Vern L. Katz

Meconium aspiration syndrome: Reflections on a murky subject

Meconium-stained amniotic fluid occurs in approximately 12% of live births. In approximately one third of these infants meconium is present below the vocal cords. However, meconium aspiration syndrome develops in only 2 of every 1000 live-born infants. Ninety-five percent of infants with inhaled meconium clear the lungs spontaneously. Recent investigations have suggested that a reexamination of our assumptions about the etiology of meconium aspiration syndrome is in order. Several authors have provided evidence that support the hypothesis that it is not the inhaled meconium which produces the primary pathologic condition of meconium aspiration syndrome but rather it is fetal asphyxia that is the etiologic agent. Asphyxia in utero produces pulmonary vasospasm and hyperreactivity of the pulmonary vessels. With severe asphyxia the fetal lungs undergo pulmonary vascular damage with pulmonary hypertension. The damaged lungs are then unable to clear the meconium. In the most severe cases there is right-to-left shunting and persistent fetal circulation with subsequent fetal death. The incidence of meconium aspiration may thus be essentially unaffected by current obstetric and pediatric interventions at birth. For the asphyxiated or distressed infant we recommend suctioning at birth and tracheal intubation. In the healthy fetus observation may be sufficient.

Maternal and fetal outcomes in hyperemesis gravidarum

Objective: This study sought to evaluate maternal characteristics and pregnancy outcomes among women with hyperemesis gravidarum. Methods: We performed a retrospective analysis of pregnancy records of obstetric admissions during a 6‐year period. Women treated as out‐patients for hyperemesis were also identified. Hyperemesis was defined as excessive nausea and vomiting resulting in dehydration, extensive medical therapy, and/or hospital admission. Statistical analysis was by t‐test and chi square. Results: We identified 193 women (1.5%) who developed hyperemesis among 13053 women. Racial status, marital status, age, and gravidity were similar between the hyperemesis patients and the general population. However, there were less women with hyperemesis who were para 3 or greater. Forty‐six women (24%) required hospitalization for hyperemesis, mean hospital stay 1.8 days, range 1–10 days. One patient required parenteral nutrition, two had yeast esophagitis, none had HIV infection, psychiatric pathology or thyroid disease. Pregnancy outcomes between hyperemesis patients and the general population were similar for mean birth weight, mean gestational age, deliveries less than 37 weeks, Apgar scores, perinatal mortality or incidence of fetal anomalies. Our incidence of hyperemesis (1.5%) is similar to that of other published reports. Conclusion: Women with hyperemesis have similar demographic characteristics to the general obstetric population, and have similar obstetric outcomes.

Increased incidence of sepsis at birth in neutropenic infants of mothers with preeclampsia

Neutropenia is often found at birth in infants born to mothers with preeclampsia, and is most likely present in utero. To determine whether this neutropenia is associated with an increased incidence of early-onset sepsis, we reviewed the hospital records of 301 low birth weight infants of mothers with preeclampsia. Early-onset sepsis was proved if the result of a culture of blood or cerebrospinal fluid in the first 48 hours of life was positive, or presumed if culture results were negative but two or more clinical signs of sepsis were present and the attending neonatologist believed that an infant was infected and needed at least 7 days of antibiotic therapy. Forty-eight percent of low birth weight infants of mothers with preeclampsia had neutropenia at less than 12 hours of age. Infants with neutropenia had mothers with more severe preeclampsia, were more premature (30 weeks vs 32 weeks), weighed less (1097 gm vs 1615 gm), and were more likely to be small for gestational age. Although maternal and obstetric risk factors for infection were less common in the group with neutropenia, rates of proven or presumed early-onset sepsis were higher (14% vs 2%; p < 0.001). Sepsis was proved in 6% of infants with neutropenia and in none of the infants without neutropenia (p = 0.03). A logistic regression analysis of the relative effects of birth weight, gestational age, and absolute neutrophil count on the incidence of sepsis revealed that only a low absolute neutrophil count correlated significantly with an increased risk of early-onset sepsis in infants with neutropenia.

The Society for Obstetric Anesthesia and Perinatology Consensus Statement on the Management of Cardiac Arrest in Pregnancy

This consensus statement was commissioned in 2012 by the Board of Directors of the Society for Obstetric Anesthesia and Perinatology to improve maternal resuscitation by providing health care providers critical information (including point-of-care checklists) and operational strategies relevant to maternal cardiac arrest. The recommendations in this statement were designed to address the challenges of an actual event by emphasizing health care provider education, behavioral/communication strategies, latent systems errors, and periodic testing of performance. This statement also expands on, interprets, and discusses controversial aspects of material covered in the American Heart Association 2010 guidelines.

Unexplained Elevations of Maternal Serum Alpha-fetoprotein

Alpha-fetoprotein (AFP) is a commonly used prenatal screening test for congenital anomalies. However, when anomalies are excluded after high resolution ultrasound and/or amniocentesis, an elevated maternal serum AFP (MSAFP) has been found to be associated with a 2- to 4-fold increase in low birthweight resulting from both preterm delivery and intrauterine growth retardation. Unexplained MSAFP elevations are also associated with up to 10-fold increase of placental abruption and a 10-fold increase in perinatal mortality. Results from studies of over 225,000 screened pregnancies indicate that 20 and 38 per cent of women with an unexplained MSAFP elevation may have an adverse pregnancy outcome. Twin gestations with MSAFP elevations greater than four multiples of the median are associated with similar constellations of pregnancy complications. Maternal serum AFP elevations in women with pregnancy complications are most likely the result of a leak of AFP across the placenta. Optimum management of women with unexplained elevations has not yet been established; however, evaluation of fetal growth throughout gestation is important in these patients.

Cardiac Arrest in Pregnancy: A Scientific Statement From the American Heart Association.

This is the first scientific statement from the American Heart Association on maternal resuscitation. This document will provide readers with up-to-date and comprehensive information, guidelines, and recommendations for all aspects of maternal resuscitation. Maternal resuscitation is an acute event that involves many subspecialties and allied health providers; this document will be relevant to all healthcare providers who are involved in resuscitation and specifically maternal resuscitation.

The effect of pregnancy on metabolic responses during rest, immersion, and aerobic exercise in the water

To examine the effects of advancing pregnancy on metabolic responses, 12 women, who were recruited early in pregnancy, were studied during 20 minutes of immersion in 30 degrees C water, followed by 20 minutes of exercise in the water (60% of predicted maximal capacity) and 20 minutes of lateral supine recovery. Each subject completed the trials during the fifteenth, twenty-fifth, and thirty-fifth weeks of pregnancy, as well as a control period 8 to 10 weeks post partum. Resting oxygen uptake increased with advancing pregnancy. Resting oxygen uptake was higher in the water than on land but was not altered by pregnancy. Exercise oxygen uptakes were similar for all trials, but the work load required to elicit the VO2 decreased during the thirty-fifth week of pregnancy. Exercise heart rates followed the same pattern as oxygen uptake. Lactate concentrations declined with advancing pregnancy after exercise. Blood glucose levels were normal for pregnancy but declined slightly during exercise. Blood triglyceride levels were elevated with exercise, with a tendency to increase with advancing pregnancy. Resting plasma cortisol concentrations increased with pregnancy but remained lower during immersion and exercise. These results suggest that pregnancy significantly alters metabolic responses to exercise in the water.

Nifedipine and its indications in obstetrics and gynecology

Objective: To review studies and investigations regarding the safety and efficacy of nifedipine. Data sources and methods: We reviewed the published literature on calcium channel blockers and their pharmacology and therapeutic applications in obstetrics and gynecology. We paid particular attention to methods of animal research and recent clinical evaluations. Conclusions: The dihydropyridine group of calcium channel blockers (type II calcium blockers) and, specifically, nifedipine are safe for use in pregnancy. They have little teratogenic or fetotoxic potential. Nifedipines mechanism of action is through smooth‐muscle relaxation secondary to blockage of the slow calcium channels into the cells. In vivo, there is minimal effect on the cardiac conducting system. Multiple studies in women have demonstrated the effectiveness and safety of nifedipine as an antihypertensive. Therapeutic doses range from 10‐30 mg orally every 6‐8 hours. For acute control of hypertension, 10 mg of sublingual nifedipine may be used. Nifedipine is as effective as betamimetics in decreasing uterine activity. As a tocolytic agent, it is more effective as there are fewer patients who have to discontinue nifedipine because of side effects. The side effects of nifedipine include flushing, headache, or, rarely, hypotension in the hypovolemic patient. Nifedipine has potential and theoretical indications for dysmenorrhea and bladder irritability. (Obstet Gynecol 1994;83:616‐24)

Necrotizing fasciitis of the vulva

OBJECTIVE We attempted to characterize the natural history of necrotizing fasciitis of the vulva. STUDY DESIGN The records of 29 nonpregnant women with necrotizing fasciitis of the vulva were evaluated. RESULTS These women experienced a rapidly progressing polymicrobial infection. Initially, the infections in many women were thought to be labial cellulitis, appearing mild and innocuous. Delays in recognition and aggressive surgical management were associated with increased morbidity and mortality. Of 15 women with a delay greater than 48 hours between presentation and treatment, 11 died. Twenty of 29 (69%) were diabetic, accounting for 11 of the 14 deaths. CONCLUSION Early diagnosis and aggressive surgical debridement in spite of mild symptoms will improve outcome in this serious disease process.

Perimortem cesarean delivery: its role in maternal mortality.

Since Roman times, physicians have been instructed to perform postmortem cesarean deliveries to aid in funeral rites, baptism, and in the very slim chance that a live fetus might still be within the deceased mothers womb. This procedure was disliked by physicians being called to a dying mothers bedside. As births moved to hospitals, and modern obstetrics evolved, the causes of maternal death changed from sepsis, hemorrhage, and dehydration to a greater incidence of sudden cardiac arrest from medication errors or embolism. Thus, the likelihood of delivering a viable neonate at the time of a mothers death increased. Additionally, as cardiopulmonary resuscitation (CPR) became widespread, physicians realized that during pregnancy, with the term gravid woman lying on her back, chest compressions cannot deliver sufficient cardiac output to accomplish resuscitation. Paradoxically, after a postmortem cesarean delivery is performed, effective CPR was seen to occur. Mothers were revived. Thus, the procedure was renamed the perimortem cesarean. Because brain damage begins at 5 minutes of anoxia, the procedure should be initiated at 4 minutes (the 4-minute rule) to deliver the healthiest fetus. If a mother has a resuscitatable cause of death, then her life may be saved as well by a prompt and timely cesarean delivery during CPR. Sadly, too often, we are paralyzed by the horror of the maternal cardiac arrest, and instinctively, we try CPR for too long before turning to the perimortem delivery. The quick procedure though may actually improve the situation for the mother, and certainly will save the child.