Amnioinfusion for 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 (30 September 2011).

SELECTION CRITERIA

Randomised trials of amnioinfusion compared to 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 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.

Successful management of a high-risk pregnancy with polyhydramnios, IUGR and recurrent pregnancy loss in a chronic renal failure patient: a case report

Pregnancy in patients with chronic renal failure occurs rarely but the incidence is increasing. The successful management of a 38-year-old woman suffering from chronic renal failure is discussed.

Effect of bovine amniotic fluid on intra-abdominal adhesion in diabetic male rats

BACKGROUND

Postsurgical adhesion formation is a significant clinical problem within every surgical specialty. In type I diabetic patients, the problem is more severe and wound healing is slow. A wide variety of treatments have been proposed to deal with the problems that adhesion causes. One of the modalities that have not been studied extensively yet is the use of amniotic fluid. The purpose of the present study was to evaluate the clinical value of bovine amniotic fluid (BAF) efficacy in the treatment of postsurgical adhesion formation in diabetic male rats.

MATERIALS AND METHODS

Fifty male Wistar rats in five groups were used for our study, with animal identification being facilitated by a microchip implant system. Diabetes was induced in all groups except for the control group by intraperitoneal alloxan injection (120 mg/kg). Based upon blood glucose concentration, rats received either one third of the required insulin (two groups) or all the required insulin (remaining groups). After 2 weeks, a laparotomy was performed on each rat and adhesions were scaled. Bovine amniotic fluid was then applied to two groups, and, as a control, sterilized water was applied to the other groups. After 2 weeks, a laparotomy was again performed on each rat and adhesion was rescored.

RESULTS AND CONCLUSION

Significant reductions (P<.05) in adhesions were seen with BAF only in those diabetic rats that had received the required insulin. The results of our study suggest that BAF could be effective in the treatment of adhesion formation during diabetes.

Human amniocytes regulate serotonin levels by active uptake and express genes suggestive of a wider role in facilitating neurotransmitter regulation in the fetal environment

Fetal serotonin levels, which mediate multiple developmental processes, are highly regulated. However, an incomplete picture exists on the component parts of such regulation during fetal growth. Serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) are found in the amniotic fluid, also containing significant numbers of amniocytes, previously thought to be the result of cell shedding as a byproduct of growth. The aim of the present study was to examine human amniocytes as a potentially active and dynamic component of serotonin regulation in the fetal environment. Using amniocytes derived from multiple donors of amniocentesis, we found all components necessary for serotonin metabolism. We identified a strong expression of the serotonin transporter and confirmed the high-affinity serotonin transporter-mediated uptake of serotonin (5-HT), along with uptake via the norepinephrine transporter, and an evidence of 5-HT breakdown due to the expression of the degradative enzymes monoamine oxidase A and B. Additionally, wider expression analysis for biogenic amine and cholinergic metabolism suggests a capability for cholinergic synthesis and release and for catecholamine storage. Our results shed new light on amniocytes, consistent with a role in the homeostasis of neurotransmitters during fetal development. Moreover, these results may provide clinical significance for amniocytes as new targets for uptake inhibitors such as tricyclic antidepressants, selective serotonin reuptake inhibitors, and drugs of abuse such as cocaine, with implications on their regulation during pregnancy. This work shows for the first time an inherent in vivo function of amniocytes and more broadly implicates them as a new and active component of the fetal-maternal regulatory system.

Clinical significance of early (< 20 weeks) vs. late (20-24 weeks) detection of sonographic short cervix in asymptomatic women in the mid-trimester

OBJECTIVE

The aim of this study was to determine whether the risk of early spontaneous preterm delivery (PTD) in asymptomatic women with a sonographic cervical length of ≤ 15 mm in the mid-trimester changes as a function of gestational age at diagnosis.

METHODS

This cohort study included 109 asymptomatic patients with a sonographic cervical length of ≤ 15 mm diagnosed at 14-24 weeks of gestation. Women with a multifetal gestation, cerclage and a cervical dilatation of > 2 cm were excluded. The study population was stratified by gestational age at diagnosis (< 20 weeks vs. 20-24 weeks) and by cervical length (≤ 10 mm vs. 11-15 mm). The primary outcome variables were PTD at < 28 and < 32 weeks of gestation and the diagnosis-to-delivery interval.

RESULTS

The median gestational age at diagnosis of a short cervix before 20 weeks and at 20-24 weeks was 18.9 and 22.7 weeks, respectively. Women diagnosed before 20 weeks had a higher rate of PTD at < 28 weeks (76.9% vs. 30.9%; P < 0.001) and at < 32 weeks (80.8% vs. 48.1%; P = 0.004), and a shorter median diagnosis-to-delivery interval (21 vs. 61.5 days, P = 0.003) than those diagnosed at 20-24 weeks. The rate of amniotic fluid sludge was higher among patients diagnosed with a short cervix at < 20 weeks of gestation than in those in whom it was diagnosed between 20 and 24 weeks (92.3% vs. 48.2%; P < 0.001).

CONCLUSIONS

Asymptomatic women with a sonographic cervical length of ≤ 15 mm diagnosed before 20 weeks of gestation have a dramatic and significantly higher risk of early preterm delivery than women diagnosed at 20-24 weeks. These findings can be helpful to physicians in counseling these patients, and may suggest different mechanisms of disease leading to a sonographic short cervix before or after 20 weeks of gestation.

Clinical implication of intra-amniotic sludge on ultrasound in patients with cervical cerclage

OBJECTIVE

The aim of this study was to determine whether intra-amniotic (IA) sludge, a sonographic finding of hyperechoic matter in the amniotic fluid close to the internal cervical os, is associated with preterm delivery in patients with cervical cerclage.

METHODS

A retrospective cohort study of patients who had undergone McDonald cerclage between January 1997 and December 2004 was conducted. Transvaginal ultrasound examinations had been performed at 14-28 weeks of gestation, and the ultrasound images were assessed by three reviewers (blinded to patient outcome) to determine the presence or absence of IA sludge. The primary outcome studied was the gestational age at delivery.

RESULTS

A total of 177 patients who had undergone cervical cerclage, and for whom adequate records were available, were identified. Sixty had sonographic evidence of IA sludge (Group 1) and 117 had absence of IA sludge (Group 2). There was no significant difference in the mean gestational age at delivery between the two groups (36.4 ± 4.0 vs. 36.8 ± 2.9 weeks, P = 0.53), and no statistical difference in the rate of preterm delivery at < 28 (6.7% vs. 1.7%, P = 0.18), < 30 (6.7% vs. 3.4%, P = 0.45), < 32 (8.3% vs. 6.8%, P = 0.77) or < 36 (16.7% vs. 19.7%, P = 0.69) weeks of gestation.

CONCLUSION

Intra-amniotic sludge on ultrasound is not associated with an increased risk of preterm delivery in patients with cervical cerclage.

Neonatal outcome in meconium stained amniotic fluid-one year experience

OBJECTIVES

To determine the effect of clear liquor and meconium stained liquor on mode of delivery, and to evaluate neonatal outcome.

METHODS

It was a Cross sectional analytical study, conducted in the department of Obstetrics and Gynaecology, Shaikh Zyed Federal Postgraduate Medical Institute/Hospital, Lahore and Shaikh Zaid Women Hospital Larkana, from April 2006 to March 2007. Two hundred and fifty patients from Larkana and 250 patients from Lahore in clear liquor group were included in the study. Similarly 125 patients from each city, that is 250 patients which had meconium stained liquor were included in group 2. The subjects with meconium stained amniotic fluid and clear amniotic fluid were registered as group 1 and 2. The socio demographic information, fertility history and gestational age of subjects were recorded. The investigations and information regarding mode of delivery and duration of labour were also noted. All babies delivered were attended by paediatricians.

RESULTS

In this study 500 cases with clear liquor and 250 cases of meconium stained liquor were selected from two cities, Lahore and Larkana. Out of these 55 (22%) patients had grade I meconium stained liquor, 140 (56%) patients and 55 (22%) patients had grade II and grade III meconium stained liquor respectively. The mode of delivery is significantly affected by meconium staining of liquor. The effect of meconium stained liquor was significant on time of delivery. There were 40 (16%) post date deliveries in meconium stained liquor as compared to 1% in subjects with clear liquor. The effect of meconium staining of liquor was significant on Apgar score, neonatal admission, meconium aspiration syndrome and neonatal deaths.

CONCLUSION

Meconium stained amniotic fluid (MSAF), is associated with increased neonatal morbidity and mortality. Caesarean sections were performed twice as frequently in women presenting with MSAF.

Measurement of fetal urine production to differentiate causes of increased amniotic fluid volume

OBJECTIVES

In polyhydramnios, amniotic fluid (AF) volume can be increased not only as a result of increased fetal urine production, but also due to several other factors, including impairment of both fetal swallowing and gastrointestinal (GI) absorption of AF. Our aim was to evaluate whether measurement of the fetal urine production rate (UPR) can be used to differentiate the causes of increased AF volume.

METHODS

This cross-sectional study included 54 pregnant women with an increased amniotic fluid index (AFI), defined as AFI > or = 18 cm, divided into two groups according to the presence of fetal anomalies that are associated with impairment of fetal swallowing or decreased GI absorption of AF (Group 1, n = 14) or the absence of fetal anomalies (Group 2, n = 40). The control group included 96 normal pregnancies with normal AFI (8 < or = AFI < 18 cm) (Group 3). Fetal UPR was obtained by serial bladder volume measurements (two to four times, with a median interval of 5 min between each) using the rotational method of Virtual Organ Computer-aided AnaLysis (VOCAL()) with three-dimensional ultrasound. To adjust for fetal weight (Wt) and gestational age (GA), UPR_Wt and UPR_SD were calculated using the following formulae: UPR_Wt = measured UPR/estimated fetal weight and UPR_SD = (measured UPR - mean UPR for each GA)/SD of UPR for each GA.

RESULTS

The AFI was increased significantly in Groups 1 and 2 compared with Group 3. However, the median fetal UPR in Group 1 did not differ from that of Group 3, in contrast to the higher median fetal UPR in Group 2 compared with Groups 1 and 3; this difference remained significant after adjusting for GA and estimated fetal weight in terms of UPR_SD and UPR_Wt. In Groups 2 and 3, AFI and UPR had a positive correlation in terms of UPR, UPR_SD and UPR_Wt.

CONCLUSIONS

Our findings that fetal UPR is significantly increased in cases with increased AFI without fetal anomalies, but not in those with increased AFI and fetal anomalies involving decreased GI absorption of AF, might be used to differentiate causes of increased AF volume. In the absence of fetal anomalies, AFI and fetal UPR correlate positively.

[Aquaporins and the regulation of amniotic fluid circulation]

OBJECTIVE

The purpose of this study was to focuse on aquaporins and their role in the regulation of amniotic fluid circulation.

DESIGN

Review.

SETTING

Department of Obstetrics and Gynecology Medical Faculty Charles University Hradec Kralove.

METHODS

The summary about aquaporins which were first described as channels increased permeability of lipid membranes to water in response to osmotic and/or hydrostatic gradients.

CONCLUSION

The present review summarizes the results of clinical and experimental research on aquaporins and the regulation of amniotic fluid circulation.

Potential function of amniotic fluid in fetal development---novel insights by comparing the composition of human amniotic fluid with umbilical cord and maternal serum at mid and late gestation

BACKGROUND

Amniotic fluid (AF) is a dynamic and complex mixture. Up to now, little is known about the physiological functions of AF in the process of fetal development. We suppose that AF carries components such as proteins or peptides, which contribute to the regulation of fetal development.

METHODS

Compositions including biochemical components and tumor markers were determined in human AF, umbilical cord serum (UCS) and maternal serum (MS) from the same subject in the range of 15-42 weeks of gestation.

RESULTS

(1) The levels of primary electrolytes such as sodium, chloride, anion gap and osmotic pressure in AF was almost the same as in UCS and MS. (2) The levels of organic substances, including total protein, glucose, triglycerides, cholesterol and various enzymes, were markedly lower in AF than in UCS and MS, especially for total protein, which was 8- and 12.5-fold lower in AF than in UCS and MS, respectively. (3) The levels of tumor markers, including carcinoembryonic antigen, ferritin, cancer antigen 125 and 199, and alpha-fetoprotein in AF displayed different dynamic changes compared to UCS and MS as gestation advanced.

CONCLUSION

This study demonstrated that AF is not a result of simple filtration from the blood but an independent fluid. We speculate that proteins or peptides in the amniotic fluid modulate the process of fetus development since they possess potent bioactivity on cellular growth and proliferation. AF provides a pathway to transport these "regulators" to the fetus and thus plays a pivotal role in fetal development.

Intramembranous solute and water fluxes during high intramembranous absorption rates in fetal sheep with and without lung liquid diversion

OBJECTIVE

To examine mechanisms that mediate increased intramembranous solute and water absorption.

STUDY DESIGN

Intramembranous solute and water fluxes were measured in fetal sheep under basal conditions and after intraamniotic infusion of lactated Ringer's solution of 4 L/d for 3 days with and without lung liquid diversion.

RESULTS

Intramembranous sodium, potassium, chloride, calcium, glucose, and lactate fluxes increased 2.5- to 7.9-fold, were linearly related to volume fluxes (r = 0.83-0.99), and were unaffected by lung liquid. All clearance rates, except that of lactate, increased to equal the intramembranous volume absorption rate during infusion.

CONCLUSION

Under basal conditions, passive diffusion makes a minor and bulk flow a major contribution to intramembranous solute absorption. During high absorption rates, the increase in solute absorption above basal levels appears to be due entirely to bulk flow and is unaffected by lung liquid. The increased bulk flow is consistent with vesicular transcytosis.

Prenatal sex hormones (maternal and amniotic fluid) and gender-related play behavior in 13-month-old Infants

Testosterone, estradiol, and progesterone levels were measured in the second trimester of pregnancy in maternal serum and amniotic fluid, and related to direct observations of gender-related play behavior in 63 male and 63 female offspring at age 13 months. During a structured play session, sex differences in toy preference were found: boys played more with masculine toys than girls (d = .53) and girls played more with feminine toys than boys (d = .35). Normal within-sex variation in prenatal testosterone and estradiol levels was not significantly related to preference for masculine or feminine toys. For progesterone, an unexpected significant positive relationship was found in boys between the level in amniotic fluid and masculine toy preference. The mechanism explaining this relationship is presently not clear, and the finding may be a spurious one. The results of this study may indicate that a hormonal basis for the development of sex-typed toy preferences may manifest itself only after toddlerhood. It may also be that the effect size of this relationship is so small that it should be investigated with more sensitive measures or in larger populations.

Meconium-stained amniotic fluid and meconium aspiration syndrome: a prospective study

BACKGROUND

The incidence of meconium aspiration syndrome (MAS), associated perinatal factors, morbidity and deaths varies widely. This study aimed to assess the perinatal attributes and morbidity associated with MAS.

METHODS

Over a 2-year period, all neonates born through meconium-stained amniotic fluid (MSAF) were observed for respiratory distress (RD). Birth details, chest radiograph (CXR) and clinical course were documented. Neonates with consistent CXR findings whose RD could not otherwise be explained were defined as MAS.

RESULTS

Of 409 neonates born through MSAF, meconium was thick in 196 (47.9%). Fifty-five (13.4%) had RD and 45 (11.3%) were consistent with MAS. Six (1.5%) neonates died. Mean (SD) birthweight and gestation of MAS infants were 2721.9 (510.2) g and 38.67 (1.09) weeks, respectively. About one-third were of low birthweight and 28 were born by caesarean section. On univariate analysis, caesarean delivery, meconium in the trachea and thick meconium were the significant perinatal factors for the development of MAS. On multiple regression analysis, thick meconium was the only independent factor for MAS (OR 7.08, 95% CI 3.08-16.27, p<0.001). An Apgar score of <or=6 and blood gas abnormalities were found in 44.4% and 48.9%, respectively. Air leak syndrome was observed in 12 (26.7%), persistent pulmonary hypertension in seven and severe asphyxia and late sepsis in two each. Thirteen (28.9%) required mechanical ventilation and six (13.3%) died.

CONCLUSION

MAS occurred in 11.3% of neonates born through MSAF. Thick meconium was found to be an important causative factor. Nearly one-third of infants with MAS required mechanical ventilation and 13.3% died.

Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome

BACKGROUND

Amniotic fluid volume is an important parameter in the assessment of fetal well-being. Oligohydramnios occurs in many high-risk conditions and is associated with poor perinatal outcomes. Many caregivers practice planned delivery by induction of labor or caesarean section after diagnosis of decreased amniotic fluid volume at term. There is no clear consensus on the best method to assess amniotic fluid adequacy.

OBJECTIVES

To compare the use of the amniotic fluid index with the single deepest vertical pocket measurement as a screening tool for decreased amniotic fluid volume in preventing adverse pregnancy outcome.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2), MEDLINE (1966 to May 2007) and the metaRegister of Controlled Trials (May 2007). We handsearched the citation lists of relevant publications, review articles, and included studies.

SELECTION CRITERIA

Randomised controlled trials involving women with a singleton pregnancy, whether at low or high risk, undergoing ultrasound measurement of amniotic fluid volume as part of antepartum assessment of fetal well-being that compared the amniotic fluid index and the single deepest vertical pocket measurement.

DATA COLLECTION AND ANALYSIS

Both authors independently assessed eligibility and quality, and extracted the data.

MAIN RESULTS

Four trials (3125 women) met the inclusion criteria. There is no evidence that one method is superior to the other in the prevention of poor peripartum outcomes, including: admission to a neonatal intensive care unit; an umbilical artery pH of less than 7.1; the presence of meconium; an Apgar score of less than 7 at five minutes; or caesarean delivery. When the amniotic fluid index was used, significantly more cases of oligohydramnios were diagnosed (risk ratio (RR, random) 2.33, 95% CI 1.67 to 3.24), and more women had inductions of labor (RR (fixed) 2.10, 95% CI 1.60 to 2.76) and caesarean delivery for fetal distress (RR (fixed) 1.45, 95% CI 1.07 to 1.97).

AUTHORS' CONCLUSIONS

The single deepest vertical pocket measurement in the assessment of amniotic fluid volume during fetal surveillance seems a better choice since the use of the amniotic fluid index increases the rate of diagnosis of oligohydramnios and the rate of induction of labor without improvement in peripartum outcomes. A systematic review of the diagnostic accuracy of both methods in detecting decreased amniotic fluid volume is required.

Prospective full-term-derived pluripotent amniotic fluid stem (AFS) cells

Amniotic fluid (AF) serves as an excellent alternative source of pluripotent stem cells, as they are not bound with ethical issues and the stem cells are more primitive than adult stem (AS) cells. Hence, they have higher potential. Here we aim to isolate and characterize pluripotent stem cells from mid-term and full-term pregnant rat amniotic fluid. The results demonstrate the evidence of heterogeneous population of cells in the amniotic fluid and some of the cells morphology shows similarity with ES cells.

Relationship of IL-6, IL-8, TNF and sICAM-1 levels to PROM, pPROM, and the risk of early-onset neonatal sepsis

BACKGROUND

Intraamniotic infections negatively affect the mortality and morbidity in parturients and newborns. The prognosis of the disease is associated with a timely diagnosis of these conditions. One of approaches to providing timely information on the risk of the initiation of intra-amniotic infection and early-onset neonatal sepsis is the examination of cytokine levels.

OBJECTIVES

The purpose of the work was to evaluate the importance of the cytokines, IL-6, IL-8, and TNF-alpha, and the adhesive molecule, sICAM-1, as risk factors for early-onset neonatal sepsis and intra-amniotic infections.

METHODS

In a group of 152 women we sampled the blood from the umbilical cord vein immediately after delivery for the determination of the cytokines IL-6, IL-8 and TNF-alpha, and the adhesive molecule, sICAM-1, in newborns.

RESULTS

The sensitivity and specificity results are as follows, respectively: IL-6, 0.800 and 0.972; TNF-alpha, 0.364 and 0.943; IL-8, 0.875 and 0.965; and sICAM-1, 0.833 and 0.952.

CONCLUSIONS

For screening purposes, it is suitable to determine levels of IL-8, IL-6, and sICAM-1. For the screening examination, one of the cytokines mentioned is sufficient, i.e., IL-8 or IL-6, or the level of the adhesive molecule, sICAM-1. It is unnecessary to combine these markers.

Proteomics of the amniotic fluid in assessment of the placenta. Relevance for preterm birth

Proteomics is the study of expressed proteins and has emerged as a complement to genomic research. The major advantage of proteomics over DNA-RNA based technologies is that it more closely relates to phenotypes and not the source code. Proteomics thus holds the promise of providing a direct insight into the true mechanisms of human diseases. Historically, examination of the placenta has been the first modality to subclassify pathogenetic entities responsible for preterm birth. Because placenta is a key pathophysiological participant in several major obstetrical syndromes (preterm birth, pre-eclampsia, intrauterine growth restriction) identification of relevant biomarkers of placental function can profoundly impact on the prediction of fetal outcome and treatment efficacy. Since proteomics is a young science and studies that associate proteomic patterns with long-term outcome require follow-up of children up to school age, using placental pathological footprints of cellular injury as intermediate outcomes can be useful in the interim. Furthermore, knowledge on the identity of the dysregulated proteins may provide the needed breakthrough insight into novel pathophysiological pathways and unravel possible targets for therapeutical intervention that could not have been envisioned through hypothesis-driven approaches.

Prenatally fabricated autologous human living heart valves based on amniotic fluid derived progenitor cells as single cell source

BACKGROUND

A novel concept providing prenatally tissue engineered human autologous heart valves based on routinely obtained fetal amniotic fluid progenitors as single cell source is introduced.

METHODS AND RESULTS

Fetal human amniotic progenitors were isolated from routinely sampled amniotic fluid and sorted using CD133 magnetic beads. After expansion and differentiation, cell phenotypes of CD133- and CD133+ cells were analyzed by immunohistochemistry and flowcytometry. After characterization, CD133- derived cells were seeded onto heart valve leaflet scaffolds (n=18) fabricated from rapidly biodegradable polymers, conditioned in a pulse duplicator system, and subsequently coated with CD133+ derived cells. After in vitro maturation, opening and closing behavior of leaflets was investigated. Neo-tissues were analyzed by histology, immunohistochemistry, and scanning electron microscopy (SEM). Extracellular matrix (ECM) elements and cell numbers were quantified biochemically. Mechanical properties were assessed by tensile testing. CD133- derived cells demonstrated characteristics of mesenchymal progenitors expressing CD44 and CD105. Differentiated CD133+ cells showed features of functional endothelial cells by eNOS and CD141 expression. Engineered heart valve leaflets demonstrated endothelialized tissue formation with production of ECM elements (GAG 80%, HYP 5%, cell number 100% of native values). SEM showed intact endothelial surfaces. Opening and closing behavior was sufficient under half of systemic conditions.

CONCLUSIONS

The use of amniotic fluid as single cell source is a promising low-risk approach enabling the prenatal fabrication of heart valves ready to use at birth. These living replacements with the potential of growth, remodeling, and regeneration may realize the early repair of congenital malformations.

Intravenous maternal hydration in third trimester oligohydramnios: effect on amniotic fluid volume

OBJECTIVE

To determine the affect of acute intravenous maternal hydration on amniotic fluid volume in patients with third trimester oligohydramnios.

STUDY DESIGN

Quasi experimental study.

PLACE AND DURATION OF STUDY

Department of Obstetrics and Gynaecology Unit III, Sir Ganga Ram Hospital, Lahore, from May 2001 to April 2002.

PATIENTS AND METHODS

Twenty-five women with third trimester oligohydramnios (AFI < or = 5.0 cm) and 25 controls with normal amniotic fluid volume (AFI 8-24 cm) were prospectively recruited for this study. Study inclusion criteria were, singleton pregnancy, well-established gestational age, intact membranes, absence of maternal complication (anemia, cardiac disease, renal disease, pre-eclampsia, hypertension, or diabetes); absence of fetal structural malformation and/or distress. Maternal urinary specific gravity and amniotic fluid index were determined before and after intravenous hydration by infusing 2 liters of 5% dextrose water in 2 hours and recorded on printed proformas. Sample independent 't' test was used to compare the mean AFI and urine specific gravity before and after treatment, and the posttreatment AFI--pre-treatment AFI ( delta AFI).

RESULTS

Maternal hydration increased amniotic fluid volume (AFV) in women with oligohydramnios (mean change in amniotic fluid index 4.5 cm, 95% confidence interval 4.02 to 5.06; p-value<0.01); as well as in women with normal amniotic fluid volume (mean change in amniotic fluid index 2.7 cm, 95% confidence interval 2.23 to 3.21; p-value<0.01). The percentage increase in mean AFI was 58.6% in the oligohydramnios group, which was significantly greater (p<0.05) than the percentage increase of 28.4% in control group. Maternal hydration was associated with decrease in urinary specific gravity in both groups.

CONCLUSION

Under the conditions of this study, maternal (intravenous) hydration increased the AFV in women with oligohydramnios as well as in those with normal AFV and may be beneficial in the management of oligohydramnios.

A randomized clinical trial comparing the effect of maternal intravenous hydration and placebo on the amniotic fluid index in oligohydramnios

OBJECTIVE

To compare the treatment of acute intravenous hydration with placebo in term pregnant women manifesting oligohydramnios.

METHODS

All patients with oligohydramnios who met the inclusion criteria were offered participation in this randomized, double-blind, placebo-controlled study. After ruling out rupture of membranes and maternal and fetal complications, we recruited 44 women with third trimester singleton pregnancies having an amniotic fluid index (AFI) of less than 6. Patients were randomized into treatment or control groups. Patients in the treatment group received a continuous intravenous infusion of (1/2) normal saline (NS) at a rate of 1000 mL/h for two hours. Patients in the placebo group received an intravenous infusion of (1/2) NS at 10 mL/h for two hours. The AFI was re-assessed by the same sonographer one hour after the hydration was completed. Both the patient and the examiner were blinded to the study groups.

RESULTS

Maternal age, parity, gestational age, and birth weight were not significantly different between the two groups. The AFI increased significantly in both treatment (3.8 +/- 1.2 vs. 5.3 +/- 2.5, p < 0.05) and placebo (4 +/- 1.3 vs. 5.5 +/- 2.4, p < 0.05) groups. Moreover, the changes in AFI did not significantly differ between the treatment and the placebo groups (1.2 +/- 2.1 vs. 1.5 +/- 2.1, respectively; p > 0.05).

CONCLUSIONS

There are statistically significant short-term increases in the AFI in patients with oligohydramnios whether the patients are treated with intravenous fluids or not. The short-term increase in AFI may reflect physiologic diurnal variations in the amniotic fluid.

Fetal growth after preterm premature rupture of membranes: is it related to amniotic fluid volume?

OBJECTIVE

Preterm premature rupture of membranes (PPROM) has been associated with an increased rate of fetal growth restriction (FGR). It is unknown whether impairment of fetal growth is mediated through external compression from decreased amniotic fluid volume or (an)other mechanism(s).

METHODS

Over a three-year period all patients with singleton pregnancies experiencing PPROM at <37 weeks lasting greater than 10 days, and who underwent serial sonograms to assess fetal biometry after PPROM, were included in the study. Patients were excluded for congenital anomalies or other inherent risk factors for abnormal fetal growth. Fetal abdominal circumference (AC) percentiles were compared between the first sonographic exam after PPROM and the last exam before delivery. The median amniotic fluid index between PPROM and delivery was correlated with the change in AC percentiles while controlling for the duration of PPROM. Statistical analysis utilized one-way analysis of variance and correlation; a p value of <0.05 was considered significant.

RESULTS

Twenty-two patients met our inclusion criteria with a mean duration (+/-SD) of PPROM of 58 days (+/-46). The median AFI during the PPROM period was not correlated with the change in AC percentiles after controlling for duration of PPROM (p = 0.49).

CONCLUSIONS

The residual amniotic fluid volume after PPROM does not appear to correlate with fetal growth suggesting that the increased rate of FGR in PPROM is not secondary to oligohydramnios. We hypothesize that the intrauterine pathologic processes responsible for membrane rupture may also interfere with fetal growth.

Preexisting hypoxia is associated with a delayed but more sustained rise in T/QRS ratio during prolonged umbilical cord occlusion in near-term fetal sheep

There is limited information about whether preexisting fetal hypoxia alters hemodynamic responses and changes in T/QRS ratio and ST waveform shape during subsequent severe asphyxia. Chronically instrumented near-term sheep fetuses (124 +/- 1 days) were identified as either normoxic Pa(O(2)) > 17 mmHg (n = 9) or hypoxic Pa(O(2)) < or = 17 mmHg (n = 5); then they received complete occlusion of the umbilical cord for 15 min. Umbilical cord occlusion led to sustained bradycardia, severe acidosis, and transient hypertension followed by profound hypotension in both groups. Preexisting hypoxia did not affect changes in mean arterial blood pressure but was associated with a more rapid initial fall in femoral blood flow and vascular conductance and with transiently higher fetal heart rate at 2 min and from 9 to 11 min of occlusion compared with previously normoxic fetuses. Occlusion was associated with a significant but transient rise in T/QRS ratio; preexisting hypoxia was associated with a significant delay in this rise (maxima 3.7 +/- 0.4 vs. 6.2 +/- 0.5 min), but a slower rate of fall. There was a similar elevation in troponin-T levels 6 h after occlusion in the two groups [median (range) 0.43 (0.08, 1.32) vs. 0.55 (0.16, 2.32) microg/l, not significant]. In conclusion, mild preexisting hypoxia in normally grown singleton fetal sheep is associated with more rapid centralization of circulation after umbilical cord occlusion and delayed elevation of the ST waveform and slower fall, suggesting that chronic hypoxia alters myocardial dynamics during asphyxia.