Biomedical subjects

D Ronderos-Dumit

Publications and source records attributed to D Ronderos-Dumit.

7 recordsLinked to original sources

PubMed2006

Endoscopic release of limb constriction rings in utero.

Amniotic band syndrome is a sporadic condition that may result in constriction bands, amputation and multiple craniofacial, visceral and body wall defects. It occurs in 1/1,200 to 1/15,000 live births. Most cases present with multiple congenital anomalies that are incompatible with life. A small group of fetuses shows isolated limb constrictions that may cause severe limb dysfunction or limb amputation if left untreated. Successful in utero surgical lyses of constriction rings have been reported. We report a case of constriction amniotic bands involving both legs and compromising blood flow to the distal extremity. The constriction ring was successfully released by a minimally invasive endoscopic surgical technique avoiding severe limb dysfunction or foot amputation.

Amniotic Band Syndrome↗

PubMed1994

The effect of neuromuscular blockade on human fetal heart rate and its variation.

OBJECTIVE: To determine the effect of neuromuscular blockade on fetal heart rate and its variation. DESIGN: Case control study. SETTING: Tertiary referral fetal medicine unit in a London teaching hospital. SUBJECTS: Forty women with rhesus iso-immunisation requiring an intravascular fetal blood transfusion between 28 and 34 weeks gestation. INTERVENTION: Intravascular injection of pancuronium to the fetus prior to fetal blood transfusion in 20 cases. MAIN OUTCOME MEASURES: Comparison between the group receiving pancuronium and the control group with regard to differences in perceived fetal activity and computer derived numerical indices of fetal heart rate and fetal heart rate variation after fetal blood transfusion. RESULTS: After transfusion in the control group, there were fewer perceived fetal movements, a small reduction in fetal heart rate but no differences in number of fetal heart rate accelerations or measures of fetal heart rate variation. In the study group, pancuronium produced no change in fetal heart rate despite a virtual abolition of perceived fetal movements and fetal heart rate accelerations. Measures of fetal heart rate variation were reduced by 60%. Comparison of the pre- to post-transfusion changes between the two groups showed significant differences for all fetal heart rate indices. CONCLUSION: Fetal activity accounts for more than half the measured variation of the human fetal heart rate.

Blood Transfusion, Intrauterine↗

PubMed1992

Intra-amniotic pressures following vaginal gemeprost prior to first and second trimester termination of pregnancy.

Intra-amniotic pressures were measured following 1 mg gemeprost for cervical preparation before first trimester vacuum aspiration (n = 10) and following 2 mg gemeprost before second trimester dilatation and evacuation (n = 15). Twenty-five women, matched for gestational age and parity, who did not receive gemeprost served as controls. Compared to control values (2-8 mmHg), basal intra-amniotic pressure (IAP) was significantly increased after 1 mg and 2 mg of gemeprost (median 20.0, range 4-45 mmHg, median 20.0, range 8-60 mmHg, respectively). Uterine contractions were recorded in 8 of 10 subjects after 1 mg (median delta IAP 28.0, 95% CI 10.0-42.6 mmHg) and 14 of 15 subjects after 2 mg (median delta IAP 52.5, 95% CI 26.7-60.3 mmHg). Gemeprost produces an increase in uterine contractility which may be additional to cervical softening properties and which may be responsible for the adverse effects of pain and bleeding experienced by some women prior to termination.

Abortion, Induced↗

PubMed1992

Normal amniotic pressure throughout gestation.

OBJECTIVE: To characterize amniotic pressure (AP) in pregnancies with normal amniotic fluid volume. DESIGN: Observational study, mainly cross-sectional. SETTING: Fetal medicine unit within a tertiary referral hospital. SUBJECTS: Patients undergoing transamniotic invasive procedures in whom amniotic fluid volume was subjectively assessed as normal on ultrasound. Those beyond 16 weeks with a deepest vertical pool on ultrasound less than 3.0 or greater than 8.0 cm were excluded. Overall 194 pregnancies were studied on 232 occasions between 7 and 38 weeks gestation. INTERVENTIONS: Manometry readings referenced to the top of the maternal abdomen were obtained via a fluid-filled line from the needle hub and either connected to a pressure transducer (n = 190) or held vertically against a ruler (n = 42). MAIN OUTCOME MEASURES: AP in mm Hg, AP corrected for gestational age (z scores), semi-quantitative ultrasonic indices of amniotic fluid volume, clinical variables. RESULTS: AP in singleton pregnancies increased with advancing gestation (P less than 0.001), and the sigmoid-shaped regression curve plateaued in the mid-trimester. AP z scores were not influenced by volume-related phenomena such as twin gestation, the deepest vertical pool, or amniotic fluid index, nor by maternal age, parity, gravidity, fetal sex, or subsequent spontaneous preterm delivery. CONCLUSIONS: These findings suggest that AP is not principally determined by intrauterine volume. We speculate that AP, which reflects change in uterine tension as a function of radius, may instead be determined by gestation-specific anatomical and hormonal influences on gravid uterine musculature. A reference range for AP has been constructed for use in amnioinfusion and amnioreduction procedures.

Amniotic Fluid↗

PubMed1992

Relief of presumed compression in oligohydramnios: amnioinfusion does not affect umbilical artery Doppler waveforms.

The suggestion that amnioinfusion improves umbilical artery Doppler indices of downstream resistance in oligohydramnios by relieving cord compression was investigated by obtaining waveforms before and immediately after amnioinfusion in 16 pregnancies with severe oligohydramnios. There was no significant difference in the change in umbilical artery pulsatility index (PI) between 11 pregnancies in which amniotic fluid volume was restored (mean delta PI = -0.07, 95% confidence interval -0.17 to +0.07), and 5 pregnancies in which immediate vaginal leakage of infused fluid prevented restitution of amniotic fluid volume. Fetal heart rate did not change significantly in either group. End-diastolic frequencies did not return with restitution of amniotic fluid volume in the 2 pregnancies in which they were absent before infusion (absent in 1, reverse in 1). This study suggests that restitution of amniotic fluid volume in human pregnancies complicated by severe oligohydramnios does not acutely alter the umbilical artery PI.

Amnion↗

PubMed1991

Uterine-peritoneal amniotic fluid leakage: an unusual complication of intrauterine shunting.

Bilateral pleuroamniotic shunting was performed at 33 weeks' gestation in a fetus with bilateral hydrothorax, hydrops, and gross polyhydramnios. The procedure was successful, but acute amniotic fluid leakage into the maternal peritoneal cavity occurred soon after. This produced marked maternal discomfort and transient oligohydramnios, with consequent fetal distress. Expectant management was adopted in view of fetal lung immaturity. Resolution of maternal ascites occurred within 24 hours and the fetal heart rate normalized as amniotic fluid reaccumulated. The pregnancy progressed uneventfully thereafter.

Adult↗

PubMed1991

Diagnostic and therapeutic transabdominal amnioinfusion in oligohydramnios.

We report our experience with 92 antenatal amnioinfusion procedures. In order to facilitate ultrasound visualization, a diagnostic infusion was attempted at a median of 22 weeks (range 16-36) in 61 pregnancies with oligohydramnios in the absence of ruptured membranes on clinical examination. The procedure was successful in 58 (95%). Infusion (mean volume 181 mL, range 40-64) significantly increased (P less than .001) the deepest pool of amniotic fluid to a mean of 3.2 cm. Suspected fetal anomalies were then confirmed in 27 of 30 cases, whereas kidneys were clearly demonstrated in three fetuses suspected of renal agenesis. In addition, previously unsuspected anomalies were identified in five. Vaginal leakage indicating ruptured membranes occurred in 16 women. Leakage occurred in zero of 24 patients with, compared to 16 of 35 without, fetal urinary disorders (chi 2 = 15.1, P less than .001), which does not support the recent suggestion that amnioinfusion causes rather than unmasks rupture of the membranes. Membranous detachment was observed by ultrasound in 13 patients, 11 of whom leaked vaginally. Information obtained at amnioinfusion led to a change of etiologic diagnosis in eight (13% of subjects). Forty serial infusions were performed in nine women as a pilot study to prevent oligohydramnios sequelae. There were no skeletal deformities; three neonates survived, and five of the six perinatal deaths had normal lung-body weight ratios. Overall, only two of 89 infusions (2.2%) were complicated by clinical amnionitis. Our findings support a role for amnioinfusion in oligohydramnios.

Amnion↗