Plasma endothelin, atrial natriuretic peptide (ANP) and uterine and umbilical artery flow velocity waveforms in hypertensive pregnancies

330

Citations from the Literature

patients with superimposed preeclampsia were treated with 40 mg/day oral nifedipine. Results: Erythrocyte aggregation was increased in all the hypertensive pregnant patients compared with the normotensive pregnant controls, regardless of both the onset (chronic or pregnancy-induced) of hypertension and the status of plasma macromolecules. Antihypertensive treatment with labetalol significantly reduced the aggregability of erythrocytes, whereas treatment with nifedipine reverted it to normal. Conclusions: Increased erythrocyte aggregation may be due to either conformational changes of the membrane occurring during hypertension or a redistribution of the ionic charges on the two surfaces of the membrane. The effect of nifedipine by restoring the ionic charges may be due to this latter event. Evidence against a patbogeuetic role for endoWin in preeclampsia Benigni A; Orisio S; Gaspari F; Frusca T; Amuso G; Remuzzi G Mario Negri Institute, Pharmacological Gavazzeni II, 24100 Bergamo. ITA

Research,

Via

BR J OBSTET GYNAECOL 1992 99/lO (798-802) Objective: To assess whether increased placental or systemic endothelin synthesis has a pathogenic role in pre-eclampsia (gestational proteinuric hypertension). Design: Prospective observations study. Subjects: I9 women with pre-eclampsia and 10 healthy pregnant women were studied. All were in the last trimester. Main outcome measures: Preproendothelin-l gene expression by Northern blot analysis and generation of endothelin- I precursor, big-endothelin-1 , and endothehn isoforms, namely endothelin-I, 2 and 3, were assessed by specific radioimmunoassays, in placental tissue. Plasma endothelin-I levels and urinary excretion of big-endothelin-I and endothelin-1 were measured. Results: Placental preproendothelin-1 gene expression and immunoreactive big-endothelin-l and endothelin-I, 2 and 3, were comparable in placental tissue from pre-eclampsia and normal pregnant women. Plasma levels of endothelin-I did not differ between pre-eclampsia and normal pregnancies. In contrast, urinary excretion of endothelin-1, which is likely to reflect the renal synthesis of the peptide, was significantly decreased in pre-eclamptic, as compared with normal pregnant women. This was not due to a decreasd renal generation of endothelin-I precursor, since urinary excretion of big-endothelin-1 did not differ between pre-eclamptic and normal pregnancies. These data suggest an increased renal endothelin-I breakdown in pre-eclampsia. Conclusions: Endothelin is unlikely to play a role in the pathogenesis of preeclampsia. Instead, an increased renal breakdown may have a role in limiting the negative effects of other vasoactive factors on the renal circulation. Magnesiumpyrrolidow carboxylate infusion reduces angiotensin II ptessot respouse in pregnant women at risk for hypertension Tranquilli AL; Mariani ML; Mazzanti L; Valensise H; Garzetti GG; Romanini C Viale delta Vittoria 43, 60123 Ancona. ITA

AM J OBSTET GYNECOL 1992 167/4 I (885-888) Int J Gynecol Obstet 41

Objective: Our objective was to investigate the possible restoring action of magnesium on vascular sensitivity to angiotensin II in pregnancy. Study design: We studied intraplatelet free calcium and the pressor response to angiotensin II in 10 primigravid women (28 to 32 weeks’ gestation) at risk for pregnancy induced hypertension on the basis of altered uteroplacental blood velocity waveforms at 20 weeks’ gestation, before and after the infusion of 1 gm of magnesium pyrrolidone carboxylate. After the effective pressor dose was achieved or a maximum of 32 ng/kg per minute was reached, we infused 1gmmagnesium pyrrolidone carboxylate and repeated the test. Intraplatelet free calcium was measured by means of fluorescent probes at the beginning and the end of both tests. Results: Six women were classified as refractory to angiotensin II and four as sensitive (effective pressor dose < 10 “g/kg per minute). After magnesium pyrrolidone carboxylate infusion, the four sensitive women became refractory and the effective pressor dose was significantly enhanced to 32 in all six refractory women. Intracellular free calcium increased significantly during the first angiotensin II infusion, whereas after magnesium pyrrolidone carboxylate administration it did not change significantly. Conclusions: Magnesium pyrrolidone carboxylate enhances the vascular refractoriness and intracellular free calcium mediates the pressor response to angiotensin II in pregnancy. Plasma endotheliu, atria1 oatriuretic peptide (ANP) and uterine and umbilical artery flow velocity waveforms in hypertensive preguaucies Lumme R; Laatikainen T; Vuolteenaho 0; Leppaluoto J Department of Obstetrics/Gynecology, University Central Hospital, SF-90220 Oulu. FIN

BR J OBSTET GYNAECOL 1992 9919 (761-764) Objective: To investigate the relation between concentrations of endothelin and atrial natriuretic peptide (ANP) in maternal plasma and vasospasm in the uterine and umbilical arteries as detected by duplex pulsed color Doppler ultrasonography in hypertensive pregnancies. Design: An observational study. Subjects: 32 women admitted consecutively to hospital with pregnancy induced hypertension (seven without poteimiria and 25 with proteinuria) and 78 healthy pregnant women examined at 28-40 weeks gestation. Main outcome measures: Systolic/ diastolic (S/D) ratio in flow velocity waveforms (FVWs) and plasma concentrations of endothelin and ANP in the 32 women with pregnancy induced hypertension; plasma concentrations of endothelin and ANP in 78 healthy pregnant women (controls). Results: Pathological FVWs suggesting vasospasm in the uterine or umbilical artery, or both arteries, were found in I2 women with hypertension. Plasma ANP was significantly higher (P= 0.03) in the women with hypertension and pathological FVWs (median 23.0, range 10.1-52.8 pmohl) than in those with hypertension and normal FVWs, (median 13.8, range 5.3-42.3 pmolfl) but corresponding plasma endothelin levels did not show any significant difference (median 1.63, range 0.51-3.33 pmohl and median 1.38, range 0.51-3.51 pmohl, respectively). Conclusion: Focal release of endothelin from the vascular endothelium is thought to cause vasospasm

Citations from the Literature

in pregnancy induced hypertension but this does not seem to increase the concentration of endothelin in the maternal peripheral plasma, probably because of its rapid disappearance from the blood circulation. As ANP dilates the blood vessels, the increase of its release in hypertensive pregnancies may be a compensatory mechanism against vasospasm.

of astlwa and pwiwtal outcome Perlow JH; Montgomery D; Morgan MA; Towers CV; Port0 M Severity

Maternal-Fetal Medicine, Phoenix Perinatal Associates, 1300 N. 12th St., Phoenix, AZ 85006. USA

AM. J OBSTET GYNECOL 1992 167/4 I (963-967) Objective: Our objective was to determine the impact of asthma and its severity, as determined by medication requirements, on perinatal outcome. Study design: A case-controlled study was conducted. Among 30,940 live births at Long Beach Memorial Medical Center Women’s Hospital, 183 deliveries occurred between Jan. 1,1985, and Dec. 31,1990, that were coded for the diagnosis of asthma. Eighty-one that required the chronic use of medications to control their disease were identified. Thirty-one patients were steroid dependent and 50 were non-steroid-medication dependent. A control group was randomly selected (excluding maternal transports), and selected perinatal variables were compared between groups. Results: When compared with controls, steroid-dependent asthmatics were at significantly increased risk for gestational (1.5% vs. 12.9%) and insulin-requiring diabetes (0% vs. 9.7%). Preterm delivery and preterm premature ruptured membranes occurred signifrantly more often in both asthmatic groups. Overall cesarean section rate was significantly increased in the nonsteroid-medicationdependent asthmatic group when compared with controls (56.0% vs. 30.0%). Delivery by primary cesarean section was significantly more common in the steroiddependent group (38.7% vs. 19.2%), and a strong trend was noted among the non-steroid-medication-dependent patients (34.0% vs. 19.2%). Cesarean delivery for fetal distress was also more common in these two asthmatic groups. Neonates born to both groups of asthmatic pregnant women were significantly more likely to be of birth weight <2500 gm but did not have an increased frequency of intrauterine growth restriction. NO significant differences in low 5-mitt Apgar scores were found; however, neonates born to both steroid-dependent and nonsteroid-medication-dependent asthmatics were significantly more likely to be admitted to the neonatal intensive care unit (39.0% and 22.0% vs. 7.7%). Preterm delivery and low birth weight were complications observed significantly more often in the steroid-dependent asthma group when compared with the non-steroid-medication-dependent group (54.8% vs 14.0% and 45.2% vs. 14.0%). Conclusions: Perinatal outcome is compromised in the pregnancy complicated by chronic medicationdependent asthma. The extent is variable and is associated with disease severity, as measured by medication requirements. Perinahl outcome in pregnancy complicated by massive obesity Perlow JH; Morgan MA; Montgomery D, Towers CV; Porto M

331

Maternal-Fetal Medicine, Phoenix Perinatal Associates, 1300 N. 126th St., Phoenix, AZ 85006, USA

AM J OBSTET GYNECOL 1992 16714I (958-962) Objective: Our objective was to determine the impact of massive obesity during pregnancy, defined as maternal weight >300 pounds, on perinatal outcome. Study design: A casecontrolled study was conducted. Between Jan. I, 1986, and Dec. 3 1, 1990, 111 pregnant women weighing > 300 pounds who were delivered at Long Beach Memorial Women’s Hospital were identified with a perinatal data base search. A control group matched for maternal age and parity was studied, and perinatal variables were compared between groups, To control for potential confounding medical complications, massively obese patients with diabetes and/or chronic hypertension antedating the index pregnancy were excluded from the obese group, and the data were reanalyzed. The Student t test chi,, and Fisher’s exact statistical analysis were used where appropriate. Results: Massively obese pregnant women are significantly more likely to have a multitude of adverse perinatal outcomes, including primary cesarean section (32.4% vs. 14.3%, P = 0.002), macrosomia (30.2% vs. 11.6%, P= O.OOOl), intrauterine growth retardation (8.1% vs. 0.9%, P = 0.03) and neonatal admission to the intensive care unit (15.6% vs. 4.5%, P = 0.01). They also are significantly more likely to have chronic hypertension (27.0% vs. 0.9%, P < 0.0001) and insulindependent diabetes mellitus (19.8% vs. 2.7%, P = O.OOOl).However, when those massively obese pregnant women with diabetes and/or hypertension antedating pregnancy are excluded from analysis, no statistically significant differences in perinatal outcome persisted. Conclusion: Massively obese pregnant women are at high risk for adverse perinatal outcome; however, this risk appears to be related to medical complications of obesity.

FERTILITY, STERILITY Defective fmwtion of a ? ongenomic ? progesterone receptor as a sole sperm anomaly in infertile patients

Tesarik J; Mendoza C Reproductive Biology/Medicine Center, American Hospital of Paris, 63 Boulevard Victor Hugo, 92202 Neuiliy sur Seine, FRA

FERTIL STERIL 1992 58/4 (793-797) Objective: To compare the function of a novel nongenomic progesterone (P) receptor on the human sperm surface (mediating the P-induced acrosome reaction) in spermatozoa from fertile donors and from infertile patients. To examine the possible implication of defective P receptor function as an etiologic factor in unexplained male infertility. Design: Progesterone binding and P effects were assessed in sperm from infertile patients and compared with corresponding parameters for sperm from healthy donors. Setting: Private hospital, medical research center, and a university-based andrological laboratory. Patients, Participants: Sperm samples were from infertile patients (no pathology detected in their wives) attending our infertility clinic and from healthy sperm donors. Interventions: None. Main Outcome Measures: Progesterone binding sites were visualized with a fluorescein-labeled protein-P conjugate. Indo I-AM (a fluorescent indicator of intracehuiar free Ca*+) Int J Gynecol Obstet 41