Physiology of amniotic fluid volume regulation

A dynamic flow fetal membrane organ-on-a-chip system for modeling the effects of amniotic fluid motion

Fetal membrane (amniochorion), the innermost lining of the intrauterine cavity, surround the fetus and enclose amniotic fluid. Unlike unidirectional blood flow, amniotic fluid subtly rocks back and forth, and thus, the innermost amnion epithelial cells are continuously exposed to low levels of shear stress from fluid undulation. Here, we tested the impact of fluid motion on amnion epithelial cells (AECs) as a bearer of force impact and their potential vulnerability to cytopathologic changes that can destabilize fetal membrane functions. A previously developed amnion membrane (AM) organ-on-chip (OOC) was utilized but with dynamic flow to culture human fetal amnion membrane cells. The applied flow was modulated to perfuse culture media back and forth for 48 h to mimic fluid motion. A static culture condition was used as a negative control, and oxidative stress (OS) condition was used as a positive control representing pathophysiological changes. The impacts of fluidic motion were evaluated by measuring cell viability, cellular transition, and inflammation. Additionally, scanning electron microscopy (SEM) imaging was performed to observe microvilli formation. The results show that regardless of the applied flow rate, AECs and AMCs maintained their viability, morphology, innate meta-state, and low production of pro-inflammatory cytokines. E-cadherin expression and microvilli formation in the AECs were upregulated in a flow rate-dependent fashion; however, this did not impact cellular morphology or cellular transition or inflammation. OS treatment induced a mesenchymal morphology, significantly higher vimentin to cytokeratin 18 (CK-18) ratio, and pro-inflammatory cytokine production in AECs, whereas AMCs did not respond in any significant manner. Fluid motion and shear stress, if any, did not impact AEC cell function and did not cause inflammation. Thus, when using an amnion membrane OOC model, the inclusion of a dynamic flow environment is not necessary to mimic in utero physiologic cellular conditions of an amnion membrane.

Evaluation of Fetal Cardiac Output and Modified Myocardial Performance Index in Pregnant Women with Idiopathic Polyhydramnios: A Case Control Study from a Tertiary Hospital

PURPOSE

This study aimed to investigate fetal cardiac output and myocardial performance index in pregnant women with idiopathic polyhydramnios and compare them to healthy pregnant women.

METHODS

Thirty patients admitted to Ankara City Hospital at 24-39 weeks of gestation with idiopathic polyhydramnios were included as the study group. Clinical characteristics, fetal cardiac output, and fetal modified myocardial performance index (Mod-MPI) were compared between the groups.

RESULTS

The combined cardiac output (CCO), left cardiac output (LCO), right cardiac output (RCO), pulmonary artery velocity time integral (PA-VTI), and aortic VTI were statistically significantly higher in the study group (p=0.003, p=0.028, p=0.002, p=0.000, and p=0.017, respectively).The idiopathic polyhydramnios group had a significantly higher Mod-MPI and isovolumetric contraction time (ICT) and a significantly lower ejection time (ET) compared to the controls (p=000, p=0.003, and p=0.023, respectively). In the idiopathic polyhydramnios group, the aortic max (p=0.009) and aortic VTI (p=0.047) values were significantly lower and the left ventricular outflow tract isovolumetric relaxation time (LVOT-IRT) (p=0.021) was significantly higher in cases where the NICU was required. According to the ROC analysis performed in the idiopathic polyhydramnios group, the optimal cut-off values of aortic max, aortic VTI, and LVOT-IRT in the prediction of the NICU requirement were (57.5, 0.089 and 41.5, respective cut-off value) (p=0.010, p=0.048, p=0.021, respectively).

CONCLUSIONS

Both fetal cardiac output and Mod-MPI values were altered in fetuses with idiopathic polyhydramnios.

Amniotic Fluid Disorders: From Prenatal Management to Neonatal Outcomes

Amniotic fluid volume assessment has become standard in the surveillance of fetal well-being, especially in high-risk pregnancies. Amniotic fluid disorders are a frequent and important topic in fetal and perinatal medicine. However, although important advances have been achieved, many important and challenging questions remain unanswered to date. An abnormally low amniotic fluid volume, referred to as oligohydramnios, has been traditionally considered a possible indicator of placental insufficiency or fetal compromise and is associated with an increased rate of obstetric interventions. An excess of amniotic fluid, referred to as polyhydramnios, may be secondary to fetal or maternal conditions and has been associated with a variety of adverse pregnancy outcomes, especially when it is severe. The ultrasonographic detection of an amniotic fluid disorder should prompt a proper workup to identify the underlying etiology. Data on the association of isolated oligohydramnios or idiopathic polyhydramnios with adverse obstetric and perinatal outcomes are conflicting. While the management of secondary oligohydramnios is usually guided by the underlying condition, the management of isolated oligohydramnios is poorly defined. Similarly, the management of idiopathic and secondary polyhydramnios is not yet standardized. There is an urgent need for randomized clinical trials to provide stronger recommendations on the management of these two common conditions.

Magnitude and associated factors of adverse perinatal outcomes among women with oligohydramnios at 3rd trimester at University of Gondar comprehensive specialized hospital, North West Ethiopia

Background

Oligohydramnios is a pregnancy condition characterized by low volume of amniotic fluid. Based on ultrasound measurement, it is defined as a single maximum vertical pocket of liquor less than 2 cm or summation of four quadrants vertical pockets of liquor measurement less than 5 cm. It is associated with multiple adverse perinatal outcomes (APO) and complicates 0.5%-5% of pregnancies.

Objective

To assess magnitude and associated factors of adverse perinatal outcome among women with oligohydramnios at 3rd trimester at University of Gondar Comprehensive Specialized Hospital, North West Ethiopia.

Methods

Institution based cross-sectional study was employed from April 1 to September 30, 2021 in which 264 participants were involved. All women with oligohydramnios at 3rd trimester who meet the inclusion criteria were included. Semi- structured questionnaire was used for data collection after Pre-tested. Collected data was checked for completeness; clarity then coded and entered using Epi data version 4.6.0.2 then exported to STATA version 14.1 for analysis.

Result

The magnitude of APO was 46.6% (95%CI: 40.5-52.7%). Null parity [AOR =  2.2, 95%CI (1.2-4.2)], presence of hypertensive disorders of pregnancy (HDP) [AOR = 4.9, 95%CI (2.0-12.1)] and presence of intrauterine growth restriction (IUGR) [AOR = 8.4, 95%CI (3.5-20.2)] were found to be predictors of APO.

Conclusion

Third trimester oligohydramnios is associated with APO. The presence of HDP, IUGR and being nulliparous were predictors of APO.

Aquaporins in Fetal Development

Water homeostasis is essential for fetal growth, and it depends on the successful development of the placenta. Many aquaporins (AQPs) were identified from blastocyst stages to term placenta. In the last years, cytokines, hormones, second messengers, intracellular pH, and membrane proteins were found to regulate their expression and function in the human placenta and fetal membranes. Accumulated data suggest that these proteins may be involved not only in the maintenance of the amniotic fluid volume homeostasis but also in the development of the placenta and fetal organs. In this sense, dysregulation of placental AQPs is associated with gestational disorders. Thus, current evidence shows that AQPs may collaborate in cellular events including trophoblast migration and apoptosis. In addition, aquaglyceroporins are involved in energy metabolism as well as urea elimination across the placenta. In the last year, the presence of AQP9 in trophoblast mitochondria opened new hypotheses about its role in pregnancy. However, much further work is needed to understand the importance of these proteins in human pregnancies.

The incidence and determinants of the meconium-aspiration syndrome among mothers with meconium-stained amniotic fluid after emergency cesarean section: A prospective cross-sectional study in a specialized hospital, south Ethiopia

Background

Meconium aspiration syndrome is respiratory distress diagnosed in neonates delivered with meconium-stained amniotic fluid that is unexplained by other pathologies. It has severe neonatal respiratory complications and a significant impact on the prevalence of neonatal mortality.

Objective

To identify the incidence and determinants associated with meconium aspiration syndrome among mothers with meconium-stained amniotic fluid after emergency cesarean section in Wolkite University specialized hospitals in Ethiopia from September 1, 2021, to August 30, 2022.

Method

An institution-based cross-sectional study was done prospectively through meticulous chart review and interviews with 275 mothers with meconium-stained amniotic fluid who gave birth with an emergency cesarean section. Data were entered using EpiData 7 and analyzed with SPSS 26. The association between independent variables and the meconium-aspiration syndrome was estimated using an odds ratio with 95% confidence intervals. The statistical significance of the association was declared at a p-value of 0.05.

Result

The prevalence of the meconium-aspiration syndrome is 28.7%. The factors associated are: latent phase (AOR: 2.580; 95% CI: 1.126, 5.913), low 1st minute APGAR score (AOR: 2.43; 95% CI: 0.892, 6.625), and thick meconium (AOR: 31.018; 95% CI: 9.982, 96.390). The neonatal death rate associated with meconium aspiration syndrome is 1.8%, and thick meconium contributed to 65% of admissions to the neonatal intensive care unit and all deaths.

Conclusion

The incidence of meconium aspiration syndrome is high, and thick meconium, meconium at early labor, and low APGAR scores all contributed to this. Thick meconium has a substantial effect on neonatal mortality and morbidity. Therefore, an improvement in the quality of obstetric and neonatal care through early intervention in the case of thick meconium and meconium in the early phase of labor is recommended.

Predictive factors for survival in patients with oligohydramnios secondary to antenatal kidney disease

BACKGROUND

Renal oligohydramnios (ROH) is caused by bilateral congenital abnormalities, either of renal parenchymal or obstructive origin. ROH is a poor prognostic factor of neonatal survival; lung hypoplasia is reported to be the main cause of mortality. We aimed to describe the fetal morbidity and pre- and postnatal mortality in case of ROH due to renal congenital pathologies and to find predictive risk factors for morbidity and mortality.

METHODS

All data were collected in Trousseau Hospital in the obstetric, neonatology, and pediatric nephrology units, from 2008 to 2020.

RESULTS

We included 66 fetuses with renal parenchymal pathologies posterior urethral valves (PUV) (N = 25), bilateral kidney agenesis (N = 10), hypodysplasia (N = 16), and polycystic kidney disease (N = 10) causing oligohydramnios identified on antenatal ultrasound. Total pre- and postnatal mortality was 76% (50/66). Mortality, excepting termination of pregnancy (TOP), was 65%. The presence of pneumomediastinum and pneumothorax was not different in survivors and non-survivors. Fetuses with kidneys having features of hypodysplasia on ultrasound at T2 and those with oligohydramnios before 32 weeks GA had a higher risk of death. There was a significant difference in plasma creatinine of the surviving patients compared to the deceased patients, from day 3 onwards (183 µmol/L [88; 255] vs. 295 µmol/L [247; 326]; p = 0.038).

CONCLUSIONS

The main differences between survivors and non-survivors among patients with "renal oligohydramnios" were oligohydramnios detection before 32 weeks GA, dysplasia detection on the second trimester ultrasound, and increase of serum creatinine from day 3 onwards. A higher resolution version of the Graphical abstract is available as Supplementary information.

Association and Correlation Between Amniotic Fluid Index and Glucose Concentration

Purpose: To study the association and correlation between the amniotic fluid index, random glucose concentration, and serum glucose concentration after avoiding oral intake of sugar in a pregnant female with polyhydramnios.

Methods: The research was performed on pregnant women with polyhydramnios (n=104 ) after 28 weeks. USG was performed using a SAMSUNG HS 70A (Samsung Electronics Pvt. Ltd., Seoul, South Korea) and a GE Voluson P8 (GE Healthcare, Little Chalfont, UK). We measured amniotic fluid index and took a blood sample for hemoglobin (Hb)A1C, fasting blood glucose, post-prandial and random blood glucose, and also performed a glucose tolerance test in pregnant women.

Results: This is a prospective study, all 104 patients that were recruited in this study were pregnant females with polyhydramnios mainly from the urban and rural zone with different age groups (between 21 and 37 years). In our study, we observed that after avoiding oral intake of sugar in pregnant females with polyhydramnios, it was concluded that the amnionic fluid index lies towards the lower side. Polyhydramnios is more common in the urban zone and among older pregnant females. Out of 104 pregnant females with polyhydramnios, 82 were diagnosed with gestational diabetes after 28 weeks.

Conclusion: In this study, we have concluded that the earliest and most sensitive predictor for gestational diabetes is a rise in the amniotic fluid index which could have been prevented by avoiding oral intake of sugar. Early prediction of gestational diabetes can be made by amniotic fluid index even before glucose concentration. We observed that by reducing oral intake of sugar, the amniotic fluid index drops down in pregnant females

Oesophageal atresia: sonographic signs may prenatally predict surgical complexity

OBJECTIVE

Oesophageal atresia (OA) is a major anomaly of varying severity. The complexity of surgical correction highly depends on the gap length of missing oesophagus and the presence of a distal fistula. The aim of this study was to identify antenatal sonographic findings associated with presence of a distal fistula and type of surgical repair METHODS: Prenatal medical records of neonates postnatally diagnosed with OA were reviewed. Sonographic signs of OA (small/absent stomach, polyhydramnios, oesophageal pouch) and the trimester at sign detection were recorded and compared between (1) OA with and without a distal fistula and (2) early one-step versus delayed two-step anastomosis. Multivariate analysis was performed.

RESULTS

Overall, 80 cases of OA were included. Absence of a distal fistula was significantly associated with higher rates of small/absent stomach (100% vs 28.6%, P<0.0001), oesophageal pouch (100% vs 24.3%, P<0.0001) and severe polyhydramnios (66.7% vs 22.9%, P=0.006), compared with OA with a distal fistula.Cases requiring a delayed two-step repair had higher rates of small/absent stomach (84.2% vs 16.7%, P>0.0001), severe polyhydramnios (47.4% vs 16.7%, P=0.008) and oesophageal pouch (73.7% vs 18.5%, P<0.0001), compared with those corrected in an early one-step anastomosis.Multivariate logistic regression found small/absent stomach and pouch to be significantly and independently associated with a delayed two-step anastomosis.

CONCLUSION

OA without a distal fistula is associated with higher rates of prenatal sonographic signs. Both small/absent stomach and a pouch are independently associated with a delayed two-step anastomosis. These findings may help improve antenatal parental counselling regarding the anticipated surgical repair.

Contribution of aquaporins in the transamniotic water flux

We explored the contribution of each aquaporin (AQP) expressed in human amnion in the transcellular water flux across the human amnion. Human amnion was placed between two lucite chambers and net water transport (Jw) was recorded by applying a hydrostatic (7 cm H₂O) and an osmotic (40 mOsm PEG 8000) pressure gradients. The hydrostatic (Phydr) and osmotic (POsm) permeabilities were calculated before and after the blocking of AQPs. Phdr showed no significant difference after the blocking of AQPs, while POsm was dramatically reduced. Interestingly, we also found that the blocking of AQP1 produced the highest decrease of POsm (80 ± 1%). Our results strongly suggested that AQP1 seems to contribute more to the maintenance of AF volume homeostasis.

Correlation of amniotic fluid index and placental aquaporin 1 levels in terms of preeclampsia

INTRODUCTION

Aquaporin 1 (AQP1) plays an important role in regulation of maternal-fetal fluid exchange and amniotic fluid volume. This present study aimed to determine the relationship between amniotic fluid index and placental AQP1 levels in terms of preeclampsia, and to reveal possible pathophysiological changes of AQP1 expression under preeclamptic conditions.

METHODS

Placental tissues and medical records information were obtained from 389 preeclamptic and 447 uncomplicated pregnancies. Placental AQP1 levels were analyzed by molecular biological methods, DNA methylation within gene promotor was determined by targeted bisulfite sequencing assay.

RESULTS

Here, we found that preeclamptic pregnancy had a greater frequency of oligohydramnios, and higher placental AQP1 levels. There was a significantly inverse correlation between amniotic fluid index and placental AQP1 levels in preeclampsia cases. Additionally, the increased AQP1 was correlated with a decreased DNA methylation within its gene promoter.

DISCUSSION

Overall, this was the first description that a greater frequency of oligohydramnios in preeclampsia was strongly associated with reprogrammed AQP1 expression via a DNA methylation-mediated epigenetic mechanism. This study suggested AQP1 might play an important role in regulating maternal-fetal fluid balance under preeclamptic conditions, providing new information for further understanding the pathophysiological mechanism of oligohydramnios in preeclampsia.

Dynamic thiol/disulphide homeostasis and ischemic modified albumin levels in isolated oligohydramnios

OBJECTIVE

Oligohydramnios is defined as amniotic fluid index in ultrasonographic measurement is less than 5 percentile according to gestational age, the amniotic fluid volume is ≤ 5 cm, or if the single deepest dial is < 2 cm. The condition of oligohydramnios that not with fetal structural/chromosomal abnormalities, intrauterine growth retardation, intrauterine infection and maternal disease is described as isolated oligohydramnios (IO). The aim of this study is to examine whether oxidative stress and reactive oxygen species (ROS) have a place in the pathophysiology of IO.

MATERIALS AND METHODS

In this prospective case-control study, a total of 126 participants were included. The patient group consisted of 65 patients who were diagnosed IO, and the control group consisted of 61 healthy normal pregnants. Native thiol (-SH), total thiol (-SH + -SS), dynamic disulfide (-SS), IMA values from maternal serum were measured and compared between groups.

RESULTS

Maternal serum -SH and -SH + -SS values were significantly lower in the IO group than in the control group (409.47 ± 55.36 μmol/L vs. 437.40 ± 48.68 μmol/L, p = 0.03 and 457.40 ± 63.01 μmol/L vs. 484.59 ± 52.75 μmol/L, p = 0.01). In the IO group when -SS/-SH and -SS/-SH + -SS ratio was found to be statistically significantly higher than control group (5.84 ± 1.1 vs 5.41 ± 0.71, p = 0.01 and 5.2 ± 0.88 vs 4.8 ± 0.58, p = 0.01), -SH/-SH + -SS ratio was significantly lower (89.56 ± 1.7 vs 90.24 ± 1.16, p = 0.01). There was no significant difference in terms of -SS value (p = 0.66). IMA value was significantly higher in the IO group than control group (0.76 ± 0.10 ABSU vs 0.68 ± 0.06, p < 0.01). It is seen as a result of ROC analysis that -SH, -SH + -SS, -SS/-SH, -SS/-SH + -SS, -SH/-SH + -SS and IMA values have a diagnostic value for IO (p < 0.05).

CONCLUSION

The thiol/disulfide balance shifted towards oxidative stress in IO compared to control group. So oxidative stress and ROS have a place in the pathophysiology of IO.

Ramadan Fasting during Pregnancy and Health Outcomes in Offspring: A Systematic Review

Ramadan is one of the five pillars of Islam, during which fasting is obligatory for all healthy individuals. Although pregnant women are exempt from this Islamic law, the majority nevertheless choose to fast. This review aims to identify the effects of Ramadan fasting on the offspring of Muslim mothers, particularly on fetal growth, birth indices, cognitive effects and long-term effects. A systematic literature search was conducted until March 2020 in Web of Science, Pubmed, Cochrane Library, Embase and Google Scholar. Studies were evaluated based on a pre-defined quality score ranging from 0 (low quality) to 10 (high quality), and 43 articles were included. The study quality ranged from 2 to 9 with a mean quality score of 5.4. Only 3 studies had a high quality score (>7), of which one found a lower birth weight among fasting women. Few medium quality studies found a significant negative effect on fetal growth or birth indices. The quality of articles that investigated cognitive and long-term effects was poor. The association between Ramadan fasting and health outcomes of offspring is not supported by strong evidence. To further elucidate the effects of Ramadan fasting, larger prospective and retrospective studies with novel designs are needed.

Neonatal Immune System Ontogeny: The Role of Maternal Microbiota and Associated Factors. How Might the Non-Human Primate Model Enlighten the Path?

Interactions between the immune system and the microbiome play a crucial role on the human health. These interactions start in the prenatal period and are critical for the maturation of the immune system in newborns and infants. Several factors influence the composition of the infant's microbiota and subsequently the development of the immune system. They include maternal infection, antibiotic treatment, environmental exposure, mode of delivery, breastfeeding, and food introduction. In this review, we focus on the ontogeny of the immune system and its association to microbial colonization from conception to food diversification. In this context, we give an overview of the mother-fetus interactions during pregnancy, the impact of the time of birth and the mode of delivery, the neonate gastrointestinal colonization and the role of breastfeeding, weaning, and food diversification. We further review the impact of the vaccination on the infant's microbiota and the reciprocal case. Finally, we discuss several potential therapeutic interventions that might help to improve the newborn and infant's health and their responses to vaccination. Throughout the review, we underline the main scientific questions that are left to be answered and how the non-human primate model could help enlighten the path.

Evaluation of Fetal Exposures to Metals and Metalloids through Meconium Analyses: A Review

This paper surveys the existing scientific literature on metals concentrations in meconium. We examine some 32 papers that analyzed meconium for aluminum, arsenic, barium, calcium, chromium, copper, iron, lithium, magnesium, manganese, zinc, lead, mercury, manganese, molybdenum, nickel, phosphorus, lead, antimony, selenium, tin, vanadium, and zinc. Because of the lack of detail in the statistics it is not possible to do a rigorous meta-analysis. What stands out is that almost every study had subjects with seemingly large amounts of at least one of the metals. The significance of metals in meconium is not clear beyond an indication of exposure although some studies have correlated metals in meconium to a number of adverse outcomes. A number of outstanding questions have been identified that, if resolved, would greatly increase the utility of meconium analysis for assessment of long-term gestational metals exposures. Among these are questions of the developmental and long-term significance of metals detected in meconium, the kinetics and interactions among metals in maternal and fetal compartments and questions on best methods for meconium analyses.

Evaluation of short-term safety of ultrasound-guided foetal fluid sampling in the dog (Canis lupus familiaris)

BACKGROUND

In humans, analysis of amniotic fluid is widely used for diagnostic and prognostic purposes. Amniocentesis has scarcely been used in veterinary medicine to date, despite a tremendous potential for clinical and research applications in dogs. Our study aimed to establish a safe method for foetal fluid sampling in female dogs.

METHODS

Two transabdominal ultrasound-guided methods were assessed: the "free hand" and the needle-guided bracket sampling. In addition, through a subsequent routinely scheduled ovariohysterectomy, fluid was directly collected. Samples from 98 conceptuses were collected at day 46.7 ± 7.5 of pregnancy.

RESULTS

The amount of fluid retrieved varied between 0.5 and 5.0 ml per collection. Macroscopic examination of the uterus and conceptuses identified 53% of the puncture sites. Neither fluid leakage nor foetal injury was detected, and six hematomas (5.8%) were visible. Ultrasound-guided foetal fluid collection was found to be potentially safe, and it can be performed by using either transabdominal method.

CONCLUSION

Foetal fluid collection is possible with relative ease and low short-term risk, and may open paths for diagnostic, therapeutic and research purposes in dogs. The procedure can provide new insights into prenatal clinical medicine, including diagnostics of foetal deaths, early identification of heritable diseases and so on.

Prenatal androgen exposure and children's gender-typed behavior and toy and playmate preferences

We report findings from two studies investigating possible relations of prenatal androgen exposure to a broad measure of children's gender-typed behavior, as well as specifically to children's toy and playmate preferences. Study 1 investigated these outcomes for 43 girls and 38 boys, aged 4 to 11 years, with congenital adrenal hyperplasia (CAH, a genetic condition causing increased adrenal androgen production beginning prenatally) compared to similarly-aged, unaffected relatives (41 girls, 31 boys). The predicted sex differences were found for all of the outcome measures. Furthermore, girls with CAH showed increased male-typical and decreased female-typical behavior and toy and playmate preferences compared to unaffected girls. Study 2 investigated the relationship of amniotic fluid testosterone to gender-typed behavior and toy and playmate preferences in typically developing children (48 girls, 44 boys) aged 3 to 5 years. Although the predicted sex differences were found for all of the outcome measures, amniotic fluid testosterone was not a significant correlate, in the predicted direction, of any outcome measure for either sex. The results of study 1 provide additional support for an influence of prenatal androgen exposure on children's gender-typed behavior, including toy and playmate preferences. The results of study 2 do not, but amniotic fluid testosterone may be an insufficiently sensitive measure of early androgen exposure. A more sensitive and reliable measure of prenatal androgen exposure may be needed to consistently detect relations to later gender typed behavior in non-clinical populations.

Is chlorine and sodium levels in the amniotic fluid a new marker for fetal lung maturation and RDS severity?

BACKGROUND

Amniotic fluid (AF) is a dynamic liquid whose contents vary according to the needs of the fetus. Levels of the amniotic components have been used in numerous studies as potential biomarkers to screen pregnancy-related abnormalities. As a reflection of Na⁺ and Cl^- levels of fetal lung fluid, amniotic fluid's Na⁺ and Cl^- levels can be used as an indicator of lung maturation in the newborn period. This study aimed to investigate whether Na⁺ and Cl^- levels in the amniotic fluid would be a new marker to determine the severity of respiratory distress and pulmonary maturation in the newborn.

METHODS

This prospective cohort study was conducted at Hacettepe University Neonatal Intensive Care Unit. One hundred twenty single infants who were delivered with the cesarean section between January 2015 and March 2016 were included. Na⁺ and Cl^- levels were measured from AF.

RESULTS

There were 46 of 120 infants (33.3%) in Group-1 and 74 infants (66.7%) in Group-2. Na + and Cl^- levels of the AF of Group-1 were higher than Group 2 and this was statistically significant (p < .001/p: .01, respectively). Na⁺ and Cl^- levels of the AF were significantly higher in infants who needed surfactant (p < .001/p: .001, respectively).

CONCLUSION

Our results showed that Na⁺ and Cl^- levels of the AF can be used as an indicator of infant lung maturation.

Prenatal exposure to isolated amniotic fluid disorders and the risk for long-term endocrine morbidity of the offspring

BACKGROUND

Amniotic fluid abnormalities may be associated with adverse perinatal outcomes, some of which are endocrine related.

OBJECTIVE

To evaluate whether in utero exposure to amniotic fluid abnormalities is associated with long-term endocrine morbidity in the offspring.

STUDY DESIGN

In this cohort study, the incidence of long-term endocrine disorders was compared between singletons exposed and non-exposed to oligohydramnios or polyhydramnios.

RESULTS

During the study period, 195 943 newborns were included in the study, of them 2.0% (n = 4072) and 2.9% (n = 5684) were exposed to oligohydramnios and polyhydramnios, respectively. Long-term endocrine morbidity was higher among children exposed to isolated amniotic fluid disorders, as was also noted in the Kaplan-Meier survival curve (log-rank test p < 0.001). Abnormal amniotic fluid volume was found to be independently associated with long-term endocrine morbidity of the offspring according to a Cox regression model controlled for clinically related confounders.

CONCLUSION

In utero exposure to isolated amniotic fluid abnormalities is independently associated with long-term endocrine morbidity in the offspring.

Aquaporin 1 affects pregnancy outcome and regulates aquaporin 8 and 9 expressions in the placenta

To explore the effects of aquaporin (AQP) 1 on pregnancy outcome and the association between expression of AQP1 and other AQPs in the placenta and foetal membranes, the rate of copulatory plugs and pregnancy, amniotic fluid (AF) volume, osmolality and composition were determined in AQP1-knockout (AQP1^−/−) mice at different gestational days (GD). The expression and location of AQP1 and other AQPs in the placenta and foetal membranes of AQP1^−/− mice, AQP1-siRNA transfected WISH cells and oligohydramnios patients were also detected. Compared to control mice, AQP1^−/− mice exhibited reduced copulation plug and successful pregnancy rates, but these effects were accompanied by a larger AF volume and lower AF osmolality at late gestation. AQP9 expression was significantly decreased in the placenta and foetal membranes of AQP1^−/− mice, while AQP8 level was elevated in the foetal membranes of AQP1^−/− mice. Moreover, AQP9 expression was suppressed in WISH cells after AQP1 downregulation. Furthermore, AQP9 expression was associated with AQP1 level in the placenta and foetal membranes in oligohydramnios. AQP1 may play a critical role in regulating pregnancy outcome and maternal-foetal fluid homeostasis. Changes in AQP1 expression may lead to compensatory alterations in AQP8 and AQP9 expression in the placenta.

Lyophilization of human amniotic fluid is feasible without affecting biological activity

BACKGROUND

Fetal swallowing of human amniotic fluid (hAF) containing trophic factors (TFs) promotes gastrointestinal tract (GIT) development. Preterm birth interrupts hAF swallowing, which may increase the risk of necrotizing enterocolitis (NEC). Postnatally, it is difficult to replicate fetal swallowing of hAF due to volume. We aimed to evaluate whether hAF lyophilization is feasible and its effect on hAF-borne TFs.

METHODS

We collected hAF (n = 16) from uncomplicated pregnancies. hAF was divided into three groups: unprocessed control (C), concentration by microfiltration (F), and by dialysis and lyophilization (L). EGF, HGF, GM-CSF, and TGF-α were measured in each group by multiplex assay. Bioavailability of TFs was measured by proliferation and LPS-induced IL-8 production by intestinal epithelial cells FHs74.

RESULTS

After dialysis/lyophilization, GM-CSF and TGF-α were preserved with partial loss of EGF and HGF. hAF increased cell proliferation and reduced LPS-induced IL-8 production compared to medium alone. Compared to control, dialysis/lyophilization and filtration of hAF increased FHs74 cell proliferation (p < 0.001) and decreased LPS-induced IL-8 production (p < 0.01).

CONCLUSIONS

Lyophilization and filtration of hAF is feasible with partial loss of TFs but maintains and even improves bioavailability of TFs measured by proliferation and LPS-induced IL-8 production by FHs74.

Oligohydramnios: a prospective study of fetal, neonatal and maternal outcomes in low-middle income countries

Background

Oligohydramnios is a condition of abnormally low amniotic fluid volume that has been associated with poor pregnancy outcomes. To date, the prevalence of this condition and its outcomes has not been well described in low and low-middle income countries (LMIC) where ultrasound use to diagnose this condition in pregnancy is limited. As part of a prospective trial of ultrasound at antenatal care in LMICs, we sought to evaluate the incidence of and the adverse maternal, fetal and neonatal outcomes associated with oligohydramnios.

Methods

We included data in this report from all pregnant women in community settings in Guatemala, Pakistan, Zambia and the Democratic Republic of Congo (DRC) who received a third trimester ultrasound as part of the First Look Study, a randomized trial to assess the value of ultrasound at antenatal care. Using these data, we conducted a planned secondary analysis to compare pregnancy outcomes of women with to those without oligohydramnios. Oligohydramnios was defined as measurement of an Amniotic Fluid Index less than 5 cm in at least one ultrasound in the third trimester. The outcomes assessed included maternal morbidity and fetal and neonatal mortality, preterm birth and low-birthweight. We used pairwise site comparisons with Tukey-Kramer adjustment and multivariable logistic models using general estimating equations to account for the correlation of outcomes within cluster.

Results

Of 12,940 women enrolled in the clusters in Guatemala, Pakistan, Zambia and the DRC in the First Look Study who had a third trimester ultrasound examination, 87 women were diagnosed with oligohydramnios, equivalent to 0.7% of those studied. Prevalence of detected oligohydramnios varied among study sites; from the lowest of 0.2% in Zambia and the DRC to the highest of 1.5% in Pakistan. Women diagnosed with oligohydramnios had higher rates of hemorrhage, fetal malposition, and cesarean delivery than women without oligohydramnios. We also found unfavorable fetal and neonatal outcomes associated with oligohydramnios including stillbirths (OR 5.16, 95%CI 2.07, 12.85), neonatal deaths < 28 days (OR 3.18, 95% CI 1.18, 8.57), low birth weight (OR 2.10, 95% CI 1.44, 3.07) and preterm births (OR 2.73, 95%CI 1.76, 4.23). The mean birth weight was 162 g less (95% CI -288.6, − 35.9) with oligohydramnios.

Conclusions

Oligohydramnos was associated with worse neonatal, fetal and maternal outcomes in LMIC. Further research is needed to assess effective interventions to diagnose and ultimately to reduce poor outcomes in these settings.

Trial registration

NCT01990625.

Aquaporins during pregnancy

Aquaporins (AQPs) are water channels proteins that facilitate water flux across cell membranes in response to osmotic gradients. Despite of the differences in the mammalian placentas, the conserved combination of AQPs expressed in placental and fetal membranes throughout gestation suggests that these proteins may be important in the regulation of fetal water homeostasis. Thus, AQPs may regulate the amniotic fluid volume and participate in the trans-placental transfer of water. Apart from their classical roles, recent studies have revealed that placental AQPs may also cooperate in cellular processes such as the migration and the apoptosis of the trophoblasts. Aquaglyceroporins can also participate in the energy metabolism and in the urea elimination across the placenta. Many factors including oxygen, hormones, acid-basis homeostasis, maternal dietary status, interaction with other transport proteins and osmotic stress are proposed to regulate their expression and function during gestation and alterations result in pathological pregnancies.

Amniotic epithelial cells damage by oxidative stress in cases of diffuse chorioamniotic hemosiderosis

The amniotic membrane plays an important role in the physiological maintenance and protection of the embryo. Indeed, dysfunction of the amniotic membrane is thought to have an adverse effect on the continuation of pregnancy. In this report, we examined the pathological changes in the amniotic epithelium in three cases of diffuse chorioamniotic hemosiderosis (DCH) and investigated the cause of necrosis of the amniotic epithelial cells and its relationship with oligohydramnios. Diffuse chorioamniotic hemosiderosis was confirmed in all three cases. More extensive amniotic epithelial necrosis led to more severe hemosiderosis. Immunostaining for 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress, was positive in the amniotic epithelial cells. We speculate that oxidative DNA damage of the amniotic epithelium occurs by decomposition products of blood cells in cases accompanying subchorionic hematomas and pathological DCH. Furthermore, disorder of the amniotic epithelium may disrupt the balance of the amniotic fluid volume and cause oligohydramnios.

Early total enteral feeding in stable preterm infants: a systematic review and meta-analysis

OBJECTIVE

To evaluate safety and feasibility of early total enteral feeding (ETEF) in stable preterm infants.

STUDY DESIGN

Systematic review and meta-analysis of randomized trials comparing incidence of necrotizing enterocolitis (NEC) and feeding intolerance between ETEF and slow rates of enteral feed advancement.

RESULTS

Four trials involving 393 very low birth weight (VLBW) infants with birth weight >1000-1200 g were included. Meta-analyses did not show statistical difference in risks for NEC (RR 0.87, 95% CI 0.19-3.98) and feeding intolerance (RR 0.78, 95% CI 0.39-1.59). ETEF resulted in lower risk of late-onset sepsis (RR: 0.43, 95% CI: 0.30-0.61). Length of hospital stay was reduced in ETEF (mean difference -1.31 days, 95% CI: -1.54 to -1.07).

CONCLUSIONS

ETEF appears to be safe and feasible in stable VLBW infants with birth weight >1000-1200 g. A large randomized trial is needed to confirm benefits.

Preterm Premature Rupture of Membranes: A Review of 3 National Guidelines

Importance

Preterm premature rupture of membranes (PPROM) is a major cause of perinatal mortality and morbidity.

Objective

The aim of this study was to compare recommendations from published national guidelines for pregnancies complicated with PPROM.

Evidence Acquisition

A descriptive review of 3 national guidelines on PPROM was performed: the Royal College of Obstetricians and Gynaecologists on "Preterm Prelabour Rupture of Membranes," the American College of Obstetricians and Gynecologists on "Premature Rupture of Membranes," and the Society of Obstetricians and Gynaecologists of Canada on "Antibiotic Therapy in Preterm Premature Rupture of the Membranes." Guidelines were compared in the diagnosis and management of PPROM. Recommendations and strength of evidence were reviewed based on each guideline's method of reporting. The references were compared with regard to their total number, total number of randomized controlled trials, Cochrane reviews, and systematic reviews/meta-analyses cited.

Results

The variations stated on the guidelines reflect the heterogeneity of the literature contributing to the guidelines and challenges of diagnosing and managing cases of PPROM.

Conclusions

An improved international guideline may improve safety and outcomes in pregnant women with PPROM.

Loss of Aquaporin-3 in Placenta and Fetal Membranes Induces Growth Restriction in Mice

Aquaporin (AQP) 3, a facilitated transporter of water and glycerol, expresses in placenta and fetal membranes, but the detailed localization and function of AQP3 in placenta remain unclear. To elucidate a role of AQP3 in placenta, we defined the expression and cellular localization of AQP3 in placenta and fetal membranes, and investigated the structural and functional differences between wild-type and AQP3 null mice. Gestational sacs were removed during mid-gestational period and amniotic fluid was aspirated for measurements of volume and composition. Fetuses with attached placenta and fetal membranes were weighed and processed for histological assessment. AQP3 strongly expressed in basolateral membrane of visceral yolk sac cells of fetal membrane, the syncytiotrophoblasts of the labyrinthine placenta and fetal nucleated red blood cell membrane. Mice lacking AQP3 did not exhibit a significant defect in differentiation of trophoblast stem cells and normal placentation. However, AQP3 null fetuses were smaller than their control litter mates in spite of a decrease in litter size. The total amniotic fluid volume per gestational sac was reduced, but the amniotic fluid-to-fetal weight ratio was increased in AQP3 null mice compared with wild-type mice. Glycerol, free fatty acid and triglyceride levels in amniotic fluid of AQP3 null mice were significantly reduced, whereas lactate level increased when compared to those of wild-type mice. These results suggest a role for AQP3 in supplying nutrients from yolk sac and maternal blood to developing fetus by facilitating transport of glycerol in addition to water, and its implication for the fetal growth in utero.

Gastric fluid used to assess changes during the latency period in preterm prelabor rupture of membranes

OBJECTIVE

To determine changes in the intraamniotic environment during the latency period using paired amniotic and gastric fluid samples in pregnancies complicated by preterm prelabor rupture of membranes (PPROM).

METHODS

A total of 34 women with singleton pregnancies complicated by PPROM prior to 34 weeks were included in the study. Amniotic fluid was obtained by transabdominal amniocentesis at the time of admission. Immediately after delivery, umbilical cord blood and gastric fluid were obtained.

RESULT

Microorganisms in amniotic and gastric fluid samples were found in 38% and 59% of women, respectively. Bedside IL-6 levels were higher in amniotic than in gastric fluid in pregnancies without fetal inflammatory response syndrome (FIRS) (263 pg/mL vs. 50 pg/mL; p < 0.0001), but not in pregnancies with FIRS (318 pg/mL vs. 444 pg/mL; p = 0.91). Funisitis and FIRS was associated with the highest bedside IL-6 levels in gastric fluid. A gastric fluid bedside IL-6 level of 275 pg/mL was found to be the ideal cutoff value to predict funisitis and FIRS.

CONCLUSIONS

The microbial and inflammatory status of the intraamniotic compartment changes during the latency period in PPROM. Bedside IL-6 assessment of gastric fluid may be useful in the rapid diagnosis of funisitis and FIRS.

Are Congenital Urinary Tract Abnormalities Linked to Maternal Methylenetetrahydrofolate Reductase Polymorphisms in Fetuses of Intentionally Terminated Pregnancies with Oligo- or Anhydramnios ?

OBJECTIVE

We aimed to evaluate fetuses of terminated pregnancies with oligo-or anhydramnios (OAH) to further investigate the association between maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms and fetal urinary tract malformations.

MATERIALS AND METHODS

This retrospective study included 16 pregnancies with OAH (with normal fetal karyotype) that were intentionally terminated before 22nd gestational week. Fetal autopsy was performed in all cases. We evaluated cases for presence of DNA methylation pathway-related gene polymorphisms.

RESULTS

We demonstrated that renal abnormalities and disorders exist in 75% of the cases. Pulmonary system anomalies and single umbilical artery were the most frequently observed associated abnormalities. Polymorphisms with known reduced MTHFR activity were found in 81.8% (9/11) of the cases.Association between urinary system abnormalities and polymorphisms with known reduced MTHFR activity was observed in 88.8% (8/9) of the cases.

CONCLUSION

Physicians should keep in mind that polymorphisms with known reduced MTHFR activity may be associated with urinary tract abnormalities and OAH.

The matter of the reproductive microbiome

The preconceptional presence of microbiota in the female and male reproductive organs suggests that fertilization is taking place in a nonsterile environment and contributes to reproductive success. The concept of embryonic development in a sterile uterus has also been challenged with recent reports of the existence of a microbiome of the placenta, amniotic fluid and the fetal gut in normal, uncomplicated pregnancies. The maternal origins of the microbiota colonising the fetus and its surroundings are unknown as are the mechanisms of maternal-to-fetal transfer. In this review, we aim to highlight the preconception male and female microbiome, the maternal vaginal and gut microbiome during pregnancy and the fetal microbiome, including their possible roles in reproduction, and maternal and neonatal pregnancy outcome.

The immunophenotype of amniotic fluid leukocytes in normal and complicated pregnancies

PROBLEM

The immune cellular composition of amniotic fluid is poorly understood. Herein, we determined: 1) the immunophenotype of amniotic fluid immune cells during the second and third trimester in the absence of intra-amniotic infection/inflammation; 2) whether amniotic fluid T cells and ILCs display different phenotypical characteristics to that of peripheral cells; and 3) whether the amniotic fluid immune cells are altered in women with intra-amniotic infection/inflammation.

METHOD OF STUDY

Amniotic fluid samples (n = 57) were collected from 15 to 40 weeks of gestation in women without intra-amniotic infection/inflammation. Samples from women with intra-amniotic infection/inflammation were also included (n = 9). Peripheral blood mononuclear cells from healthy adults were used as controls (n = 3). Immunophenotyping was performed using flow cytometry.

RESULTS

In the absence of intra-amniotic infection/inflammation, the amniotic fluid contained several immune cell populations between 15 and 40 weeks. Among these immune cells: (i) T cells and ILCs were greater than B cells and natural killer (NK) cells between 15 and 30 weeks; (ii) T cells were most abundant between 15 and 30 weeks; (iii) ILCs were most abundant between 15 and 20 weeks; (iv) B cells were scarce between 15 and 20 weeks; yet, they increased and were constant after 20 weeks; (v) NK cells were greater between 15 and 30 weeks than at term; (vi) ILCs expressed high levels of RORγt, CD161, and CD103 (ie, group 3 ILCs); (vii) T cells expressed high levels of RORγt; (viii) neutrophils increased as gestation progressed; and (ix) monocytes/macrophages emerged after 20 weeks and remained constant until term. All of the amniotic fluid immune cells, except ILCs, were increased in the presence of intra-amniotic infection/inflammation.

CONCLUSION

The amniotic fluid harbors a diverse immune cellular composition during normal and complicated pregnancies.

Amniotic fluid oxidant-antioxidant status in foetal congenital nervous system anomalies

Objective

This study aimed to evaluate the oxidant–antioxidant status of amniotic fluid in pregnant women with foetal congenital malformations of the central nervous system.

Methods

We studied pregnant women with foetal congenital nervous system anomalies at 16–22 weeks’ gestation (n = 36). The control group (n = 30) consisted of pregnant women at the same gestational age who underwent amniocentesis, resulting in a normal karyotype. We analysed glutathione, catalase, and malondialdehyde levels in amniotic fluid. Enzyme activation was measured by spectrophotometry.

Results

The demographic features of the groups were similar in terms of age, parity, body mass index, and gestational weeks. We detected lower glutathione and catalase levels in the foetal congenital anomaly group than in the control group. We detected higher malondialdehyde levels in the foetal congenital anomaly group than in the control group.

Conclusion

In the organism, the rate of formation of free radicals and their rate of removal are balanced, and this is called oxidative balance. As long as oxidative stability is achieved, the organism is not affected by free radicals. This fact should be kept in mind to avoid any type of teratogenic agent that could lead to congenital disorders.

Prenatal androgen exposure and children's aggressive behavior and activity level

Some human behaviors, including aggression and activity level, differ on average for males and females. Here we report findings from two studies investigating possible relations between prenatal androgen and children's aggression and activity level. For study 1, aggression and activity level scores for 43 girls and 38 boys, aged 4 to 11years, with congenital adrenal hyperplasia (CAH, a genetic condition causing increased adrenal androgen production beginning prenatally) were compared to those of similarly-aged, unaffected relatives (41 girls, 31 boys). Girls with CAH scored higher on aggression than unaffected girls, d=0.69, and unaffected boys scored higher on activity level than unaffected girls, d=0.50. No other group differences were significant. For study 2, the relationship of amniotic fluid testosterone to aggression and activity level was investigated in typically-developing children (48 girls, 44 boys), aged 3 to 5years. Boys scored higher than girls on aggression, d=0.41, and activity level, d=0.50. However, amniotic fluid testosterone was not a significant predictor of aggression or activity level for either sex. The results of the two studies provide some support for an influence of prenatal androgen exposure on children's aggressive behavior, but not activity level. The within-sex variation in amniotic fluid testosterone may not be sufficient to allow reliable assessment of relations to aggression or activity level.

Protective effects of amniotic fluid in the setting of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common life threatening condition affecting preterm infants. NEC occurs in 1-5% of all neonatal intensive care admissions and 5-10% of very low birth weight infants. The protective role of human breast milk (BM) has been well established. It has also been shown that amniotic fluid (AF) and BM have many similarities in terms of presence of growth and other immune-modulatory factors. This finding led to the initial hypothesis that AF may exert similar protective effects against the development of NEC, as does BM. Multiple studies have elucidated the presence of growth factors in AF and the protective effect of AF against NEC. Studies have also described possible mechanisms how AF protects against NEC. At present, research in this particular area is extremely active and robust. This review summarizes the various studies looking at the protective effects of AF against the development of NEC. It also provides an insight into future directions, the vast potential of AF as a readily available biologic medium, and the ethical barriers that must be overcome before using AF.

Impact of antepartum diagnostic amnioinfusion on targeted ultrasound imaging of pregnancies presenting with severe oligo- and anhydramnios: An analysis of 61 cases

OBJECTIVES

The primary objective our study was to assess the role of diagnostic antepartum amnioinfusion on the yield from targeted ultrasounds performed in pregnancies with severe oligo- and anhydramnios.

STUDY DESIGN

This was a retrospective and descriptive study, conducted in the fetal medicine units of two private tertiary care referral centers in south India. The details of all the cases of diagnostic amnioinfusion performed at these two centers from January 2009 to June 2016 were collected and analyzed. Inclusion criteria were pregnancies between 17 and 26 weeks of gestational age with severe oligo- or anhydramnios. Pregnancies with obvious preterm premature rupture of membranes (PPROM) were excluded. The primary outcome measure was the improvement in diagnostic information pertaining to cause of severe oligo- and anhydramnios, and the nature of such anomalies.

RESULTS

A total of 61 cases of were identified. The median gestational age at performance of the procedure was 22 weeks [IQR, 19.5-23]. The mean volume of normal saline infused was 314±54ml. A significant increase in the single vertical pocket (SVP) was observed following the procedure (pre-procedure SVP=0.6±0.9cm, post procedure SVP=3.4±1.7; paired t test, p<0.001). In 37 cases (37/61, 60.7%), there were no pre-procedure ultrasound findings. There was significant overall detection of abnormalities post procedure (mean pre-procedure findings=0.39±0.49, mean post procedure findings=1.59±1.24; paired t test, p<0.001). The most frequent group of anomalies/abnormalities were renal (36/61, 59%), followed by PPROM (13/61, 21.3%) and finally fetal growth restriction (11/61, 18%).

CONCLUSION(S)

Antepartum amnioinfusion is a valuable ancillary technique in prenatal diagnosis as it increases the diagnostic yield from pregnancies presenting with severe oligo- and anhydramnios.

Highly potent stem cells from full-term amniotic fluid: A realistic perspective

Amniotic fluid (AF) is now known to harbor highly potent stem cells, making it an excellent source for cell therapy. However, most of the stem cells isolated are from AF of mid-term pregnancies in which the collection procedure involves an invasive technique termed amniocentesis. This has limited the access in getting the fluid as the technique imposes certain level of risks to the mother as well as to the fetus. Alternatively, getting AF from full-term pregnancies or during deliveries would be a better resolution. Unfortunately, very few studies have isolated stem cells from AF at this stage of gestation, the fluid that is merely discarded. The question remains whether full-term AF harbors stem cells of similar potency as of the stem cells of mid-term AF. Here, we aim to review the prospect of having this type of stem cells by first looking at the origin and contents of AF particularly during different gestation period. We will then discuss the possibility that the AF, at full term, contains a population of highly potent stem cells. These stem cells are distinct from, and probably more potent than the AF mesenchymal stem cells (AF-MSCs) isolated from full-term AF. By comparing the studies on stem cells isolated from mid-term versus full-term AF from various species, we intend to address the prospect of having highly potent amniotic fluid stem cells from AF of full-term pregnancies in human and animals.

Rapid test for lung maturity, based on spectroscopy of gastric aspirate, predicted respiratory distress syndrome with high sensitivity

AIM

Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in premature infants. By the time symptoms appear, it may already be too late to prevent a severe course, with bronchopulmonary dysplasia or mortality. We aimed to develop a rapid test of lung maturity for targeting surfactant supplementation.

METHODS

Concentrations of the most surface-active lung phospholipid dipalmitoylphosphatidylcholine and sphingomyelin in gastric aspirates from premature infants were measured by mass spectrometry and expressed as the lecithin/sphingomyelin ratio (L/S). The same aspirates were analysed with mid-infrared spectroscopy. Subsequently, L/S was measured in gastric aspirates and oropharyngeal secretions from another group of premature infants using spectroscopy and the results were compared with RDS development. The 10-minute analysis required 10 μL of aspirate.

RESULTS

An L/S algorithm was developed based on 89 aspirates. Subsequently, gastric aspirates were sampled in 136 infants of 24-31 weeks of gestation and 61 (45%) developed RDS. The cut-off value of L/S was 2.2, sensitivity was 92%, and specificity was 73%. In 59 cases, the oropharyngeal secretions had less valid L/S than gastric aspirate results.

CONCLUSION

Our rapid test for lung maturity, based on spectroscopy of gastric aspirate, predicted RDS with high sensitivity.

Antisense oligonucleotides delivered to the amniotic cavity in utero modulate gene expression in the postnatal mouse

Congenital diseases account for a large portion of pediatric illness. Prenatal screening and diagnosis permit early detection of many genetic diseases. Fetal therapeutic strategies to manage disease processes in utero represent a powerful new approach for clinical care. A safe and effective fetal pharmacotherapy designed to modulate gene expression ideally would avoid direct mechanical engagement of the fetus and present an external reservoir of drug. The amniotic cavity surrounding the fetus could serve as an ideal drug reservoir. Antisense oligonucleotides (ASOs) are an established tool for the therapeutic modulation of gene expression. We hypothesize that ASOs administered to the amniotic cavity will gain entry to the fetus and modulate gene expression. Here, we show that an ASO targeting MALAT1 RNA, delivered by transuterine microinjection into the mouse amniotic cavity at embryonic day 13-13.5, reduces target RNA expression for up to 4 weeks after birth. A similarly delivered ASO targeting a causal splice site mutation for Usher syndrome corrects gene expression in the inner ear, a therapeutically relevant target tissue. We conclude that intra-amniotic delivery of ASOs is well tolerated and produces a sustained effect on postnatal gene expression. Transuterine delivery of ASOs is an innovative platform for developing fetal therapeutics to efficaciously treat congenital disease.

Amniotic fluid: Source of trophic factors for the developing intestine

The gastrointestinal tract (GIT) is a complex system, which changes in response to requirements of the body. GIT represents a barrier to the external environment. To achieve this, epithelial cells must renew rapidly. This renewal of epithelial cells starts in the fetal life under the influence of many GIT peptides by swallowing amniotic fluid (AF). Development and maturation of GIT is a very complex cascade that begins long before birth and continues during infancy and childhood by breast-feeding. Many factors like genetic preprogramming, local and systemic endocrine secretions and many trophic factors (TF) from swallowed AF contribute and modulate the development and growth of the GIT. GIT morphogenesis, differentiation and functional development depend on the activity of various TF in the AF. This manuscript will review the role of AF borne TF in the development of GIT.

The fetal brain sparing response to hypoxia: physiological mechanisms

How the fetus withstands an environment of reduced oxygenation during life in the womb has been a vibrant area of research since this field was introduced by Joseph Barcroft, a century ago. Studies spanning five decades have since used the chronically instrumented fetal sheep preparation to investigate the fetal compensatory responses to hypoxia. This defence is contingent on the fetal cardiovascular system, which in late gestation adopts strategies to decrease oxygen consumption and redistribute the cardiac output away from peripheral vascular beds and towards essential circulations, such as those perfusing the brain. The introduction of simultaneous measurement of blood flow in the fetal carotid and femoral circulations by ultrasonic transducers has permitted investigation of the dynamics of the fetal brain sparing response for the first time. Now we know that major components of fetal brain sparing during acute hypoxia are triggered exclusively by a carotid chemoreflex and that they are modified by endocrine agents and the recently discovered vascular oxidant tone. The latter is determined by the interaction between nitric oxide and reactive oxygen species. The fetal brain sparing response matures as the fetus approaches term, in association with the prepartum increase in fetal plasma cortisol, and treatment of the preterm fetus with clinically relevant doses of synthetic steroids mimics this maturation. Despite intense interest into how the fetal brain sparing response may be affected by adverse intrauterine conditions, this area of research has been comparatively scant, but it is likely to take centre stage in the near future.

What is the role of amnioinfusion in modern day obstetrics?

Amniotic fluid (AF) is a dynamic medium that plays a significant role in fetal well-being. It is production and amount varies with gestational age. It plays a vital role in fetal life as it contains antimicrobial factors, growth factors and it help the fetal lung to grow and expand. Amnioinfusion can be performed either transabdominally or transvaginal. Amnioinfuion can be done antenatally and during labor. Aminoinfusion can be used for diagnostic purposes to enable better visualization of the fetus as liquor is very important acoustic widow for better fetal examination. Amnioinfusion have some therapeutic benefits in conditions like early premature rupture of membrane and may help cases of external cephalic version for breech presentation at term. Amnioinfusion has been shown to reduce the incidence of variable deceleration due to cord compression, reduces the risk of meconium aspiration and it will help reduce cesarean delivery.