RESUMEN
Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.
Asunto(s)
Corioamnionitis , Síndrome de Aspiración de Meconio , Complicaciones del Embarazo , Recién Nacido , Embarazo , Femenino , Humanos , Meconio , Líquido Amniótico/química , Inflamación/complicaciones , Hemo/análisisRESUMEN
AIM: To investigate the association between uterine bleeding preceding fetoscopic laser photocoagulation (FLP) and the presence of discolored amniotic fluid that impedes FLP. METHODS: A retrospective review of all multiple gestations requiring FLP at the present institution was conducted. The rate of low visibility because of discolored amniotic fluid at the beginning of FLP was compared between patients with and without a history of uterine bleeding, defined as either genital bleeding or ultrasonographically detected subchorionic hematoma. RESULTS: The prevalence of low visibility because of discolored amniotic fluid was 4.5% (seven in 156 patients). Two of the seven cases of low visibility resulted in double fetal death. The incidence of low visibility was significantly higher in the group with uterine bleeding before surgery compared with that without bleeding (28.6% vs 0.74%, P < 0.001). CONCLUSIONS: Patients with a history of uterine bleeding prior to FLP may encounter more technical difficulties owing to discolored amniotic fluid during FLP.
Asunto(s)
Líquido Amniótico , Fetoscopía/métodos , Coagulación con Láser/métodos , Complicaciones del Embarazo/cirugía , Hemorragia Uterina/complicaciones , Artefactos , Femenino , Muerte Fetal/etiología , Transfusión Feto-Fetal/cirugía , Edad Gestacional , Humanos , Embarazo , Embarazo Múltiple , Estudios RetrospectivosRESUMEN
OBJECTIVES: Amniocentesis is the most commonly used invasive method for prenatal diagnosis of genetic disorders. But this invasive study may induce preterm labor, endanger both the mother and the fetus, cause infection and abortion. This study was performed to clarify the safety and confidency of amniocentesis. MATERIAL AND METHODS: 1,500 amniocentesis cases were performed from 1987 to 1996 at Severance hospital for prenatal diagnosis of genetic disorders. Of 1,500 cases, 499 cases whose pregnancy outcomes were proven were finally analized. We compared incidence of complications such as spontaneous abortion, vaginal spotting, premature rupture of membranes, preterm labor or chorioamnionitis according to placental location, frequency of needle insertion and amniotic fluid color. RESULTS: 1) Indications for amniocentesis were (1) advanced maternal age - 47.3%, (2) positive maternal serum triple test - 13.8%, (3) fetal chromosomal anomaly suspected in ultrasonography - 10.0%. 2) 6.6% of the amniocentesis samples had color changes due to bleedng or meconium passing. 3) 18.8% of the cases were performed at 16th gestational weeks followed by 20th, 18th and 17th weeks. 4) 2.2% had complications such as spontaneous abortion, vaginal bleeding, premature rupture of membranes, preterm labor and chorioamnionitis in 4 weeks after amniocentesis. 5) No correlation was found between the placental location, frequency of needle insertion(below 3 times) and complication rate. The spontaneous abortion rate in the group with amniotic fluid discolorization was 6.1% whose only 0.4% had spontaneous abortion to the group with clear amniotic fluid. 6) Median value of amniotic fluid alphafetoprotein(alphaFP) of pregnant women in midtrimester were 15,769.4ng/ml at 15 weeks, 13,160.3ng/ml at 16 weeks, 11,539.3ng/ml at 17 weeks, 9,569.8 mg/ml at 18 weeks, 8,423.4mg/ml at 19 weeks, 6,527.1ng/ml at 20 weeks, 5,979.3ng/ml at 21 weeks, 4,363.2ng/ml at 22 weeks, 3,555.2ng/ml at 23weeks, respectively. In midtrimester amniotic fluid alphaFP declined gradually as gestational weeks increase. CONCLUSIONS: Fetal loss rate of midtrimester amniocentesis was 0.8%, proving that it outstanding in the aspects of safty and confidency. Since the fetal loss rate significantly increases in case with amniotic fluid discoloration, it is needless to mention the importance of close follow-up.