Duncan E. Reid

The pathologic anatomy of eclampsia, bilateral renal cortical necrosis, pituitary necrosis, and other acute fatal complications of pregnancy, and its possible relationship to the generalized Shwartzman phenomenon.

Abstract Intravascular fibrin deposition in arterioles and capillaries throughout the body is responsible for the necrosis and hemorrhage seen in eclampsia, bilateral renal cortical necrosis, and pituitary necrosis associated with pregnancy. These cases are often accompanied by severe shock, hemorrhage, and anuria. Fibrinogenopenia and fibrinolysins develop in this group of patients. It is suggested that the mechanism behind the fibrin deposition is similar to that in the generalized Shwartzman reaction. In some cases the source of “toxin” may be a bacterial infection. In some cases, particularly those associated with toxemia of pregnancy, the “toxin” may be similar to the “menstrual toxin” described by the Smiths.

I. Intravascular clotting and afibrinogenemia, the presumptive lethal factors in the syndrome of amniotic fluid embolism

I N 1941, Steiner and Lushbaugh’ described the syndrome of amniotic fluid embolism which they considered the major cause of maternal death during labor. The chief clinical signs were dyspnea and sudden shock, and death was ascribed to the embolic effects of amniotic fluid and an associated anaphylactoid reaction. Widespread embolization of the pulmonary arterioles and capillaries by particulate matter contained in amniotic fluid were believed to be responsible for the essential pathologic lesions. The predisposing factors in the causation of this syndrome seemed to be tetanic uterine contractions, multiparity, and exceedingly large infants. Since the original description of amniotic fluid embolism, additional cases of the syndrome have been recognized and reported.2 As in the case OS Steiner and Lushbaugh’s patients, some died undelivered with the classical signs and symptoms of embolism, while others who survived the initial shock succumbed within one to three hours after delivery. In the latter group, bleeding from the mucous membranes and organ surfaces was noted, and some degree of vaginal bleeding was described which was attributed to atony of the uterus, secondary to shock. When these fatal cases are reviewed, two unexplained observations stand out. One is to the effect that the amount of mechanical blockage of the pulmonary vessels by amniotic debris is hardly suf-

The circulating red cell volume and body hematocrit in normal pregnancy and the puerperium: By direct measurement, using radioactive red cells☆

Dieckmann and Wegner,l Thomson, 2 McLennan and Thouin and Caton, Roby and associates,4 have all measured and reported plasma, whole blood, and red cell volumes during pregnancy. The studies reviewed agree that there is a progressive increase in plasma volume into the third trimester. Indirectly calculated red cell volumes revealed the same progressive increase. There are differences of opinion, however, as to whether there is a statistically significant reduction in plasma and total blood volume prior to delivery. The length of time for plasma and total blood volume to return to normal also varies in the different reports. No doubt part of the disagreement has been the result of too few determinations on the same individual. The lack of a significant number of postpartum observations, especially late postpartum determinations as compared to the prepartum period, adds to the difficulty in interpreting the gestational data. Perhaps if more investigators had used late postpartum observations for a norm rather than a nonpregnant group, the data might have been better evaluated. Rather wide variations in results were also reported. These inconsistencies were due in part to the technical limitations of the dye technique. Also, in a small series extreme individual variations, especially when compared to nonpregnant control groups, are of sufficient degree to affect an arithmetic mean. Indirectly calculated red cell volumes are subject to known inherent errors, and in individual determinations this error may be considerable. The use of nonpregnant groups as controls for comparison limits the evaluation of the data in quantitative terms.

Endotoxin shock and the generalized Shwartzman reaction in pregnancy

Abstract The clinical and pathologic findings in 7 pregnant patients with endotoxin shock have been presented. Escherichia coli was the most common infective organism. The syndrome occurred in 2 clinical situations; namely, (1) infected abortion, and (2) premature rupture of the membranes with chorioamnionitis and placentitis. The presence of bilateral renal cortical necrosis due to disseminated intravascular coagulation in 3 of these patients demonstrates that the human being is subject to the generalized Shwartzman phenomenon. A comparison between the response of the patient and that of the experimental animal to intravenous bacterial endotoxin has been made. Both showed marked alterations in the blood coagulation mechanism associated with disseminated intravascular coagulation and both exhibited profound, sometimes irreversible, shock. Animal experiments suggest that the shock is caused by a decreased venous return to the right side of the heart because of obstruction of the portal circulation by the liver. The obstruction may be due to vasospasm and thrombosis of the central veins of the liver. Acute cor pulmonale may also contribute to the decreased cardiac output and hence to the systemic hypotension. A general discussion of the current armamentarium in the management of these cases has been presented.

The Pathogenesis of Amniotic-Fluid Embolism

IN 1941 Steiner and Lushbaugh1 described the syndrome of amniotic-fluid embolism, which they believed to be the major cause of death during labor. The clinical picture that they observed in 8 patie...

The role of the fetus and placenta in maintenance of plasma progesterone

Abstract Within 2 hours after delivery of the placenta only minute amounts of progesterone could be demonstrated in the peripheral blood. After delivery the progesterone content of the uterine vein blood fell sharply. The greatest concentration of progesterone was found in a single sample from the intervillous pool and umbilical vein blood. The variation of progesterone during the day suggests that there may be a diurnal rhythm. The higher values at 6 a.m. on the first day of admission may indicate that progesterone levels in pregnant patients may be influenced by psychological factors. Clomiphene produced a consistent rise of progesterone in a 10 week pregnancy but not in one of 20 weeks, which suggests that it may stimulate the production of progesterone by the corpus luteum but not by the placenta.

Histology of the uterus and ovaries after long-term cyclic norethynodrel therapy

The histologic findings in the ovaries and uteri of 27 women who had taken Enovid for up to 2 years are presented. Cervices showed hypersecretion in the endocervical glands consistently in patients who had taken the drug for more than 6 cycles. Endometrial changes included : 1) sparse straight glands throughout the cycle 2) secretory activity beginning about Day 9 and exhausted by Day 20 3) mild edema between Days 8 and 17 and 4) extreme thinness. Ovaries were generally inactive; inactive cystic and atretic follicles were present in most cases and no corpora lutea were found. 3 instances of pelvic thrombi were found. In a small number of women studied after cessation of therapy ovulation was frequently delayed 10 days to 2 weeks beyond the usual 14-day point. Discussion includes the findings of pelvic thrombi and the possible relation of Enovid therapy to fatal pulmonary embolism.

The incompetent cervix in repetitive abortion and premature labor.

IN obstetric practice, it is acknowledged that a significant number of patients, without apparent cause, repeatedly terminate their pregnancies between the early part of the middle trimester and th...

Observations on the fetal aspects of placental circulation

Abstract 1. 1. The fetal vascular ramifications of the human placenta have been studied with a variety of injection techniques. Vinyl acetate injected placentas have been corroded. India ink-injected material has been cleared with a modified Spalteholtz procedure. 2. 2. The intimate nature of the relationships of maternal and fetal vascular channels within the placenta has been a major source of difficulty in study of the uteroplacental circulation. 3. 3. The fetal capillary network though extensive has been found to be short in linear magnitude. This morphologic feature may be basic in the mechanism of adequate venous return. No beadlike medium or large-sized veins have been identified. 4. 4. Spiraled fetal main stem vessels of the placenta, by analogy, may reflect a response of trophic stimulation of steroid hormones, previously suggested for the ovary, myometrium, and endometrium. It allows for a gradient of pressure to the capillary bed. 5. 5. The capillary network of the subchorionic zone is sinusoidal in nature. The area adjacent to the decidual plate, in contrast, has a plexiform arrangement. This morphologic discrepancy suggests diverse functional activity in the various zones of the placenta.

The electroencephalogram in pregnancy

Abstract This study was planned as a preliminary survey of the electroencephalogram in pregnancy with the special purpose of determining whether the electrical activity of the cortex is modified in normal pregnancy and whether there is a difference between the electrical activity of the cortex in normal pregnancy and in pregnancy complicated by toxemia.