Prophylactic intrapartum amnioinfusion in patients with preterm premature rupture of membranes. A prospective, randomized evaluation of intrapartum amnioinfusion. Fetal acid-base status and cesarean delivery. Amnioinfusion for relief of recurrent severe and moderate variable decelerations in labor. Transcervical intrapartum amnioinfusion for preterm premature rupture of the membranes. Influence of volume preloading on uteroplacental and fetal circulation during spinal anaesthesia for caesarean section in uncomplicated singleton pregnancies. Prophylactic amnioinfusion for meconium-stained amniotic fluid. Therapeutic amnioinfusion for intrapartum fetal distress using a pediatric feeding tube. Amnioinfusion in term labor with low amniotic fluid due to rupture of membranes: a new indication. Prophylactic transcervical amnioinfusion in laboring women with oligohydramnios. Prophylactic intrapartum amnioinfusion for patients with oligohydramnios. A prospective randomized study. Intrapartum amnioinfusion in women with oligohydramniosis. A prospective randomized trial. Transabdominal amnioinfusion in oligohydramnios at term before induction of labor with intact membranes: a randomized clinical trial. Amnioinfusion during labor complicated by particulate meconium-stained amniotic fluid decreases neonatal morbidity. Prophylactic amnioinfusion improves outcome of pregnancy complicated by thick meconium and oligohydramnios. Saline amnioinfusion for relief of repetitive variable decelerations: a prospective randomized study.
Patients with preterm premature rupture of the membranes are at increased risk to develop intrapartum variable decelerations and fetal distress. Short-term saline solution amnioinfusion may be of benefit in the treatment of variable or prolonged decelerations once they appear. In an effort to assess the benefit of prophylactic amnioinfusion, patients with preterm premature rupture of the membranes were studied during a 1-year period in a prospective randomized manner. Patients receiving prophylactic amnioinfusion had significantly decreased incidence and severity of variable decelerations in the first stage of labor (p less than 0.005). In the second stage of labor, the incidence of severe (p less than 0.005) and total (p less than 0.001) decelerations was also decreased in the treatment group. The umbilical arterial pH at delivery was significantly lower (p less than 0.001) as was the umbilical venous pH (p less than 0.005) in the newborn infants of control patients compared with those of patients receiving amnioinfusion. This suggests that prophylactic intrapartum amnioinfusion is of significant benefit in reducing the incidence of variable decelerations and improving the metabolic state in newborn infants born to women with preterm premature rupture of the membranes. Pregnancies with decreased amniotic fluid volume are prediposed to umbilical cord compression and variable fetal heart rate declerations. Intrapartum amnioinfusion has been utilized in an effort to reduce cord compression. Previous studies suggested that amnioinfusion may improve the fetal metabolic state and reduce the incidence of cesarean delivery in selected patients. In this study the hypothesis was tested that intrapartum amnioinfusion will relieve cord compression in pregnancies complicated by oligohydramnios and will result in a reduced incidence of fetal intolerance to labor as well as improved fetal acid-base status at delivery. Thirty-five patients fulfilling the inclusion criteria were randomized to either the control (n = 16) or amnioinfusion treatment group (n = 19). Analysis of the data suggested that the two groups were similar for the perinatal parameters evaluated. No differences were observed in the umbilical artery blood gas analysis or incidence of cesarean section between the two groups. Intrapartum amnioinfusion does not appear to improve the perinatal outcome in pregnancies with oligohydramnios. To determine whether intrapartum amnioinfusion (AI) relieves recurrent moderate and severe variable decelerations in laboring women with clear or grade I meconium-stained amniotic fluid and reduces cesarean section rate for fetal distress.
                A randomized controlled trial was conducted in labor unit of Christian Medical College Hospital, Vellore, India, between October 2003 and September 2004. Women were randomized to receive AI (group I) and not to receive it (group II).
                A total of 150 women (75 in each group) were included in the study. There was significant relief of variable decelerations in group I and no difference in overall cesarean section rate but significant reduction in cesarean section rate for fetal distress in group I, and significant reduction in cesarean section rate for fetal distress in nulliparous women of group I. Neonatal acidemia was also significantly reduced in the nulliparous women receiving AI. The duration of maternal postpartum hospital stay was significantly reduced in group I. There were no adverse maternal or neonatal outcomes.
                AI was a beneficial therapeutic intervention in women patients showing fetal distress in first stage of labor, and it reduced cesarean section for fetal distress and neonatal acidemia. To investigate the effect of transcervical amnioinfusion on the management of labour and neonatal outcomes in preterm premature rupture of the membranes.
                This clinical trial included 86 patients with premature rupture of the membranes between weeks 27 and 35 of gestation. Patients were randomly assigned to receive amnioinfusion via a two-way catheter or to the control group. Clinical management was otherwise the same in both groups.
                Amnioinfusion decreased the frequency of variable decelerations in fetal heart rate (27.9% versus 53.5%, p<0.05) and the rate of obstetric interventions motivated by nonreassuring fetal status (13.6% versus 52.4%, p<0.05). At delivery, pH values were significantly higher in the treatment group than in the conventionally managed control group (median 7.29 versus 7.27).
                Intrapartum transcervical amnioinfusion for preterm premature rupture of the membranes reduced the number of interventions needed because of nonreassuring fetal status, and improved neonatal gasometric values without increasing maternal or fetal morbidity. Effects of volume preloading during spinal anaesthesia for elective caesarean section on maternal blood pressure, feto-maternal circulation and fetal outcome.
                In a pilot study a randomised trial was performed in 22 healthy women with uncomplicated, singleton pregnancies at 36-40 weeks of gestation undergoing elective caesarean section under spinal anaesthesia. In the low volume group (group A) patients received 150 ml of crystalloid solution for preloading, in the high volume group (group B) they were given 15 ml/kg of crystalloid solution for preloading before the initiation of spinal anaesthesia. Maternal blood pressure was monitored intermittently. Hypotension was defined as a decrease in systolic pressure to less than 80% of the baseline value. The Doppler flow evaluation consisted of measurements from the uterine artery at the placental site, fetal umbilical artery and fetal middle cerebral artery. Pulsatility indices were derived before and after fluid preloading, and when spinal anaesthesia was established. The neonatal outcome was assessed by Apgar scores, arterial acid base status and neurologic and adaptive capacity scores (NACS).
                The incidence of maternal hypotension in both groups was 45.5% (n = 10); 3 cases occurred in group A compared to 7 cases in group B (n.s.). There was no evidence that the high dose volume is useful in preventing maternal hypotension. The pulsatility indices of uterine arteries, umbilical arteries and middle cerebral arteries were not altered. Statistical analysis showed no changes in neonatal outcome concerning umbilical arterial pH, Apgar score and NACS (n.s.) between groups A and B.
                Our preliminary results suggest that high dose crystalloid volume preloading has no preventive function in the avoidance of maternal hypotension in healthy parturients undergoing elective caesarean section under spinal anaesthesia, and shows no harmful effects on neonatal outcome as long as maternal hypotension is corrected immediately. However, the statistical significance may reflect the small sample size, and larger series are needed before changing the current management.
                Copyright 2002 S. Karger AG, Basel Previous studies have demonstrated reduced perinatal morbidity in patients receiving amnioinfusion for meconium-stained amniotic fluid compared with control patients receiving no amnioinfusion. Because amnioinfusion for variable fetal heart rate decelerations has become accepted care, we sought to determine the benefit of prophylactic amnioinfusion for meconium compared with standard care, incorporating therapeutic amnioinfusion for variable decelerations.
                Ninety-three term patients with moderate to heavy meconium and no variable fetal heart rate decelerations were randomized to immediate prophylactic amnioinfusion (600 ml saline solution bolus followed by 3 ml/min) or to standard care (including therapeutic amnioinfusion for variable decelerations developing later). All babies had DeLee suctioning on delivery of the head. Laryngeal cords were visualized and tracheal suctioning performed when meconium was seen below the cords. Statistical comparisons were performed using Student t test, Fisher's exact test, or chi 2 analysis.
                There were no significant differences in the incidence of operative delivery, fetal distress, or meconium below the cords or in newborn Apgar scores and umbilical artery gas values between the amnioinfusion (n = 43) and control (n = 50) patients. There were four cases of meconium aspiration, three in the amnioinfusion group, one in the standard care group. The rate of endometritis-chorioamnionitis was higher (p = 0.3) in the amnioinfusion (16%) than in the control group (8%), although time from ruptured membranes to delivery (8.5 hours vs 7.3 hours) and duration of intrauterine monitoring (6.1 hours vs 5.3 hours) were not different.
                Although amnioinfusion does dilute amniotic meconium, prophylactic amnioinfusion for meconium in the absence of variable decelerations remains controversial. Prophylactic amnioinfusion in term pregnancies did not improve perinatal outcome and increased the risk for chorioamnionitis-endometritis. Together with recent reports, the current data suggest that the benefit of amnioinfusion for meconium-stained amniotic fluid is a result of the alleviation of variable fetal heart rate decelerations rather than meconium dilution. To evaluate the role of therapeutic amnioinfusion using a pediatric feeding tube in cases of intrapartum fetal distress.
                A randomized clinical trial including 438 women admitted in labor at Assiut University Hospital with nonreassuring fetal heart rate tracing. Using sealed opaque envelopes, the women were randomized to 2 groups. In the amnioinfusion group they underwent transcervical amnioinfusion (1000 mL of warmed sterile saline solution) in addition to conventional treatment. In the control group they received conventional treatment only. The primary outcome was cesarean section rate for fetal distress. The secondary outcomes were neonatal and maternal complications.
                The amnioinfusion group showed a significant reduction in the rate of cesarean section for fetal distress (relative risk [RR], 0.7; 95% confidence interval [CI], 0.6-0.83), and a 30% reduction in abnormal fetal heart rate patterns (RR, 0.7; 95% CI, 0.6-0.83). Significantly fewer newborns had Apgar scores less than 7 at 1 and 5 min in the amnioinfusion group than in the control group (RR, 0.38; 95% CI, 0.26-0.55 and RR, 0.31; 95% CI, 0.15-0.64, respectively). Significantly fewer newborns had meconium below the vocal cords in the amnioinfusion group than in the control group (RR, 0.36; 95% CI, 0.13-0.97). Moreover, 14 newborns in the amnioinfusion group needed admission to the intensive care unit vs. 31 newborns in the control group. There were no significant differences between the 2 groups regarding the incidence rates of uterine hypertonus and maternal temperature higher than 38 degrees C.
                Therapeutic amnioinfusion is a simple and effective intervention that reduces the rates of cesarean section for intrapartum nonreassuring fetal heart tracing. In under-resourced settings, it can be performed using inexpensive catheters. The null hypothesis was that the use of intrapartum amnioinfusion to induce term labor because of premature rupture of membranes when labor was complicated by low amniotic fluid volume due to vaginal loss would not improve fetal heart rate patterns, decrease the incidence of operative delivery, or improve neonatal acid-base status.
                200 term pregnancies with low amniotic fluid due to vaginal loss were randomly chosen to receive intrapartum amnioinfusion or standard obstetric care without amnioinfusion. Fetal heart rate pattern, method of delivery and neonatal acid-base status were compared with Student's t test, chi-squared analysis, Mann-Whitney U- or Fisher's exact test.
                When amnioinfusion was used, the fetuses had lower rates of variable (74 vs. 91%, P<0.01) or late (26 vs. 58%, P<0.001) decelerations. Spontaneous deliveries were more frequent (77 vs. 59%, P<0.01) and cesarean sections less frequent (3 vs. 10%, P<0.05). Mean umbilical arterial (7.24+/-0.07 vs. 7.21+/-0.08, P<0.01) and venous (7.31+/-0.06 vs. 7.28+/-0.08, P<0.01) pH were significantly higher in newborns with amnioinfusion, and babies in this group had lower rates of neonatal acidemia of arterial (22 vs. 36%, P<0.005) or venous (13 vs. 26%, P<0.005) origin.
                Amnioinfusion improved fetal heart rate pattern, lowered the incidence of operative delivery, and improved neonatal acid-base status in term labor complicated by low amniotic fluid due to vaginal loss. Evaluation of prophylactic intrapartum amnioinfusion in women with oligohydramnios.
                Assiut University Hospital during the period from February 2000 to September 2001, 160 laboring women with oligohydramnios [amniotic fluid index (AFI) </=5 cm] were randomized into: amnioinfusion and control groups. Inclusion criteria were: term singleton gestation, vertex presentation, cervical dilatation <4 cm, and assuring fetal heart rate (FHR). Trans-cervical amnioinfusion was done with warmed normal saline.
                there was a significant increase in AFI after amnioinfusion (P<0.001). The amnioinfusion group showed lower cesarean section rate for fetal distress (P=0.003), lower incidence of abnormal FHR (P=0.006), fewer neonates with Apgar score <7 at 1 min (P<0.001), and 5 min (P=0.009), meconium below vocal cords (P<0.001), umbilical arterial pH<7.1 (P=0.003), and significantly shorter hospital stay (P=0.02).
                Prophylactic trans-cervical amnioinfusion is a simple, safe and effective procedure. This prospective study evaluated whether prophylactic saline amnioinfusion among patients with amniotic fluid index (AFI) < or = 5.0 cm decreases the incidence of adverse fetal outcomes. Randomization of 53 patients with decreased AFI at term, resulted in 21 patients' receiving prophylactic saline amnioinfusion early in labor, prior to development of an abnormal fetal heart rate tracing. For the treatment group the mean AFI on admission was 3.0 cm, and the postamnioinfusion AFI was 8.9 cm. For 32 comparison (noninfusion) patients, the mean AFI was 2.9 cm; the group consisted of 17 patients randomized to receive no amnioinfusion (control group) and 15 patients who refused to participate in the study. There was no statistically significant difference between the amnioinfused and nonamnioinfused patients with regard to age, parity, gestational age, AFI at admission or duration of first or second stage of labor. Amnioinfusion resulted in no statistically significant reduction in the incidence of recurrent variable decelerations/bradycardia (26.3% vs. 46.6%), intrapartum resuscitation with terbutaline (5.2% vs. 10.0%), cesarean section for fetal distress (9.5% vs. 9.3%), fetal-acidosis (10.5% vs. 12.0%) or Apgar scores < 7 at five minutes (5.2% vs. 0%) in patients with oligohydramnios. To evaluate the effects of amnioinfusion in oligohydramniosis.
                During a 20-month period, patients at term with oligohydramniosis (amniotic fluid index less than 5 cm) at Huddinge University and Norrköping Hospitals were recruited for a prospective randomized study to evaluate amnioinfusion. Informed consent was obtained from 112 patients who met the entry criteria. Sixty subjects were randomized to amnioinfusion and 52 to the control group. Outcome parameters included fetal heart rate abnormalities, mode of delivery, Apgar score, pH in umbilical artery blood and need for neonatal intensive care.
                The cesarean section rate was significantly reduced in the amnio-infusion group (29% versus 13%, p=0.043). No difference in time from randomization to delivery was detected between the two groups. The frequency of ominous fetal heart rate tracings with a cervical dilatation of 0-3 cm was the same in the two groups. The frequency of such heart rate patterns after amnioinfusion was significantly lower than in the control group. Neonatal outcome, pH in the umbilical artery blood and need for neonatal intensive care did not differ between the two groups.
                The present study confirms the findings of other authors that amnioinfusion effectively reduces the number of cesarean sections in cases of oligohydramniosis. Our purpose was to determine the effectiveness of transabdominal amnioinfusion before induction of labor in reducing the incidence of fetal distress in pregnancies with oligohydramnios at term.
                Between June 1991 and September 1994 primiparous women with ultrasonographic evidence of oligohydramnios at term, intact membranes, and unripe cervix (Bishop score < or = 6), candidates for induction of labor with cervical or vaginal prostaglandin E2 gel, were randomly selected to receive transabdominal amnioinfusion (amnioinfused group, n = 39) or to proceed with direct labor induction (control group, n = 40). Inclusion criteria were (1) singleton gestation, (2) vertex presentation, (3) ultrasonographic estimation of fetal weight > or = 2500 gm, and (4) reactive nonstress test. Fetoneonatal outcome variables were compared between the two groups. Statistical analysis used contingency tables, Student t test, or Wilcoxon rank-sum tests, where applicable.
                Amnioinfusion was successfully performed in 100% of the patients randomized for the procedure. The incidence of severely abnormal fetal heart rate tracings was significantly higher in the control than in the amnioinfused group (42% [17/33] vs 5% [2/37], relative risk 12.9, 95% confidence interval 2.4 to 56.4). The rate of cesarean sections performed for fetal distress was fivefold higher in the control group (25% [10/40] vs 5% [2/39], relative risk 4.9, 95% confidence interval 1.1 to 32.4). No bleeding complications or fetomaternal infectious morbidity were noticed.
                Transabdominal amnioinfusion is a safe, effective option for the prevention of fetal distress in pregnancies with oligohydramnios at term with intact membranes and unripe cervix. Our purpose was to evaluate the efficacy of prophylactic amnioinfusion in decreasing neonatal morbidity associated with labor complicated by particulate meconium-stained amniotic fluid and to assess potential complications of this procedure.
                One hundred five laboring pregnant women with particulate (moderate or thick) meconium by subjective clinical analysis were randomly assigned to receive amnioinfusion or to receive standard obstetric care without amnioinfusion. Patients with any antepartum complications, other than the presence of meconium, were excluded from the study. Statistical analyses consisted of the two-tailed and paired Student t tests, Pearson chi 2 test, and Wilcoxon nonparametric test. Significance was set at p < 0.05.
                The study included 47 patients in the study group and 58 patients in the control group. A significantly greater proportion of study patients demonstrated decreased meconium concentration between rupture of membranes and delivery (46 of 46 vs 15 of 58, p < 0.001). The relative dilution of meconium consistency by objective analysis was significantly different between the study group and the control group (77.1% decrease vs 9.3% increase, p < 0.001). The proportion of neonates with meconium below the vocal cords was reduced in the study group (two of 47 vs 36 of 58, p < 0.001). Umbilical artery pH was increased in the study group neonates (7.29 +/- 0.01 vs 7.25 +/- 0.009, p < 0.05). The rate of neonatal acidemia was reduced in the study group (4 of 45 vs 12 of 50, p < 0.05). The rate of meconium aspiration syndrome was reduced in the study group (1 of 47 vs 8 of 58, p < 0.05). Maternal and neonatal morbidity rates were similar.
                Prophylactic amnioinfusion should be considered a possible addition to the intrapartum management of patients with particulate meconium-stained amniotic fluid. The null hypothesis is that the use of intrapartum amnioinfusion in labors complicated by the presence of thick meconium and oligohydramnios will not decrease the incidence of fetal distress, cesarean delivery, meconium aspiration, or meconium aspiration syndrome.
                One hundred seventy term and postterm patients with thick meconium and oligohydramnios were randomly chosen to receive amnioinfusion or standard obstetric care without amnioinfusion. The frequency of fetal distress, cesarean section, meconium aspiration, and meconium aspiration syndrome were subject to chi 2 analysis, Student's t test, or Fisher's exact test.
                The rate of fetal distress was significantly reduced in the amnioinfusion group compared with controls (three of 85 vs 19 of 85, relative risk 0.15, 95% confidence interval 0.06 to 0.42). The rate of cesarean section for fetal distress was significantly reduced in the amnioinfusion group (two of 85 vs 17 of 85, relative risk 0.118, confidence interval 0.03 to 0.49). The rates of meconium aspiration (four of 85 vs 33 of 85, relative risk 0.12, confidence interval 0.0449 to 0.327) and meconium aspiration syndrome (0 of 85 vs five of 85, relative risk 0.09, confidence interval 0.009 to 0.872) were significantly reduced by amnioinfusion.
                Amnioinfusion improves the outcome in pregnancies complicated by thick meconium and oligohydramnios. A prospective randomized study was undertaken in order to further investigate the effect of intrauterine saline amnioinfusion for the relief of repetitive variable decelerations in the first stage of labor. Intrauterine saline amnioinfusion corrects the oligohydramnios that makes the cord more vulnerable to compression during uterine contractions. Included in this study were 96 patients who had repetitive variable decelerations not relieved either by changes in position or by oxygen. Randomization resulted in 49 patients in the infusion group and 47 patients in the noninfusion group. Relief of variable decelerations was 51% in the infusion group, as compared to 4.2% in the noninfusion group. Relief of variable decelerations was more dramatic in the nulliparous infusion group (66.7%) than in the noninfusion group (0%). In the nulliparous patients there was a significant decrease in the rate of cesarean sections for fetal distress, being 14.8% in the infusion group as compared to 47.6% in the noninfusion group. This study clearly showed that saline amnioinfusion is a logical, simple, safe, and effective therapy for the relief of repetitive variable decelerations in the first stage of labor and can lower the incidence of cesarean sections for fetal distress in nulliparous patients. Furthermore, amnioinfusion was much superior to changes in position in treating repetitive variable decelerations.
The use of amnioinfusion for potential or suspected umbilical cord compression may be of considerable benefit to mother and baby by reducing the occurrence of variable FHR decelerations, improving short-term measures of neonatal outcome, reducing maternal postpartum endometritis and lowering the use of caesarean section, although there were methodological limitations to the trials reviewed here. In addition, the trials are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion. More research is needed to confirm the findings, assess longer-term measures of fetal outcome, and to assess the impact on caesarean section rates when the diagnosis of fetal distress is more stringent. Trials should assess amnioinfusion in specific clinical situations, such as FHR decelerations, oligohydramnios or prelabour rupture of membranes.