Amniocentesis Archives - Revista Brasileira de Ginecologia e Obstetrícia
Summary
Rev Bras Ginecol Obstet. 1998;20(6):315-321
DOI 10.1590/S0100-72031998000600004
The objective was to evaluate the accuracy of the foam stability test, lecithin/sphingomyelin (LS) ratio, presence of phosphatidylglycerol (PG) and lung profile (L/S ratio > 1.7 and PG present simultaneously) in 121 consecutive high-risk gestations at the São Paulo Hospital from January 1990 to January 1995. Delivery occurred within 3 days of fetal lung maturation testing. This is a prospective study in which the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of all the tests were determined. Neonatal respiratory outcome and amniocentesis results were stratified by gestational age for comparison. The distribution of the studied population according to maternal pathology was diabetes mellitus (48), hypertensive disorders (41), Rh isoimmunization (14) and miscellaneous (18). Respiratory distress (RD) was present in 33 infants (27.2%), mainly in the diabetic group. There was no false negative using lung profile (all patients) and foam stability tests among hypertensive pregnancies (specificity 100%), but there were about 20% to 50% false positives in the other tests. Overall, all four tests had a low PPV: 23% for foam test, 51% for L/S ratio, 63% for PG, 61% for lung profile, and high NPV: 92% for foam test, 88% for L/S ratio, 89% for PG and 100% for lung profile. All tests had less accuracy in the diabetic pregnant women. This study shows that the presence of PG and L/S ratio > 1.7 in the amniotic fluid of high-risk pregnancies confirms maturity with a very low risk to develop RD and that the foam stability test was useful as a first-line test to predict the absence of surfactant-deficient respiratory distress syndrome, particularly in hypertensive pregnant women.
Summary
Rev Bras Ginecol Obstet. 1998;20(6):315-321
DOI 10.1590/S0100-72031998000600004
The objective was to evaluate the accuracy of the foam stability test, lecithin/sphingomyelin (LS) ratio, presence of phosphatidylglycerol (PG) and lung profile (L/S ratio > 1.7 and PG present simultaneously) in 121 consecutive high-risk gestations at the São Paulo Hospital from January 1990 to January 1995. Delivery occurred within 3 days of fetal lung maturation testing. This is a prospective study in which the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of all the tests were determined. Neonatal respiratory outcome and amniocentesis results were stratified by gestational age for comparison. The distribution of the studied population according to maternal pathology was diabetes mellitus (48), hypertensive disorders (41), Rh isoimmunization (14) and miscellaneous (18). Respiratory distress (RD) was present in 33 infants (27.2%), mainly in the diabetic group. There was no false negative using lung profile (all patients) and foam stability tests among hypertensive pregnancies (specificity 100%), but there were about 20% to 50% false positives in the other tests. Overall, all four tests had a low PPV: 23% for foam test, 51% for L/S ratio, 63% for PG, 61% for lung profile, and high NPV: 92% for foam test, 88% for L/S ratio, 89% for PG and 100% for lung profile. All tests had less accuracy in the diabetic pregnant women. This study shows that the presence of PG and L/S ratio > 1.7 in the amniotic fluid of high-risk pregnancies confirms maturity with a very low risk to develop RD and that the foam stability test was useful as a first-line test to predict the absence of surfactant-deficient respiratory distress syndrome, particularly in hypertensive pregnant women.
Summary
Rev Bras Ginecol Obstet. 1998;20(9):525-531
DOI 10.1590/S0100-72031998000900006
Purpose: to calculate sensitivity, specificity and positive and negative predictive values for multiparameter ultrasound scores for Down's syndrome. Patients and Methods: sensitivity and specificity for Down syndrome were calculated for ultrasound scores in a prospective study of ultrasound signs from 16 to 24 weeks in a high-risk population who denied invasive procedures after genetic counselling. The signs and scores were: femur/foot length < 0,9 (1), nuchal fold > 5 mm (2), pyelocaliceal diameter > 5 mm (1), nasal bones < 6 mm (1), absent or hypoplastic fifth median phalanx (1) and major structural malformations (2). Complete follow-up was obtained in each case. Genetic amniocentesis was proposed in the case of score 2 or more. Results: a total of 963 patients were examined from October 93 to December 97 at a mean gestational age of 19.6 (range 16 -24) weeks. Women's age ranged from 35 to 47 years (mean 38.8) and 18 Down syndrome cases were observed (1.8%). Sensitivity was 94.5% (17/18) for score 1 and 73% (13/18) for score 2 (false positive rate of 9.8% for score 1 and 4.1% for score 2). Individual sign sensitivity and specificity were: femur/foot = 16.7% (3/18) and 96.8% (915/945); nasal bones = 22.2% (4/18) and 92.1% (870/945); nuchal fold = 44.4% (8/18) and 96.5% (912/945); pyelic diameter = 38.9% (7/18) and 94.3% (891/945); absent phalanx = 22.2% (4/18) and 98.5% (912/945); malformation = 22.2% (4/18) and 98.2% (928/945). Conclusions: the overall sensitivity for score 1 was high but false positive rates were also high. For score 2, sensibility was still good (73%) and false positive rate was acceptable (4.1%). Positive and negative predictive values can be calculated for each prevalence (women's age). More cases are needed to reach final conclusions about this screening method (specially in a low-risk population) although this system has been useful for high-risk patients who deny invasive procedures.
Summary
Rev Bras Ginecol Obstet. 1998;20(9):525-531
DOI 10.1590/S0100-72031998000900006
Purpose: to calculate sensitivity, specificity and positive and negative predictive values for multiparameter ultrasound scores for Down's syndrome. Patients and Methods: sensitivity and specificity for Down syndrome were calculated for ultrasound scores in a prospective study of ultrasound signs from 16 to 24 weeks in a high-risk population who denied invasive procedures after genetic counselling. The signs and scores were: femur/foot length < 0,9 (1), nuchal fold > 5 mm (2), pyelocaliceal diameter > 5 mm (1), nasal bones < 6 mm (1), absent or hypoplastic fifth median phalanx (1) and major structural malformations (2). Complete follow-up was obtained in each case. Genetic amniocentesis was proposed in the case of score 2 or more. Results: a total of 963 patients were examined from October 93 to December 97 at a mean gestational age of 19.6 (range 16 -24) weeks. Women's age ranged from 35 to 47 years (mean 38.8) and 18 Down syndrome cases were observed (1.8%). Sensitivity was 94.5% (17/18) for score 1 and 73% (13/18) for score 2 (false positive rate of 9.8% for score 1 and 4.1% for score 2). Individual sign sensitivity and specificity were: femur/foot = 16.7% (3/18) and 96.8% (915/945); nasal bones = 22.2% (4/18) and 92.1% (870/945); nuchal fold = 44.4% (8/18) and 96.5% (912/945); pyelic diameter = 38.9% (7/18) and 94.3% (891/945); absent phalanx = 22.2% (4/18) and 98.5% (912/945); malformation = 22.2% (4/18) and 98.2% (928/945). Conclusions: the overall sensitivity for score 1 was high but false positive rates were also high. For score 2, sensibility was still good (73%) and false positive rate was acceptable (4.1%). Positive and negative predictive values can be calculated for each prevalence (women's age). More cases are needed to reach final conclusions about this screening method (specially in a low-risk population) although this system has been useful for high-risk patients who deny invasive procedures.
Summary
Rev Bras Ginecol Obstet. 1999;21(3):171-174
DOI 10.1590/S0100-72031999000300009
In pregnant women with cervical incompetence in whom there is also dilatation of the cervix and prolapsed membranes there are technical difficulties in performing cerclage in order to prolongate pregnancy until sufficient fetal maturity assures survival of the newborn. We describe a case of cervical incompetence with prolapsed membranes at 21 weeks of gestation, in which we caused the decrease of intrauterine pressure with drainage of amniotic fluid by amniocentesis, until reintroduction of membranes into the uterine cavity was possible. This procedure allowed traction of cervical lips and cerclage with less mechanical trauma, warranting the evolution of pregnancy for 12 weeks and fetal survival
Summary
Rev Bras Ginecol Obstet. 1999;21(3):171-174
DOI 10.1590/S0100-72031999000300009
In pregnant women with cervical incompetence in whom there is also dilatation of the cervix and prolapsed membranes there are technical difficulties in performing cerclage in order to prolongate pregnancy until sufficient fetal maturity assures survival of the newborn. We describe a case of cervical incompetence with prolapsed membranes at 21 weeks of gestation, in which we caused the decrease of intrauterine pressure with drainage of amniotic fluid by amniocentesis, until reintroduction of membranes into the uterine cavity was possible. This procedure allowed traction of cervical lips and cerclage with less mechanical trauma, warranting the evolution of pregnancy for 12 weeks and fetal survival
Summary
Rev Bras Ginecol Obstet. 2004;26(3):241-245
DOI 10.1590/S0100-72032004000300011
The reduction of mother-to-child transmission (MTCT) of the HIV-1 using zidovudine (ZDV) represents a cornerstone in the prenatal and obstetrical care to these patients. The invasive fetal and obstetric procedures are proscribed in HIV-1 infected pregnant patients, to avoid the increased risk of MTCT of this virus. The authors present a case of an HIV-1 infected woman with recurrent polyhydramnios. Four ultrasound-guided amniotic punctures were performed in the 23rd, 26th, 27th and 29th weeks of gestation, each one draining the respective volumes of 1,800, 1,450, 1,700 and 1,960 ml of clear amniotic fluid. The patient started preterm labor with 30 weeks and 5 days resulting in vaginal delivery of a male neonate weighing 1,690g and measuring 43cm. The baby presented a post natal diagnosis of a sodium-losing nephropathy and was submitted to three negative polymerase chain reaction tests for HIV-1. The authors point out that the option to manage cases of HIV-1 infected pregnancies that could need invasive obstetric procedures should be to give the patient 2 mg//kg of ZDV endovenously before the procedure, in order to avoid MTCT of HIV-1, as it has demonstrated good results in this case.
Summary
Rev Bras Ginecol Obstet. 2004;26(3):241-245
DOI 10.1590/S0100-72032004000300011
The reduction of mother-to-child transmission (MTCT) of the HIV-1 using zidovudine (ZDV) represents a cornerstone in the prenatal and obstetrical care to these patients. The invasive fetal and obstetric procedures are proscribed in HIV-1 infected pregnant patients, to avoid the increased risk of MTCT of this virus. The authors present a case of an HIV-1 infected woman with recurrent polyhydramnios. Four ultrasound-guided amniotic punctures were performed in the 23rd, 26th, 27th and 29th weeks of gestation, each one draining the respective volumes of 1,800, 1,450, 1,700 and 1,960 ml of clear amniotic fluid. The patient started preterm labor with 30 weeks and 5 days resulting in vaginal delivery of a male neonate weighing 1,690g and measuring 43cm. The baby presented a post natal diagnosis of a sodium-losing nephropathy and was submitted to three negative polymerase chain reaction tests for HIV-1. The authors point out that the option to manage cases of HIV-1 infected pregnancies that could need invasive obstetric procedures should be to give the patient 2 mg//kg of ZDV endovenously before the procedure, in order to avoid MTCT of HIV-1, as it has demonstrated good results in this case.