Nathan J. Hoeldtke

Fetoplacental vascular tone during fetal circuit acidosis and acidosis with hypoxia in the ex vivo perfused human placental cotyledon

OBJECTIVES Our purpose was to determine the effects of acidosis and acidosis-hypoxia on fetoplacental perfusion pressure and its response to angiotensin II. STUDY DESIGN Perfused cotyledons from 14 placentas were studied with either an acidotic fetal circuit perfusate (n = 7) or an acidotic-hypoxic fetal circuit perfusate (n = 7). Each cotyledons fetal vasculature was initially perfused under standard conditions and bolus injected with 1 x 10(-10) moles of angiotensin II. Fetoplacental perfusate was then replaced with either an acidotic medium (pH 6.90 to 7.00 and Po2 516 to 613 mm Hg) or an acidotic-hypoxic medium (pH 6.90 to 7.00 and Po2 20 to 25 mm Hg) followed by an angiotensin II injection. The vasculature was subsequently recovered with standard perfusate and again injected with angiotensin II. Perfusion pressures within each group were compared by one-way analysis of variance, and results were expressed as mean pressure +/- SEM. RESULTS Resting fetoplacental perfusion pressure did not change when the fetal circuit perfusate was made acidotic (28 +/- 1 mm Hg vs 25 +/- 2 mm Hg) or acidotic-hypoxic (26 +/- 2 mm Hg vs 25 +/- 2 mm Hg). The maximal fetoplacental perfusion pressure achieved in response to angiotensin II did not differ with an acidotic perfusate (41 +/- 2 mm Hg vs 38 +/- 1 mm Hg) or with an acidotic-hypoxic perfusate (39 +/- 2 mm Hg vs 36 +/- 2 mm Hg). CONCLUSIONS In the perfused placental cotyledon fetoplacental perfusion pressure and pressor response to angiotensin II are not affected by fetal circuit acidosis or acidosis-hypoxia. This suggests that neither fetal acidosis nor fetal acidosis combined with hypoxia has a direct effect on fetoplacental vascular tone.

The effect of membrane sweeping on prelabor rupture of membranes: a randomized controlled trial.

OBJECTIVE: To estimate if membrane sweeping increases the rate of prelabor rupture of membranes. METHODS: This randomized trial of term, uncomplicated pregnancies included 300 patients. Patients were randomly assigned into sweep or no-sweep groups, with patients and delivering providers blinded to group allocation. Only the examining provider in the clinic was unblinded to group allocation. Membranes were then swept or not swept at each weekly visit from 38 weeks of gestation onward, depending on the randomization. Data collected included parity, cervix examination at each visit, estimated gestational age at delivery, rupture of membranes, and maternal or fetal complications. RESULTS: A total of 162 patients were randomly assigned to the membrane sweep group and 138 to the no-sweep group. There was no difference in baseline characteristics or obstetric and neonatal outcomes between the groups. The average gestational age at delivery and induction rate were not different. The overall prelabor rupture of membranes rate was not significantly higher in the membrane sweep group (12% compared with 7%) (P=.19); however, patients with a cervix more than 1 cm dilated at time of membrane sweeping were more likely to have prelabor rupture of membranes if they were in the membrane sweep group (9.1% compared with 0%; relative risk 1.10, 95% confidence interval 1.03–1.18). CONCLUSION: No benefit in gestational age at delivery or reduction of postmaturity occurred from membrane sweeping. Although the overall prelabor rupture of membranes rates were similar, patients with membrane sweeping occurring at more than 1 cm cervical dilation may be at increased risk of prelabor rupture of membranes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00294242 LEVEL OF EVIDENCE: I

Adrenomedullin concentrations in umbilical cord plasma of uncomplicated term pregnancies

OBJECTIVE The studys objective was to determine whether there is a difference in the plasma concentration of adrenomedullin, a hypotensive peptide, between arterial and venous umbilical cord blood of uncomplicated gestations with vaginal delivery. STUDY DESIGN Arterial and venous umbilical cord blood was obtained immediately after vaginal delivery of 44 term infants with uncomplicated antepartum and intrapartum courses. Radioimmunoassay was performed to assess adrenomedullin concentrations in the plasma. The paired t test was used to compare arterial and venous concentrations. Significance was set at P < .05. RESULTS Mean +/- SE adrenomedullin concentrations were 178.7 +/- 4.7 pg/mL and 190.6 +/- 6.3 pg/mL for arterial and venous cord plasma, respectively. The difference between the 2 concentrations was not significant (11.8 pg/mL, P = .09). CONCLUSION Arterial and venous umbilical plasma concentrations of adrenomedullin do not differ significantly in uncomplicated gestations terminating with uncomplicated vaginal deliveries. This suggests that in the normal state there is neither net production nor net clearance of adrenomedullin in the placenta.

Intracranial cavernous angioma initially presenting in pregnancy with new-onset seizures ☆ ☆☆ ★ ★★

A case of an intracranial cavernous angioma, which presented with headaches and seizures in a pregnant patient, is described. Diagnosis was established with magnetic resonance imaging. A computer-assisted literature search uncovered no previously reported case of intracranial cavernous angioma initially presenting during pregnancy.