maternal Indications (AMIs). Major indications of C-sections included: repeat C-section (24%), foetal distress (21%), prolonged labour (16%), oligohydramnios (14%) and post-maturity (13%). More than 80% C-sections were performed in for-profit private facilities. Probability of C-section delivery increased with improved socio-economic status, higher education, lower birth order, higher age, and with more number of Antenatal Care use and presence of bad obstetric history. Eight maternal deaths occurred, of which five were delivered by C-section.

CONCLUSIONS

C-section rate in this area was much higher than national average as well as global recommendations. Very few of C-sections were undertaken for AMIs. Routine monitoring of clinical indication of C-section in public and private facilities is needed to ensure rational use of the procedure.

Current Concepts in the Management of Meconium Aspiration Syndrome

In developing countries, meconium aspiration syndrome (MAS) is an important cause of morbidity and mortality among neonates. The concepts of pathophysiology and management of meconium stained amniotic fluid (MSAF) and meconium aspiration syndrome have undergone tremendous change in recent years. Routine intranatal and postnatal endotracheal suctioning of meconium in vigorous infants is no longer recommended. Recent studies have challenged its role even in non-vigorous infants. Supportive therapy like oxygen supplementation, mechanical ventilation and intravenous fluids are the cornerstone in the management of meconium aspiration syndrome. Availability of surfactant, inhaled nitric oxide, high frequency ventilators and extracorporeal membrane oxygenation has made it possible to salvage more infants with meconium aspiration syndrome. In this review the authors have discussed the current concepts in the pathophysiology and management of MAS. Drugs in trials and future therapeutic targets are also discussed briefly.

Amnioinfusion for chorioamnionitis

BACKGROUND

Chorioamnionitis is a leading cause of perinatal morbidity and mortality. Amnioinfusion aims at reducing the adverse effects of chorioamnionitis by dilution of the infective organisms or by an anti-microbial effect of the fluid infused.

OBJECTIVES

The objective of this review was to determine the effect of amnioinfusion on clinical and sub-clinical chorioamnionitis, fetal well-being, fetal heart rate characteristics and perinatal and maternal morbidity and mortality.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 July 2016), PubMed, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (6 July 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised clinical trials (RCTs) of amnioinfusion (treatment group) versus no amnioinfusion in women with chorioamnionitis.We would have also considered trials comparing amnioinfusion with sham amnioinfusion; different types or volumes of amnioinfusion fluid but none were identified.Cluster-RCTs and quasi-RCTs were eligible for inclusion but none were identified. We identified one study published in abstract form but it did not contain any numerical data and has therefore been excluded. Studies using a cross-over design are not an appropriate study design and thus were not eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed potential studies for inclusion and assessed trial quality. Both review authors independently extracted data and data were checked for accuracy.

MAIN RESULTS

We included one small trial (with data from 34 participants) comparing transcervical amnioinfusion with no amnioinfusion. The trial was considered to be at a high risk of bias overall, due to small numbers, inconsistency in the reporting and lack of information on blinding. Meta-analysis was not possible. Transcervical amnioinfusion was with room temperature saline at 10 mL per minute for 60 minutes, then 3 mL per minute until delivery versus no amnioinfusion. All women received intrauterine pressure catheter, acetaminophen and antibiotics (ampicillin or, if receiving Group B beta streptococcal prophylaxis, penicillin and gentamycin). We did not identify any trials that used transabdominal amnioinfusion.Compared to no amnioinfusion, transcervical amnioinfusion had no clear effect on the incidence of postpartum endometritis (risk ratio (RR) 1.50, 95% confidence interval (CI) 0.29 to 7.87; absolute risk 176/1000 (95% CI 34 to 96) versus 118/1000;low-quality evidence). Nor was there a clear effect in the incidence of neonatal infection (RR 3.00, 95% CI 0.13 to 68.84; absolute risk 0/1000 (95% CI 0 to 0) versus 0/1000; low-quality evidence). The outcome of perinatal death or severe morbidity (such as neonatal encephalopathy, intraventricular haemorrhage, admission to intensive/high care) was not reported in the included trial.In terms of this review's secondary outcomes, the rate of caesarean section was the same in both groups (RR 1.00, 95% CI 0.35 to 2.83; absolute risk 294/1000 (95% CI 103 to 832) versus 294/1000; low-quality evidence). There was no clear difference in the duration of maternal antibiotic treatment between the amnioinfusion and no amnioinfusion control group (mean difference (MD) 16 hours, 95% CI -1.75 to 33.75); nor in the duration of hospitalisation (MD 3.00 hours, 95% CI -15.49 to 21.49). The study did not report any information about how many babies had a low Apgar score at five minutes after birth.Women in the amnioinfusion group had a lower temperature at delivery compared to women in the control group (MD -0.38°C, 95% CI -0.74 to -0.02) but this outcome was not pre-specified in the protocol for this review.The majority of this review's secondary outcomes were not reported in the included study.

AUTHORS' CONCLUSIONS

There is insufficient evidence to fully evaluate the effectiveness of using transcervical amnioinfusion for chorioamnionitis and to assess the safety of this intervention or women's satisfaction. We did not identify any trials that used transabdominal amnioinfusion. The evidence in this review can neither support nor refute the use of transcervical amnioinfusion outside of clinical trials. We included one small study that reported on a limited number of outcomes of interest in this review. The numbers included in this review are too small for meaningful assessment of substantive outcomes, where reported. For those outcomes we assessed using GRADE (postpartum endometritis, neonatal infection, and caesarean section), we downgraded the quality of the evidence to low - with downgrading decisions based on small numbers and a lack of information on blinding. The included study did not report on this review's other primary outcome (perinatal death or severe morbidity).The reduction in pyrexia, though not a pre-specified outcome of this review, may be of relevance in terms of benefits to the fetus of reduced exposure to heat. We postulate that the temperature reduction found may be a direct cooling effect of amnioinfusion with room temperature fluid, rather than reduction of infection. Larger trials are needed to confirm and extend the findings of the trial reviewed here. These should be randomised controlled trials; participants, women with chorioamnionitis; interventions, amnioinfusion; comparisons, no amnioinfusion; outcomes, maternal and perinatal outcomes including neurodevelopmental measures.Further research is justified to determine possible benefits or risks of amnioinfusion for chorioamnionitis, and to investigate possible benefits of reducing temperature in fetuses considered at risk of neurological damage. Research should include randomised trials to examine transcervical or transabdominal amnioinfusion compared with no infusion for chorioamnionitis and examine outcomes listed in the methods of this review.

Surfactant therapy and antibiotics in neonates with meconium aspiration syndrome: a systematic review and meta-analysis

Meconium aspiration syndrome (MAS), a common cause of respiratory failure in neonates, is associated with high mortality and morbidity. The objectives of this review were to evaluate the effects of administration of (a) surfactant-either as lung lavage (SLL) or bolus surfactant (BS) and (b) antibiotics on mortality and severe morbidities in neonates with MAS. We searched the following databases: MEDLINE via PubMed, Cochrane CENTRAL, WHOLIS and CABI using sensitive search strategies. We included eight studies on use of surfactant and three studies on use of antibiotics. Neither SLL nor BS reduced the risk of mortality in neonates with MAS (relative risk (RR) 0.38, 95% confidence interval (CI) 0.09 to 1.57; and RR 0.80, 95% CI 0.39 to 1.66, respectively). Both SLL and BS reduced the duration of hospital stay (mean difference -2.0, 95% CI -3.66 to -0.34; and RR -4.68, 95% CI -7.11 to -2.24 days, respectively) and duration of mechanical ventilation (mean difference -1.31, 95% CI -1.91 to -0.72; and mean difference 5.4, 95% CI -9.76 to -1.03 days). Neonates who received BS needed extracorporeal membrane oxygenation (ECMO) less often than the controls (RR 0.64, 95% CI 0.46 to 0.91). Use of antibiotics for MAS did not result in significant reduction in the risk of mortality, sepsis or duration of hospital stay. Surfactant administration either as SLL or BS for MAS was found to reduce the duration of mechanical ventilation and hospital stay; BS also reduced the need for ECMO. Administration of antibiotics did not show any significant clinical benefits in neonates with MAS and no evidence of sepsis. Given the limited number of studies and small number of neonates enrolled, there is an urgent need to generate more evidence on the efficacy and cost-effectiveness of these two treatment modalities before recommending them in routine clinical practice.

Meconium aspiration syndrome: a role for fetal systemic inflammation

BACKGROUND

Meconium aspiration syndrome (MAS) is a leading cause of morbidity and mortality in term infants. Meconium-stained amniotic fluid (MSAF) occurs in approximately 1 of every 7 pregnancies, but only 5% of neonates exposed to MSAF develop MAS. Why some infants exposed to meconium develop MAS while others do not is a fundamental question. Patients with MSAF have a higher frequency of intraamniotic inflammation/infection than those with clear fluid. We propose that fetal systemic inflammation is a risk factor for the development of MAS in patients with MSAF.

OBJECTIVE

We sought to investigate whether intraamniotic inflammation and funisitis, the histopathologic landmark of a fetal inflammatory response, predispose to MAS.

STUDY DESIGN

A prospective cohort study was conducted from 1995 through 2009. Amniotic fluid (AF) samples (n = 1281) were collected at the time of cesarean delivery from women who delivered singleton newborns at term (gestational age ≥38 weeks). Intraamniotic inflammation was diagnosed if the AF concentration of matrix metalloproteinase-8 was >23 ng/mL. Funisitis was diagnosed by histologic examination if inflammation was present in the umbilical cord.

RESULTS

The prevalence of MSAF was 9.2% (118/1281), and 10.2% (12/118) of neonates exposed to MSAF developed MAS. There were no significant differences in the median gestational age or umbilical cord arterial pH at birth between neonates who developed MAS and those who did not (each P > .1). Mothers whose newborns developed MAS had a higher median of AF matrix metalloproteinase-8 (456.8 vs 157.2 ng/mL, P < .05). Newborns exposed to intraamniotic inflammation had a higher rate of MAS than those who were not exposed to intraamniotic inflammation [13.0% (10/77) vs 0% (0/32), P = .03], as did those exposed to funisitis [31.3% (5/16) vs 7.3% (6/82); relative risk, 4.3; 95% confidence interval, 1.5-12.3]. Among the 89 newborns for whom both AF and placental histology were available, MAS was more common in patients with both intraamniotic inflammation and funisitis than in those without intraamniotic inflammation and funisitis [28.6% (4/14) vs 0% (0/28), P = .009], while the rate of MAS did not show a significant difference between patients with intraamniotic inflammation alone (without funisitis) and those without intraamniotic inflammation and funisitis [10.9% (5/46) vs 0% (0/28)].

CONCLUSION

The combination of intraamniotic inflammation with fetal systemic inflammation is an important antecedent of MAS. This concept has implications for the understanding of the mechanisms of disease responsible for MAS and for the development of prognostic models and therapeutic interventions for this disorder.

Antibiotics for meconium-stained amniotic fluid in labour for preventing maternal and neonatal infections

BACKGROUND

Chorioamnionitis is more likely to occur when meconium-stained amniotic fluid (MSAF) is present. Meconium may enhance the growth of bacteria in amniotic fluid by serving as a growth factor, inhibiting bacteriostatic properties of amniotic fluid. Many adverse neonatal outcomes related to MSAF result from meconium aspiration syndrome (MAS). MSAF is associated with both maternal and newborn infections. Antibiotics may be an effective option to reduce such morbidity.

OBJECTIVES

The objective of this review is to assess the efficacy and side effects of prophylactic antibiotics for MSAF during labour in preventing maternal and neonatal infections.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2014). 

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing prophylactic antibiotics with placebo or no treatment during labour for women with MSAF.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

We included two studies with 362 pregnant women. Both studies compared ampicillin-sulbactam (N = 183) versus normal saline (N = 179) in pregnant women with MSAF. Prophylactic antibiotics appeared to have no statistically significant reduction in the incidence of neonatal sepsis (risk ratio (RR) 1.00, 95% CI 0.21 to 4.76), neonatal intensive care unit (NICU) admission (RR 0.83, 95% CI 0.39 to 1.78) and postpartum endometritis (RR 0.50, 95% CI 0.18 to 1.38). However, there was a significant decrease in the risk of chorioamnionitis (RR 0.36, 95% CI 0.21 to 0.62). No serious adverse effects were reported. Drug resistance, duration of mechanical ventilation and duration of admission to NICU/hospital were not reported. Most of the domains for risk of bias were at low risk of bias for one study and at unclear risk of bias for the other study. The quality of the evidence using GRADE was low for neonatal sepsis, postpartum endometritis, and neonatal mortality and morbidity prior to discharge (Neonatal intensive care admissions) and of moderate quality for chorioamnionitis.

AUTHORS' CONCLUSIONS

Current evidence indicates that compared to placebo, antibiotics for MSAF in labour may reduce chorioamnionitis. There was no evidence that antibiotics could reduce postpartum endometritis, neonatal sepsis and NICU admission. This systematic review identifies the need for more well-designed, adequately powered RCTs to assess the effect of prophylactic antibiotics in the incidence of maternal and neonatal complications.

Amnioinfusion for third trimester preterm premature rupture of membranes

BACKGROUND

Preterm premature rupture of membranes (PPROM) is a leading cause of perinatal morbidity and mortality. Amnioinfusion aims to restore amniotic fluid volume by infusing a solution into the uterine cavity.

OBJECTIVES

The objective of this review was to assess the effects of amnioinfusion for PPROM on perinatal and maternal morbidity and mortality.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 December 2013).

SELECTION CRITERIA

Randomised trials of amnioinfusion compared with no amnioinfusion in women with PPROM.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion. Two review authors independently assessed trial quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included five trials, of moderate quality, but we only analysed data from four studies (with a total of 241 participants). One trial did not contribute any data to the review.Transcervical amnioinfusion improved fetal umbilical artery pH at delivery (mean difference 0.11; 95% confidence interval (CI) 0.08 to 0.14; one trial, 61 participants) and reduced persistent variable decelerations during labour (risk ratio (RR) 0.52; 95% CI 0.30 to 0.91; one trial, 86 participants).Transabdominal amnioinfusion was associated with a reduction in neonatal death (RR 0.30; 95% CI 0.14 to 0.66; two trials, 94 participants), neonatal sepsis (RR 0.26; 95% CI 0.11 to 0.61; one trial, 60 participants), pulmonary hypoplasia (RR 0.22; 95% CI 0.06 to 0.88; one trial, 34 participants) and puerperal sepsis (RR 0.20; 95% CI 0.05 to 0.84; one trial, 60 participants). Women in the amnioinfusion group were also less likely to deliver within seven days of membrane rupture (RR 0.18; 95% CI 0.05 to 0.70; one trial, 34 participants). These results should be treated with circumspection as the positive findings were mainly due to one trial with unclear allocation concealment.

AUTHORS' CONCLUSIONS

These results are encouraging but are limited by the sparse data and unclear methodological robustness, therefore further evidence is required before amnioinfusion for PPROM can be recommended for routine clinical practice.