Ezra C. Davidson

Procoagulant properties of amniotic fluid.

Abstract Amniotic fluids from about 50 patients from 12 to 40 weeks of gestation have been obtained by amniocentesis and studied for procoagulant material. Some of the fluids were fractionated and concentrated by ammonium sulfate precipitation. The fluids and concentrates were able to shorten the recalcification time of normal plasma or those deficient in factors XI, IX, VIII, and VII. Plasma deficient in factor X or V was not shortened significantly. These results and others with the use of prothrombin, Stypven, and partial thromboplastin times have indicated that this procoagulant from amniotic fluid is an activator of factor X and may function in a manner somewhat similar to Russells viper venom (RVV). The factor X activator has been roughly quantitated in terms of RVV equivalents and appears to increase with the increasing period of gestation. The amount of procoagulant in clear amniotic fluid is probably insufficient to cause significant intravascular coagulation in the event of an amniotic fluid infusion but may be sufficient to promote primary hemostasis in the uterus following delivery.

Vascular reactivity to angiotensin II infusion during gestation

We serially tested 26 healthy, young, nulliparous patients, while they were maintained in the left lateral recumbent position, during a four-week interval (29 to 32 weeks), with progressive increments of angiotensin-II (A-II) 2.0 to 15.0 ng. per kilogram per minute). Blood pressure was recorded with an ultrasound device. All patients were followed through delivery. Three patients (12 per cent) developed pregnancy-induced hypertension (PIH); only one of these demonstrated enhanced vasoreactivity prior to PIH. Conversely, 13 patients who did not develop PIH demonstrated enhanced vasoreactivity at least once during the testing interval. Comparison of results obtained from one week to the next was evaluated in 57 test pairs; discordant data, i.e. reaction to less than 8 ng. per kilogram per minute one week and nonreaction the next, was observed in 17 pairs (30 per cent). We conclude that assessment of the risk of PIH, with the use of the diastolic pressor response to infused A-II, is unreliable.

Coagulation studies in the hypertensive toxemias of pregnancy

Abstract Certain indices of the coagulation-fibrinolytic systems, studied in hypertensive pregnant patients, demonstrated changes consistent with mild disseminated intravascular coagulation. The changes were more marked in severe acute hypertension and included low platelet count, lower factor V, and prolongation of prothrombin, Stypven, partial thromboplastin, and thrombin times. There was acceleration of the retarded thromboplastin-generation test (RTGT). The plasminogen levels were decreased, suggesting a secondary response to intravascular coagulation since no increase in active fibrinolysis was observed. Uncomplicated chronic hypertension revealed certain trends suggesting intravascular coagulation which probably explain or contribute to the much higher incidence of acute toxemia in this group. These include high fibrinogen, marked acceleration of RTGT, and high levels of plasminogen and fibrinolytic inhibitors.

The racial disparity in infant mortality.

From the standpoint of both science and social policy, it is important to focus on the more than twofold disparity in mortality between black and white infants in the United States. This disparity ...

The age extremes for reproduction: current implications for policy change.

The changing demographic features of births in the United States include an increasing number of older women and a decreasing number of adolescents giving birth. Births in adolescents have lower risks than those in women more than 34 years of age and probably of those more than 30 years of age. There is an increase in complicated pregnancies in the United States, related, no doubt in part, to the above. Older women require more costly, high-technology prenatal care, such as genetic counseling, genetic antenatal diagnosis, amniocentesis, ultrasonography, and electronic fetal heart rate testing. The financing of health care needs to recognize these changes. Detailed studies of the economics of perinatal care, more specific to patient population mix and complication-treatment patterns are needed to establish priorities with the payment system to assure appropriate care.

Cutaneous Pressure Pulse Contours Associated with Chronic Hypertension in Pregnancy

This report describes the association of cutaneous pressure pulse waveforms, mean arterial blood pressures, and neonatal birthweights of 27 chronic hypertensive patients. The infant weight percentiles were higher than the median when the pressure pulses showed good compliance, and lower when there was poor compliance

An analysis of adolescent health care and the role of the obstetrician-gynecologist

There has been documented an increase in sexual activity in adolescents in the United States and a resultant increase in related health care for pregnancy, abortion, contraception, and sexually transmitted disease. This study characterizes some elements of these services and the attitudes of physicians in regard to adolescent sexuality. The Female Datafile from the University of Southern California--Mendenhall Manpower Study and the survey of the American College of Obstetricians and Gynecologists on adolescent pregnancy suggest that obstetrician-gynecologists provide a large portion of health care to both adult (14.6%) and adolescent women (7.7%); that reproductive health care is primarily provided by obstetrician-gynecologists to female adolescents (76%); that adolescent care is generally less comprehensive in private practice than is recommended; that obstetrician-gynecologists could be the primary care physicians for both adult and adolescent women, since they are increasingly the medical contact point, especially after age 14; and, in view of the negative attitudes of physicians to adolescent sexual practices, that some training or reorientation will probably be necessary to prevent judgmental approaches from interfering with the physician-adolescent patient relationship.

Sampling the fetoplacental circulation: IV. Preliminary experience in the pregnant baboon (Papio cynocephalus)☆☆☆★

Preliminary experience with fetoscopy and fetoplacental blood sampling in 23 midtrimester pregnant baboons demonstrated the procedure to be successful in 19 cases (83%); seven serious complications (30%) developed, most of which might well have been avoided with operative experience and other complimentary procedures.