Biomedical subjects
Publications and source records attributed to W H Sepúlveda.
Cervical pregnancy is one of the most dangerous forms of ectopic pregnancy. This condition is frequently unsuspected before evaluation of the uterus and it is characterized by massive bleeding during that procedure. We report a case of cervical ectopic pregnancy diagnosed by ultrasound at 11 weeks' gestation and managed by emergency hysterectomy for severe hemorrhage occurring immediately after removal of the placenta.
Although hepatic hemangioma represents the most common tumor of the liver during childhood, the prenatal diagnosis of this condition has been rarely reported in the literature. In this report, we describe a case of hepatic hemangioma presenting as a small hyperechogenic mass (1.1 x 0.9 cm) in the fetal liver in which the diagnosis was made at 33 weeks' gestation by ultrasound. Subsequent postnatal evaluation by Doppler ultrasound confirmed the diagnosis and follow-up examinations have documented its spontaneous regression. The prenatal diagnosis of a liver mass allows not only the evaluation of changes in size or pattern of the mass itself during pregnancy but also its prompt evaluation after birth.
Acardiac twinning is a rare complication of monozygotic twin gestation occurring in 1/35,000 pregnancies or in 1% of all monozygotic twins. This condition is characterized by partial or complete lack of development of the heart in one of the twins, and requires that the normal twin (pump twin) provides circulation for itself as well as the acardiac sibling (perfused twin) by means of reverse circulation through large artery-to-artery and vein-to-vein anastomoses. The acardiac anomaly is uniformly fatal for the perfused twin, and the perinatal mortality for the normal twin is about 50%, usually as the result of congestive heart failure, polyhydramnios, and preterm delivery. In this report we present two cases of acardiac twin prenatally diagnosed by ultrasound. The principal sonographic features for prenatal diagnosis and the clinical management are briefly discussed.
Perforation of the urinary bladder by an intrauterine device (IUD) is extremely rare. In this report we present a case of ultrasound diagnosis of perforation of the bladder by a Copper-T IUD.
Fetal cystic hygroma colli (FCHC) is a congenital malformation of the lymphatic system which develops as a result of failure of the communication between the jugular lymphatic canal and the internal jugular vein. The diagnosis is usually made by ultrasound in the second trimester of pregnancy by the demonstration of a multiseptate, thin-walled cystic mass appearing posterolaterally in position to the fetal head and neck region. In this report we present two cases of FCHC diagnosed by transabdominal ultrasound in the first trimester of pregnancy. In one case, chorionic villus sampling revealed a 45,X karyotype, the fetus became progressively hydropic and died at 15 1/2 weeks. In the other, the spontaneous resolution of a nonseptated FCHC in a fetus with normal karyotype was documented, resulting in the delivery of a healthy infant a term. Fetal karyotyping, a careful search for other anomalies that may affect fetal survival, and a close sonographic follow-up in cases of FCHC are advocated for an accurate diagnosis and genetic counselling.
A new test for the evaluation of fetal lung maturity, called tap test, been recently developed. This rapid, inexpensive, and reliable test is easy to perform and can be used whenever testing for phospholipids are not available. We performed this test in 260 clear samples of amniotic fluid obtained by transabdominal amniocentesis and the results were compared with those of the "shake test". When the "shake test" was positive (n = 156), the tap test was consistent with fetal lung maturity in all cases. When the "shake test" was intermediate or negative (n = 61 and n = 43, respectively), the tap test was consistent with immaturity in only 19.2% of the cases. Fifty-four fetuses were born within 72 hours after the amniocentesis. The "shake test" was positive in 50, intermediate in 3, and negative in 1. In all but one of there cases the tap test was consistent with maturity. The only case of RDS in this series occurred in an infant with immature result. These findings indicate that the tap test is a reliable indicator of fetal pulmonary maturity and probably with a higher specificity than the "shake test".
Bilateral renal agenesis (BRA) is an uniformly lethal malformation occurring in 0.1-0.3/1000 births. This condition is associated with severe oligohydramnios, intrauterine growth retardation (IUGR), extra-renal anomalies, and malpresentation. The aim of this study was to present our experience with 10 cases of BRA seen in a 10-year period. In only one case the prenatal diagnosis was made. Therefore, the clinician was faced with a high-risk pregnancy: 70% of cases presented with malpresentation, oligohydramnios, and severe IUGR. This explain the high rate of cesarean section (40%) and the neonatal intensive care offered to these neonates. The principal methods to improve the prenatal diagnosis of this condition are discussed.
Intrahepatic cholestasis of pregnancy (ICP) is a rare complication of late pregnancy associated with a high rate of premature delivery, antepartum fetal death and fetal hypoxia. Since the principal biochemical feature of ICP is a marked elevation of maternal serum bile acid levels, a role of these substances in the pathophysiology of fetal complications has been suggested. In this study, the effect of bile acids on isolated human placental chorionic veins is described. High concentrations of bile acids, especially cholic acid, have a dose-dependent vasoconstrictive effect, which suggests that these substances could exert a detrimental effect on the fetus by increasing the resistance in chorionic veins through a vasospasm of the placental chorionic surface. An abrupt reduction of the oxygenated blood flow at the level of the placental chorionic plate may cause an acute impairment of the fetal perfusion and oxygenation, leading to fetal asphyxia. This is the first report that provides experimental evidence of the possible role of bile acids in those mechanisms that trigger fetal asphyxia in pregnancies complicated by ICP.
The vasomotor effects of histamine and its interaction with serotonin were studied in isolated human placental chorionic veins. Histamine induced concentration-dependent contractions with an EC50 of 8.7 +/- 1.2 x 10(-6) mol/l. The H1 antagonist, pyrilamine (10(-9) to 10(-7) mol/l), inhibited histamine-induced contractions, with a pA2 of 8.33 +/- 0.32 at a slope of 0.635. Cimetidine (H2 antagonist) had no effect on histamine-induced contractions. Serotonin (10(-9) to 10(-8) mol/l) significantly potentiated the contractile effect of histamine. The possible implications of the interaction between both amines in the regulation of placental blood flow is discussed.
The absence of one umbilical artery of single umbilical artery (SUA) is one of the most common congenital malformations in man. This vascular anomaly of the umbilical cord is frequently associated with other congenital malformations as well as some adverse perinatal events such as intrauterine growth retardation (IUGR), premature delivery, and increased perinatal mortality. Five cases of SUA detected prenatally by ultrasound are reported here in detail, including the first reported case in a twin gestation. None of the 5 affected infants had associated anomalies, but 2 cases of intrauterine growth retardation (IUGR) and 1 stillborn infant were noted in this series. An umbilical vein/umbilical artery ratio less than 2 was invariably found in all cases, making this observation another useful sonographic characteristic to use in the antenatal detection of SUA. Since the umbilical cord can be easily seen prenatally by ultrasound, and SUA is recognized as an important index for detecting congenital malformations, examination of the umbilical cord for the absence of one umbilical artery is an extremely valuable tool in prenatal diagnosis. The prenatal detection of SUA demands an extensive search for associated anomalies and a close surveillance of fetal well-being, since these fetuses have a high risk of fetal death or IUGR. Sonologists and sonographers should be aware of the possibility of SUA, especially in those cases associated with congenital malformations or IUGR.
We report the use of ultrasonography to make the diagnosis of a calcified uterine leiomyoma in a 31 year old woman. After hysterectomy, the diagnosis was confirmed by histopathology.
The relationship between ultrasonographic detection of fetal vernix and visual assessment of amniotic fluid (AF) and fetal pulmonary maturity evaluated by the "shake test" was studied in 73 high-risk patients undergoing amniocentesis for obstetrical indications. The AF was classified as type I, type II, and type III, depending on the subjective amount of vernix detected. Ultrasound predicted correctly 7 out of 11 cases of type I AF (64%), 14 out of 22 cases of type II AF (64%), and 38 out of 40 cases of type III AF (95%). When ultrasonography detected type I AF the "shake test" was negative in all cases, whereas if type II or type III were found, the "shake test" was positive in 40% and 86%, respectively. Our results suggest that sonographic detection of type I AF is associated with immaturity, thus amniocentesis should be avoided in such cases. Conversely, if a type III AF is detected a mature fetus is found in almost 90% of the cases. The observation of AF detecting fetal vernix during third trimester sonography is a simple manoeuver that can help to avoid the use of amniocentesis, an invasive procedure associated with some serious fetal and maternal complications.
The authors studied the correlation between optical density at 650 nm (OD650) and phosphatidylglycerol (PG) in 52 samples of amniotic fluid obtained by amniocentesis in which the shake test was negative 22 out of 52 samples (42.3%) had detectable amounts of PG (> or = 2%). Our results clearly demonstrate that OD650 is unable in predicting the presence of absence of PG in those immature samples of amniotic fluid according to the shake test.
Oxytocin was injected into the umbilical vein in 8 patients whose third stage of labor was complicated by retention of the placenta. The placenta was delivered in all patients within 3 min after the injection, avoiding thus the need for manual removal. This method seems to be effective, quick and safe in the management of retained placenta, and decreases the risks associated with the use of anesthesia and puerperal complications such as infection or trauma to the uterus.
A case of combined intrauterine and extrauterine pregnancy diagnosed by sonography is reported. Both viable intrauterine and ectopic fetuses were demonstrated by real-time sonography. The importance of careful sonographic examination of adnexal region in all symptomatic patients with first trimester pregnancy or with some predisposing factors for combined pregnancy is emphasized.
The effect of isoproterenol (ISO), norepinephrine (NE) and phenylephrine (PHE) on electrically-induced contractions of mice uterine horns was studied during pregnancy. At the different times of gestation adrenergic agonists always inhibited uterine contractions in the following rank order of potency: ISO greater than NE greater than PHE. Cumulative dose-response curves constructed for the effect of these amines during diestrous, and at days 3-7, 10-15, 17-21 of gestation, showed that EC50 values increased gradually as term approached, which could imply a lower capacity of the uterus to respond to adrenergic drugs. Some likely explanations for this phenomenon are proposed. It is suggested that this lower response to catecholamines at the end of pregnancy could be a cause for the reduced success of beta 2-adrenergic drugs to stop premature labor.
The umbilical cord normally consists of three vessels, two arteries and one vein. The absence of one umbilical artery or single umbilical artery (SUA) has been associated with some adverse perinatal events, such as low birth weight, prematurity, congenital malformations and perinatal mortality. The authors present 12 cases of SUA confirmed by histologic examination and the principal maternal and perinatal features of these cases are analyzed. In our study there were a prematurity rate of 58%, a low birth weight rate of 66% and a perinatal mortality rate of 580/1000. Among our patients, 42% of the infants with SUA had major congenital malformations. An accurate examination of the umbilical cord at delivery is suggested, mainly because SUA is an important index to detect associated congenital malformations.