Use of maternal plasma level of zinc-coproporphyrin in the prediction of intrauterine passage of meconium: a pilot study

Activation of Toll-like receptors in meconium aspiration syndrome

OBJECTIVE

Meconium aspiration syndrome (MAS) is a common cause of neonatal morbidity and mortality. Incomplete understanding of the pathogenesis of MAS has hindered the development of specific therapies. We hypothesized that activation of Toll-like receptors (TLRs) might play a role in the pathogenesis of MAS. The present study evaluated the expression of TLR 1, 4, 7, 8 and 9 in neonates with MAS.

STUDY DESIGN

The study included 39 neonates with MAS and 17 healthy gestational age-matched neonates as controls. Neonates with maternal chorioamnionitis, perinatal asphyxia, sepsis and congenital malformations were excluded. Good-quality total RNA from umbilical cord blood was reverse transcribed to prepare cDNA using Bio-Rad reverse transcription kit. This cDNA was used to study the expression status of TLR 1, 4, 7, 8 and 9 by real-time quantitative polymerase chain reaction.

RESULTS

Compared with controls, TLR1 and TLR4 were highly expressed, TLR9 was moderately expressed, TLR7 was weakly expressed and TLR8 expression was neutral in neonates with MAS. Within the MAS group, no difference in TLR expression was observed with respect to consistency of meconium, severity of the disease, oxygenation index and outcome.

CONCLUSION

There is activation of TLRs in neonates with MAS. We speculate that these TLRs probably act as endogenous ligands for various components of meconium that initiate the inflammatory cascade of MAS and contribute to its pathogenesis.

Meconium Amniotic Fluid is Associated with Endomyometritis

PURPOSE

This study aimed to determine whether MSAF is associated with endometritis after delivery.

METHODS

This cohort study was conducted from 2012 to 2013 in Kosar Hospital of Qazvin, Iran. All women with cesarean delivery (1239 women) beyond 37 weeks of gestational age participated in the study. Data were collected on rates of endomyometritis, quality of amniotic fluid and were analyzed with bivariate and multivariate statistics. Probability values of <.05 were considered statistically significant.

RESULTS

We found that among 1239 women with cesarean delivery at term 2.34 % were diagnosed with endometritis. Compared with deliveries with clear amniotic fluid, those with MSAF had higher rates of endomyometritis (1.5 vs 3.2 %, P < .04).

CONCLUSION

We found that the presence of MSAF is associated with puerperal infection even when being controlled for confounders.

Amniotic fluid embolism pathophysiology suggests the new diagnostic armamentarium: β-tryptase and complement fractions C3-C4 are the indispensable working tools

Amniotic fluid embolism (AFE) is an uncommon obstetric condition involving pregnant women during labor or in the initial stages after delivery. Its incidence is estimated to be around 5.5 cases per 100,000 deliveries. Therefore, this paper investigated the pathophysiological mechanism, which underlies AFE, in order to evaluate the role of immune response in the development of this still enigmatic clinical entity. The following databases (from 1956 to September 2014) Medline, Cochrane Central, Scopus, Web of Science and Science Direct were used, searching the following key words: AFE, pathophysiology, immune/inflammatory response, complement and anaphylaxis. The main key word “AFE” was searched singularly and associated individually to each of the other keywords. Of the 146 sources found, only 19 were considered appropriate for the purpose of this paper. The clinical course is characterized by a rapid onset of symptoms, which include: acute hypotension and/or cardiac arrest, acute hypoxia (with dyspnoea, cyanosis and/or respiratory arrest), coagulopathies (disseminated intravascular coagulation and/or severe hemorrhage), coma and seizures. The pathology still determines a significant morbidity and mortality and potential permanent neurological sequelae for surviving patients. At this moment, numerous aspects involving the pathophysiology and clinical development are still not understood and several hypotheses have been formulated, in particular the possible role of anaphylaxis and complement. Moreover, the detection of serum tryptase and complement components and the evaluation of fetal antigens can explain several aspects of immune response.

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.

Bacteria and endotoxin in meconium-stained amniotic fluid at term: could intra-amniotic infection cause meconium passage?

BACKGROUND

Meconium-stained amniotic fluid (MSAF) is a common occurrence among women in spontaneous labor at term, and has been associated with adverse outcomes in both mother and neonate. MSAF is a risk factor for microbial invasion of the amniotic cavity (MIAC) and preterm birth among women with preterm labor and intact membranes. We now report the frequency of MIAC and the presence of bacterial endotoxin in the amniotic fluid of patients with MSAF at term.

MATERIALS AND METHODS

We conducted a cross-sectional study including women in presumed preterm labor because of uncertain dates who underwent amniocentesis, and were later determined to be at term (n = 108). Patients were allocated into two groups: (1) MSAF (n = 66) and (2) clear amniotic fluid (n = 42). The presence of bacteria was determined by microbiologic techniques, and endotoxin was detected using the Limulus amebocyte lysate (LAL) gel clot assay. Statistical analyses were performed to test for normality and bivariate comparisons.

RESULTS

Bacteria were more frequently present in patients with MSAF compared to those with clear amniotic fluid [19.6% (13/66) versus 4.7% (2/42); p < 0.05]. The microorganisms were Gram-negative rods (n = 7), Ureaplasma urealyticum (n = 4), Gram-positive rods (n = 2) and Mycoplasma hominis (n = 1). The LAL gel clot assay was positive in 46.9% (31/66) of patients with MSAF, and in 4.7% (2/42) of those with clear amniotic fluid (p < 0.001). After heat treatment, the frequency of a positive LAL gel clot assay remained higher in the MSAF group [18.1% (12/66) versus 2.3% (1/42), p < 0.05]. Median amniotic fluid IL-6 concentration (ng/mL) was higher [1.3 (0.7-1.9) versus 0.6 (0.3-1.2), p = 0.04], and median amniotic fluid glucose concentration (mg/dL) was lower [6 (0-8.9) versus 9 (7.4-12.6), p < 0.001] in the MSAF group, than in those with clear amniotic fluid.

CONCLUSION

MSAF at term was associated with an increased incidence of MIAC. The index of suspicion for an infection-related process in postpartum women and their neonates should be increased in the presence of MSAF.

Amniotic fluid ferritin as a marker of intestinal damage in gastroschisis: a time course experimental study

BACKGROUND/PURPOSE

Intestinal damage (ID) is closely related to morbidity and mortality in gastroschisis. This study was performed to determine the intraamniotic substances that may correlate ID and also to verify their time course levels that would be useful for determining when ID starts in gastroschisis.

METHODS

In this study, 13-day-old fertilized chick eggs were used. The amnioallantoic membrane was perforated to create amnioallantoic cavity in all embryos. Gastroschisis was created in gastroschisis group to simulate human gastroschisis. Amnioallantoic fluid samples were collected from the embryos on the 13th to 19th gestational days, and the intestines of each group were harvested for evaluation. Amnioallantoic levels of interleukin-8, ferritin, alkaline phosphatase, and amylase were measured. Serosal thickness of the intestines in each group was evaluated.

RESULTS

Increasing amnioallantoic fluid levels of interleukin-8, alkaline phosphatase, and amylase were found in both groups. In contrast to control group, ferritin levels, as a sign of inflammation, were found increased only in gastroschisis group. Histopathologic examination of intestines in the gastroschisis group showed a significant increase in the serosal thickness especially after the 16th day.

CONCLUSION

Increases in amnioallantoic fluid levels of ferritin show promise as a marker for determining ID encountered in gastroschisis but warrant further investigation.

Induction of fetal diuresis with intraamniotic furosemide increases the clearance of intraamniotic substances: An alternative therapy aimed at reducing intraamniotic meconium concentration

BACKGROUND/PURPOSE

Contact with amniotic fluid (AF) causes intestinal damage in gastroschisis. Intraamniotic meconium has been shown to be responsible for intestinal damage, and occurrence of this damage has been shown to depend on the concentration of intraamniotic meconium. When intraamniotic meconium concentration is lowered below threshold level by exchanging AF with saline in gastroschisis, intestinal damage can be prevented. Theoretically, induction of fetal diuresis with intraamniotic furosemide may increase AF volume and fetal swallowing rate, thus, increase absorption of AF by intestines; therefore, the clearance of meconium from the AF may increase. An experimental study was planned to investigate the effects of intraamniotic diuretic injection on the clearance of intraamniotic substances.

METHODS

Pregnant rabbits on the 23rd to 25th gestational day were divided into 2 groups as furosemide and control. Technetium tc99m labeled "tin colloid" was injected into the amniotic cavity, and AF sample was taken 10 minutes later. Furosemide was injected into the amniotic cavity afterwards. Two and 6 hours later, AF samples were obtained. Intestines were harvested at the end of the study. Control group received intraamniotic saline instead of furosemide. Radioactivities of the AF samples and intestines were determined by gamma counter. Clearance of the radioisotope from AF and intestinal accumulation were calculated.

RESULTS

The clearance of the radioisotope from AF was increased significantly in the furosemide group (n = 10) compared with the control group (n = 8; P <.01). Gastrointestinal accumulation of the radioisotope in the furosemide group was 4-fold higher than that the control group (P <.01).

CONCLUSIONS

Induction of fetal diuresis with intraamniotic furosemide accelerates the clearance of intraamniotic substances. This is probably caused by increased urinary output rate, which increases AF volume and consequently results in increased fetal swallowing of AF. In the diseases like gastroschisis and myelomeningocele, in which the contact with AF causes tissue damage, the elimination of meconium from AF in a somewhat natural manner like this method, should be studied further because it may be an alternative minimal invasive in utero treatment modality.

Intestinal damage in gastroschisis correlates with the concentration of intraamniotic meconium

BACKGROUND/PURPOSE

Contact with amniotic fluid (AF) causes intestinal damage in gastroschisis, which has been shown to be caused by intraamniotic meconium. However, whether this intraamniotic meconium-induced intestinal damage is concentration dependent has not been investigated previously. The purpose of this study is to investigate the effects of intraamniotic human meconium at various concentrations on the intestines of chick embryo with gastroschisis.

METHODS

Five-day-old fertilized chick eggs were used. Gastroschisis was created through the amniotic cavity without opening the allantoic cavity. Sterile meconium was obtained from newborn humans. Meconium suspensions at various concentrations were prepared using saline and instilled into the amniotic cavity.

RESULTS

Intraamniotic 1:200 and 1:400 meconium was found to cause intestinal damage. Meconium concentrations lower than 1:400 did not cause intestinal damage. Histopathologic examination of the intestines of the 1:200 and 1:400 meconium groups showed serosal thickening, inflammation, focal fibrin, and collagen deposits. Histopathologic features of the intestines of the 1:600 and 1:800 meconium groups did not differ from the intestines of the control group.

CONCLUSION

Intraamniotic meconium, which is responsible for intestinal damage in gastroschisis, must reach a threshold level to induce intestinal damage. J Pediatr Surg 36:1811-1815.