Evaluation of a perinatal autopsy protocol: influence of the Prenatal Diagnosis Conference Team.

This study was designed to evaluate changes in the perinatal autopsy following the adoption of a new autopsy protocol. The University of Utah Medical Center has a Prenatal Diagnosis Conference Team composed of obstetricians, pediatricians, geneticists, and other health care professionals. These individuals are involved in the care of patients whose pregnancies are at risk for congenital malformations. An autopsy protocol was designed to increase the interaction of the pathologist with the Prenatal Diagnosis Conference Team in the evaluation of perinatal death. Two years, 1982 and 1987, before and after the protocol was implemented, were selected for retrospective review. The autopsies in 1987 made more specific diagnoses compared with those in 1982. Additional congenital anomalies were diagnosed, and increased numbers of patients were found to have well-described congenital disorders. The number of attempted postnatal autopsy chromosome studies increased and more chromosomal abnormalities were detected. The final autopsy diagnoses made in 1987 have provided more information to the physician for genetic or other patient counseling. After the protocol was adopted, increased numbers of cases were referred to the Medical Center for evaluation at autopsy. More of those who came to autopsy had been evaluated during life by members of the Prenatal Diagnosis Conference Team. Premortem sonograms had been done at an earlier gestational age and a greater number of anomalies were detected. Fewer of the fetuses had intrauterine death and more had pregnancy terminated by induction of labor. The gestational age at delivery declined.

Phenytoin metabolism in pregnancy.

Approximately 45% of patients with epilepsy experience an increase in seizure frequency during pregnancy. Despite the availability of effective anticonvulsant medications, there has been no decrease in reported seizure frequency accompanying pregnancy in the past 35 years. The authors prospectively studied concentrations of phenytoin (DPH) and its metabolites in 5 patients throughout pregnancy and during the postpartum period. The concentrations of phenytoin, as well as both unconjugated and conjugated forms of its principal metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin (4-OH-DPH), were measured in plasma and urine by a precise high-pressure liquid chromatography method. Four patients experienced a decrease in plasma DPH during gestation, 3 of whom developed seizures at a time of low plasma DPH concentration. Within the therapeutic range, small increments in dosage resulted in large increments in plasma DPH levels, and in the postpartum period high levels of DPH were encountered if the dosage was not reduced. As pregnancy progressed, there was a decrease in the percentage of the daily dosage of DPH excreted as 4-OH-DPH. Based on these observations, the authors conclude that 1) pregnancy is associated with altered DPH absorption or metabolism or both, and 2) periodic measurement of plasma DPH concentration is valuable when managing a pregnant epileptic patient.

Normal values for amniotic fluid index during uncomplicated twin pregnancy.

OBJECTIVE: To establish the gestational age trends of amniotic fluid index (AFI) in uncomplicated twin pregnancies. METHODS: Amniotic fluid index was measured in uncomplicated twin pregnancies seen between 1985 and 1993 and meeting the following criteria: 1) no maternal medical or obstetric complications, 2) normal growth of both twins by serial ultrasound, and 3) normal amniotic fluid volume by ultrasound. Amniotic fluid index was measured by adding the deepest vertical pockets in four quadrants, defined by the umbilicus and linea nigra. The relation between gestational age and AFI was evaluated using linear regression analysis. RESULTS: Two hundred eighty-two sets of twins were considered uncomplicated; 1101 AFI measurements were performed on these pregnancies between 25.5 and 40.5 weeks' gestation. Percentile values for AFI were determined according to gestational age. The regression equation relating the median AFI to gestational age was: AFI = 19.4 - 0.12 x gestational age (P = .03). The R2 value was 0.04. CONCLUSION: Gestational age trends in normative AFI measurements for twin pregnancies have been established. Their use will facilitate a more reproducible, quantitative diagnosis of oligohydramnios in twins, compared with subjective, qualitative approaches to amniotic fluid volume assessment.

Ultrasound air contrast transfusion technique: an aid to managing the Rh-affected fetus with ascites.

The successful management of an Rh-sensitized pregnant patient is reported in whom fetal intrauterine transfusions were utilized despite the presence of fetal ascites before the 26th week of gestation. A new ultrasound air contrast technique is described that confirms the correct intraabdominal placement of the transfused blood. The technique is not dependent on the amount of blood introduced, nor is it masked by fetal ascites.

Effect of pregnancy on diabetic retinopathy.

The incidence of progression of diabetic retinopathy during pregnancy is unknown and its proper management uncertain. In this study, 55 insulin-dependent diabetic patients under strict glucose control were followed throughout pregnancy with serial retinal examinations by ophthalmoscopy and photographs. Nineteen patients had minimal or background retinopathy and 7 had untreated proliferative changes. Six patients had been treated before pregnancy with photocoagulation for proliferative retinopathy. A positive correlation was found between progressive proliferative diabetic retinopathy and the duration of diabetes mellitus independent of glucose control. During gestation 3 of 19 patients (16%) with minimal or background retinopathy and 6 of 7 patients (86%) with untreated proliferative retinopathy experienced deterioration of their eye disease. In 4 patients with proliferative retinopathy, progression of retinal disease was arrested with photocoagulation during pregnancy. Only 1 of 6 who had received laser treatment prior to pregnancy experienced progression of her retinopathy. These results suggest that photocoagulation prior to pregnancy may protect against rapidly progressive proliferative retinopathy and that aggressive treatment during pregnancy can prevent progression of proliferative retinopathy and visual impairment.

Antepartum diagnosis and intrapartum management of lethal renal defects.

Bilateral renal agenesis (Potter syndrome) in the neonate is incompatible with life. Unfortunately, these infants are often delivered by cesarean section, as premature labor and breech presentation are commonly associated with the condition. In reviewing the obstetric course of 6 women who recently delivered such babies, the authors have found that antepartum diagnosis is possible in most cases. specifically, vaginal delivery should be strongly considered for patients in premature labor with intact membranes and breech presentation when there is ultrasound evidence of an abnormally shaped fetal head, absence of the fetal bladder, and severe oligohydramnios.

A new postpartum syndrome associated with antiphospholipid antibodies.

Three women with antiphospholipid antibodies and a postpartum syndrome of pleuropulmonary disease, fever, and cardiac manifestations are presented. Each patient had either lupus anticoagulant or anticardiolipin antibodies or both, but did not have antinuclear antibodies or fulfill the criteria for the diagnosis of systemic lupus erythematosus. No infection or embolus was detected that could explain the pulmonary findings. All three patients had electrocardiographic abnormalities, and one patient developed a cardiomyopathy with extensive immunoglobulin G (IgG), IgM, IgA, and C3 deposition in the myocardium. In addition to the reported association between antiphospholipid antibodies and fetal loss, fetal growth retardation, and preeclampsia, we suggest that patients with antiphospholipid antibodies are at risk for a previously unreported and serious autoimmune postpartum syndrome.

Maternal-fetal pH difference and fetal scalp pH as predictors of neonatal outcome.

The purpose of this study was to determine if interpretation of fetal scalp pH values would be enhanced by concurrent measurement of maternal venous pH. The last fetal capillary pH obtained before delivery was compared with simultaneous maternal-fetal pH difference as predictors of neonatal outcome assessed by five-minute Apgar scores. Fetal scalp pH and maternal-fetal pH difference were significantly correlated with r = -0.72 (P less than .0001). The acidotic fetuses born to acidotic mothers had low maternal-fetal pH differences, and all were nondepressed at birth. A 33% reduction in false negatives was found using maternal-fetal pH difference instead of scalp pH alone. Errors in interpretation of fetal scalp pH can be reduced by the use of maternal-fetal pH difference.

Intrapartum fetomaternal bleeding in Rh-negative women.

In a series of 1206 consecutive Rh-negative women who delivered Rh-positive infants, fetal erythrocytes were found in the maternal blood of 175 (14.5%) during the postpartum period. In 12 (1.0%) there was evidence of a larger fetomaternal hamorrhage than would be neutralized by a single 300-microgram dose of Rh-immune globulin. Except for manual removal of the placenta, no correlation was found between large fetomaternal hemorrhages and obstetric manipulations, complications, or surgery. Thus, the authors believe that all Rh-negative patients should be screened post partum to ascertain the adequacy of Rh-immune globulin prophylaxis.

Intrapartum obstetric emergencies.

Shoulder dystocia, uterine inversion, and prolapse of the umbilical cord are three uncommon complications of the intrapartum period. These complications share several common characteristics in that they are rare, difficult to predict, and can result in significant morbidity and mortality. This article describes the etiology, predisposing factors, and methods of management of these complications.

Intrapartum management of twin gestation.

The intrapartum management of the patient with a multiple gestation should begin in the antenatal period. With the present widespread use of ultrasound, the number of multiple gestations diagnosed early in pregnancy has now increased, permitting determination of placentation and monitoring of fetal growth. When a patient with a twin gestation presents in labor, ultrasound should be used to establish fetal presentation and size. The fetal well-being should be evaluated with fetal heart monitoring, and assessment of potential maternal complications, such as anemia, hypertension, and polyhydramnios, should be accomplished. With more than two fetuses, cesarean delivery is recommended. The principal controversy in intrapartum management of twin gestation relates to the planned route of delivery, particularly because this consideration is influenced by malpresentation and prematurity. There is general agreement favoring vaginal delivery for vertex-vertex twin pairs. With dual fetal heart rate monitoring and appropriate delivery room preparation for emergency cesarean section, recent evidence supports planned vaginal delivery of the mature nonvertex second twin. Elective cesarean section for the nonvertex second twin estimated as weighing less than 1800 gm is advised.

Doppler velocimetry in pregnancy.

Since the late 1970s, Doppler velocimetry has been investigated extensively for use in obstetrics. Initially, this technique showed promise for the management of certain complications of pregnancy; this promise has yet to be fulfilled. Doppler velocimetry of either the uterine or umbilical vessels, which showed some merit in selecting growth-retarded fetuses at particular risk, has neither become a screening tool for intrauterine growth retardation nor proven clinically successful in improving fetal outcome. Likewise, its use for other complications of pregnancy (eg, postdate pregnancy, twin pregnancy, and diabetes) has not led to improved pregnancy outcome. More recently this technique has been used to study other vascular beds. Changes in the Doppler characteristics of these vascular beds may demonstrate the fetal response to its environment. These investigations provide the potential for a better understanding of fetal physiology; however, it has yet to be shown by prospective evaluation that their application results in improved pregnancy outcome. This review defines the uses and limitations of Doppler ultrasound in current obstetric practice.

Irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy.

Constrictive pericarditis is a rare but potentially life-threatening complication of pregnancy. This is a case report of irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy. It is hoped that our team approach to this particular problem can serve as a model for the management of similar medical and surgical complications of pregnancy.

Consequences of fetomaternal haemorrhage after intrauterine transfusion.

Fetomaternal haemorrhage was studied after 68 consecutive fetal intravascular transfusions performed in 20 patients with Rh isoimmunisation. alpha Fetoprotein concentration was assayed in maternal blood taken before, and immediately after each transfusion and three and 24 hours later. An increase of 50% or more in the concentration in any of the samples after transfusion was considered to indicate fetomaternal haemorrhage. Fetal alpha fetoprotein concentration in blood sampled before transfusion was also assayed and the amount of fetomaternal haemorrhage calculated. Fetomaternal haemorrhage occurred in 21 of 32 patients with an anterior placenta and in six of 36 with a posterior or fundal placenta. The mean estimated volume of haemorrhage was 2.4 ml, which was on average equal to 3.1% of the total fetoplacental blood volume. When the volume of fetomaternal haemorrhage at the first transfusion was greater than 1 ml there was a greater increase in maternal Rh (D) antibody titres and a greater fall in fetal packed cell volume. Sampling of fetal blood should not be routinely done early in patients with Rh isoimmunisation, and intrauterine transfusion should be delayed as long as possible. Sampling sites other than the placental cord insertion reduces the risk of fetomaternal haemorrhage.

Adverse pregnancy outcome: sensitive periods, types of adverse outcomes, and relationships with critical exposure periods.

A wide variety of agents has been demonstrated to be capable of affecting the fetus in utero. Certain generalizations can be made concerning these teratogens. Two of the most important of these principles are the specificity of the agent and the time during gestation of the exposure. Although noticeable adverse effects are structural malformations, there are numerous functional malformations, such as lower intelligence and poor reproductive outcome, that may follow exposure to these agents. There is some evidence that future behavior may be affected by in utero teratogen exposure; however, this field has been infrequently investigated and no firm conclusions can be drawn.

Lactation suppression.

In spite of a very recent upsurge in breast-feeding in industrialized countries, approximately one-half of parturients are candidates for postpartum lactation suppression. The mechanisms controlling lactation are complex and involve preparation of the breast during pregnancy, stimulation of secretion of milk in the immediate postpartum period, ejection of milk from the alveolar cells, and maintenance of milk production during the period od lactation. The local effects of estrogen and progesterone in the breast prevent milk secretion during pregnancy. With their withdrawal in the postpartum period, the stimulating effect of the anterior pituitary hormone prolactin dominates and milk secretion is initiated and maintained. Milk ejection is accomplished by a neurohormonal reflex resulting in stimulation of the myoepithelial cells of the breast by the posterior pituitary hormone oxytocin. Local stimulation of the breast by suckling is important in initiating the release of oxytocin and also the secretion of prolactin. The suppression of lactation in the postpartum period can be accomplished in approximately 60--70% of females by the use of a tight brassiere and avoidance of stimulation of the nipples. An additional 10% or so of females can be helped with the use of estrogens during the postpartum period. The addition of an androgen to the estrogen increases the success rate of lactation suppression to about 90%. Unfortunately, the use of estrogen alone or in combination with an androgen is accompanied by rebound lactation in a significant number of patients and has been associated with an increased incidence of postpartum thromboembolic disease. Lactation suppression by inhibiting prolactin secretion with synthetic ergot alkaloids such as bromocriptine has been shown to be safe and highly effective both immediately post partum and after lactation has been established. The 2 week period of therapy required with this drug may be unsatisfactory for some patients. If given immediately at delivery, a single injection of testosterone enanthate and estradiol valerate is equally effective in suppressing lactation and, in the young patient who has delivered vaginally, is not associated with significant risk.

PIP: Newer aspects of the physiology of lactation are reviewed, and methods currently available to the clinician for its suppression are examined. Despite a recent increase in breastfeeding in industrialized nations, about 1/2 of parturients are candidates for postpartum suppression. Mechanisms controlling lactation are complex, and they involve preparation of the breast during pregnancy, stimulation of secretion of milk in the immediate postpartum period, ejection of milk from the alveolar cells, and maintenance of milk production during the period of lactation. The local effects of estrogen and progesterone in the breast prevent the secretion of milk during pregnancy. With their withdrawal during the postpartum period, the stimulating effect of the anterior pituitary hormone prolactin dominates and milk secretion is initated as well as maintained. A neurohormonal reflex resulting in stimulation of the myoepithelial cells of the breast by the posterior pituitary hormone oxytocin is responsible for milk ejection. Local stimulation of the breast by suckling is important in initiating the release of oxytocin as well as the secretion of prolactin. The use of a tight brassiere and avoidance of stimulation of the nipples can accomplish the suppression of lactation in the postpartum period in about 60-70% of females. Another 10% or so can be helped with the use of estrogens during the postpartum period. The addition of an androgen to the estrogen increases the success rate of lactation suppression to approximately 90%. The use of estrogen alone or in combination with androgen is accompanied by rebound lactation in a significant number of women and has been associated with an increased incidence of postpartum thromboembolic disease. Lactation suppression by inhibiting prolactin secretion with synthetic ergot alkaloids has been shown to be safe and highly effective.

Other causes of fetal death.

Although perinatal mortality rates have fallen considerably in the past several decades, the fetal component of this statistic has not decreased as rapidly as the neonatal portion. Syphilis, a significant cause of fetal death at the beginning of this century, has been eliminated and other conditions such as erythroblastosis fetalis and diabetes mellitus have been markedly reduced. It is clear, however, that minimum fetal mortality has not been achieved. Potentially salvagable fetuses still die from the effects of maternal hypertension, intrauterine growth retardation, and post-maturity. Widespread application of current knowledge and techniques would save some of these fetuses; others will only be saved with an increased understanding of pathological processes and their treatment. In the meantime, it is imperative that those involved in obstetrical care follow the sound principles of accurate determination of gestation age, identification of patients at risk for fetal death, meticulous care of associated medical conditions, and careful attention to the progress of pregnancy.