Henk C.S. Wallenburg

Outcome after transabdominal cervicoisthmic cerclage.

OBJECTIVE: To estimate benefits and risks of transabdominal cervicoisthmic cerclage in women with cervical insufficiency in whom transvaginal cerclage is considered surgically unfeasible. METHODS: This was an observational cohort study with historical controls of 101 pregnancies after transabdominal cervicoisthmic cerclage in 101 women with a classic history of cervical insufficiency and severe cervical defects precluding transvaginal cerclage. RESULTS: Median gestational age at elective transabdominal cerclage (n = 95) was 14 (range 12–16) weeks and at emergency cerclage (n = 6) was 18 (range 17–22) weeks. Perioperative complications were blood loss 500 mL or more (n = 3) and rupture of membranes (n = 2). Patients were delivered by cesarean. Before cerclage 76% (95% confidence interval [CI] 70.2–81.1%) of births occurred before 32 weeks of gestation; total neonatal survival was 27.5% (95% CI 22.5–33.8%). After transabdominal cervicoisthmic cerclage 7% (95% CI 2.9–13.9%) of births took place before 32 weeks of gestation, and total neonatal survival was 93.5% (95% CI 85.5–96.6%). CONCLUSION: In women with a classic history of cervical insufficiency and a traumatized cervix that precludes transvaginal cerclage, transabdominal cervicoisthmic cerclage is associated with successful outcome in the absence of procedure-related major complications. LEVEL OF EVIDENCE: II-2

Maternal and fetal cardiovascular responses to strenuous bicycle exercise

In a longitudinal study we investigated some cardiovascular responses to strenuous bicycle exercise in 33 healthy women during pregnancy and the postpartum period. The exercise electrocardiogram demonstrated depression of the ST segment in 12% of women in the absence of clinical signs of ischemia, and the incidence of these changes was unaffected by pregnancy. In spite of slightly different blood pressures at rest during the first and second trimesters of pregnancy, the blood pressure response to exercise at approximately 75% Vo2max was virtually unaffected by pregnancy. After a maximal bicycle test, the fetal heart rate was increased by an average of 4 beats/min, without a change in pattern. Tocodynamometry suggested a transient increase in uterine activity after maximal exercise in 6% of the tests. These findings support the view that strenuous exercise of limited duration is not harmful to the healthy mother and fetus.

Fetal heart rate and uterine contractility during maternal exercise at term.

OBJECTIVE Our aim was to assess the physiologic response of human fetal heart rate and uterine contractility to moderately strenuous maternal exercise. STUDY DESIGN We measured fetal heart rate and intrauterine pressure with the use of internal monitoring before, during, and after maternal exercise at a heart rate of 140 beats/min on a cycle ergometer in 30 term women admitted for elective induction of labor. The fetal heart rate tracings were assessed by three observers and were classified according to Fischer et al. and Nijhuis et al., and the frequency and intensity of uterine contractions were determined. RESULTS Fetal outcome was good in all cases. There were no significant differences in Fischer scores between rest, exercise, and recovery periods. The fetuses displayed a heart rate pattern A and B, indicative of behavioral states 1F or 2F, 85% of the time, with state changes apparently independent of exercise. Uterine activity increased significantly during the exercise period, with a 5.5-fold increase in contraction frequency and a fourfold increase in time-pressure integral compared with rest, with rapid recovery after the exercise. CONCLUSION Exercise in healthy pregnant women at term does not cause a change in fetal heart rate pattern suggestive of fetal distress or a change in fetal behavioral pattern, but it does significantly increase uterine activity.

The pathogenesis of placental infarction: II. An experimental study in the rhesus monkey placenta

Abstract One to 4 uteroplacental arteries were surgically visualized and ligated in vivo in 34 pregnant rhesus monkeys, and pregnancy was allowed to continue. The placentas of 19 animals eventually became available for histologic and histochemical study after a variable but predetermined interval following ligation. Necrotic cotyledonary lesions showing the histologic and histochemical characteristics of infarction could be demonstrated in connection with ligated uteroplacental arteries. The earliest lesion was found after a 23 hour interval following ligation. It is concluded that occlusion of a uteroplacental artery leads to a lesion which is comparable with an infarct in the human placenta. In this experimental model, there appears to be no effective collateral maternal cotyledonary circulation.

Effects of a beta-adrenergic agent (metaproterenol) on uteroplacental circulation. An angiographic study in the pregnant rhesus monkey.

Abstract Placental radioangiography was performed in 13 lightly anesthetized pregnant rhesus monkeys under standardized conditions. Amniotic, aortic, and central venous pressures as well as the maternal electrocardiogram (ECG) were continuously monitored. In six experiments intravenous infusion of a small amount of metaproterenol was shown to accelerate the angiographic appearance of intervillous spurts due to vasodilatation. This effect could be partially blocked by propranolol and thus would appear to be caused by stimulation of vascular beta-adrenergic receptors. Evidence is adduced that accelerated uteroplacental circulation in this experimental model means increased uteroplacental blood flow. In analogy, administration of small amounts of a beta-adrenergic agent in cases of impaired uteroplacental blood flow due to vasospasm in man might lead to vasodilatation and consequently might improve uteroplacental flow and fetal condition.

A radioangiographic study of the effects of catecholamines on uteroplacental blood flow in the rhesus monkey.

Two placental radioangiographies were performed with a 20-min interval in ten lightly anesthetized rhesus monkeys. Amniotic and aortic pressures, as well as the maternal ECG, were continuously monitored. Norepinephrine or metaproterenol was administered in a low dose which did not cause general cardiovascular effects, prior to the second angiography. Norepinephrine appeared to cause constriction and metaproterenol, dilatation of the uteroplacental vessels. These effects could be diminished or abolished by an alpha- or beta-adrenergic blocking agent, respectively, and thus would appear to be caused by stimulation of adrenergic receptors in the uteroplacental vasculature.

Diagnosis of severe fetal cytomegalovirus infection from amniotic fluid in the third trimester of pregnancy.

rr~~~~ ARE, at present, two reports in the literature describing the isolation of cytomegalovirus (CMV) from amniotic fluid, obtained during pregnancy by means of amniocentesis.’ In both cases there was a severe CMV infection of the mother with an asymptomatic infection in the neonate. We present a case in which CMV was recovered from the amniotic fluid at 32 weeks of amenorrhea in a woman with an asymptomatic CMV infection, who was eventually delivered of an infant with a severe congenital CMV syndrome. A 19-year-old, Caucasian, primigravid woman was admitted at 30 weeks of pregnancy with the diagnosis of insufficient fetal growth. The course of pregnancy had been uneventful and, in particular, there was no history of malaise or fever during pregnancy. The uterus was about the size of a 28 weeks’ pregnancy with a single fetus in cephalic position. The biparietal diameter of the fetal head as measured by ultrasound was 6.8 cm, being far below the fifth percentile of the usual standard curve, and the fetal chest area was with 40 sq cm on the fifth percentile of our reference curve. The routine laboratory tests revealed no abnormalities, except for a slightly elevated serum bilirubin concentration (18 pmoles/L). On serologic screening for infections, the complement-fixation

Release of tumor necrosis factor-α and prostanoids in whole blood cultures after in vivo exposure to low-dose aspirin

BACKGROUND: The preventive effect of low-dose aspirin in cardiovascular disease is generally attributed to its antiplatelet action caused by differential inhibition of platelet cyclooxygenase-1. However, there is evidence that aspirin also affects release of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha). It is not known whether this is caused by direct action on the cytokine pathway or indirectly through cyclooxygenase inhibition and altered prostanoid synthesis, or both. METHODS: We assessed the capacity of lipopolysaccharide-activated leukocytes in whole blood cultures of eight healthy subjects following a single oral dose of 80 mg aspirin to release TNF-alpha, prostanoid E2 (PGE2) and prostanoid I2 (PGI2), and thromboxane A2 (TXA2). TNF-alpha and prostanoids were determined by enzyme-linked immunoassays. RESULTS: In seven subjects, TNF-alpha release in blood cultures decreased 24h after intake of aspirin. The effect of aspirin on prostanoid release was assessed in three individuals: PGE2 increased in all subjects, PGI2 increased in two and remained unchanged in one, and TXA2 was reduced in two and unchanged in one individual The presence of DFU, a specific inhibitor of cyclooxygenase 2, did not affect the reduction of TNF-alpha release by aspirin, but abolished prostanoid production in all three individuals. Conclusion: The capacity of activated leukocytes to release TNF-alpha is reduced by ingestion of low-dose aspirin, independent of changes in prostanoid biosynthesis.

Fetal and maternal concentrations of uric acid and oxypurines during labor and post partum

Concentrations of uric acid (UA) and oxypurines (OPs) were enzymatically determined in fetal scalp plasma, amniotic fluid, and maternal venous plasma simultaneously collected during oxytocin-induced labor in 19 normal term parturient patients. Values were compared with concentrations in arterial and venous cord plasma and maternal plasma drawn immediately post partum. During labor until just before delivery fetal levels of UA were significantly lower and OP concentrations were significantly higher than the corresponding maternal levels. These differences were absent when cord and maternal concentrations were compared. It is concluded that UA and OP values in cord plasma do not reflect fetal levels during labor. The cause of this discrepancy remains obscure.

Placental radioangiography as a method for the study of uteroplacental blood flow in the rhesus monkey.

Placental radioangiography was performed in lightly anesthetized, pregnant rhesus monkeys under close monitoring of vital signs. Two angiographies in the same animal performed at an interval of approximately 20 min consistently produced identical patterns but not at intervals of one or two weeks. Evidence is adduced that the parameters, calculated from the angiograms, represent indices of uteroplacental blood flow under the standardized conditions of the angiographic procedure described here. Thus, placental radioangiography constitutes a relatively simple procedure for comparative, semiquantitative studies.