Characteristics of neonatal intensive care unit patients in North Carolina: a cross-sectional survey

A shortage of neonatal intensive care facilities has been encountered in some areas of the country including North Carolina. To examine possible solutions to this health care delivery problem, a cross-sectional survey of all the neonatal intensive care units in North Carolina was performed to examine characteristics of patients occupying the beds in these facilities. It was found that a substantial amount of chronic care is now occurring in neonatal intensive care beds, with 38% of occupants of neonatal intensive care beds being 31 days of age or older and 3% being mechanically ventilated at 91 days of age or older. In addition, according to criteria established for this study, a substantial number of "convalescent" patients (32%) were occupying beds in neonatal intensive care units. It is concluded that an increase in both intermediate/convalescent care beds and establishment of chronic care facilities in North Carolina, rather than an increase in intensive care beds in these units, would alleviate the shortage of neonatal intensive care facilities. Further, the characteristics of the population occupying neonatal intensive care unit beds should be considered by health planners in addition to occupancy rate, when new facilities are being established.

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.

The thermoregulation of pregnant women during aerobic exercise in the water: a longitudinal approach

Twelve women early in their pregnancies were recruited to examine thermoregulation during immersion and exercise in the water (30 degrees C). Their responses were compared at 15, 25 and 35 weeks of pregnancy as well as 10-12 weeks post pregnancy to determine whether the responses differ between the gravid and non-gravid woman or were modified during pregnancy. Rectal temperature, mean skin temperature, heat storage, and evaporation were similar during immersion or exercise during the 15th, 25th and 35th weeks of pregnancy. Compared to 10 weeks post partum, pregnancy reduced heat storage, lowered skin temperature and increased evaporative heat loss during immersion and exercise (P less than 0.05). The results suggest that pregnancy causes subtle changes in the mechanism of thermoregulation which tend to increase heat production and improve heat conservation.

Nifedipine enhances the cardiac toxicity of magnesium sulfate in the isolated perfused Sprague-Dawley rat heart

Magnesium sulfate is commonly used in tocolytic regimens and as prophylaxis against seizures. Nifedipine may be used simultaneously in either situation. With the isolated perfused rat heart model (Sprague-Dawley rats), we investigated the effects of these agents on cardiac function. Whereas each agent alone depressed cardiac performance, the two drugs together had maximal depressive effects on the heart.

Terms of confinement

Through habit we have chosen words to describe antepartum, intrapartum, and postpartum events that are domineering and restricting and that are consistent with imprisonment. We must be cognizant of the potential impact of our language.

Nonweightbearing exercise during pregnancy on land and during immersion: a comparative study

Seven women at 25 weeks' gestation exercised on land and in the water at 70% maximum oxygen capacity (VO2max) on a bicycle ergometer. Women had significantly lower heart rates and lower systolic blood pressures during immersion exercise. Women had a mean diuresis of 207 ml (6.5 ml/min) during water exercise compared with 98 ml. (2.4 ml/min) during land exercise. Fetal heart rates showed a tendency toward being higher after land exercise compared with water exercise. Six of seven fetuses displayed tachycardia after land exercise compared to one of seven after water exercise. Exercise on land and during immersion at 70% VO2max was well tolerated. However, exercise during immersion offers several physiologic advantages during pregnancy.

Magnesium sulfate tocolysis in selected patients with symptomatic placenta previa

Tocolysis can be used to arrest contractions in selected patients with placenta previa if the maternal condition is stable. Over a 5-year period, 41 patients with symptomatic placenta previa were treated, of whom 18 were given magnesium sulfate therapy for tocolysis. The mean prolongation of gestation was 18.5 days, and tocolysis was successful in 17 of 18 cases. Since betamimetic drugs used for tocolysis may mask or blunt maternal cardiovascular responses to volume depletion, magnesium sulfate is a better choice to inhibit contractions in patients with symptomatic placenta previa whose bleeding is mild or moderate.

Renal responses to immersion and exercise in pregnancy

Twelve healthy pregnant women were studied at 15, 25, and 35 weeks' gestation and at 8 to 12 weeks postpartum. Women were immersed for 20 minutes at 30 degrees C. They then exercised at 60% maximum oxygen capacity on a modified ergometer. Substantial diuresis and natriuresis occurred without changes in osmolarity or serum sodium. The diuresis was significantly greater during pregnancy than postpartum. The natriuresis was similar. Diuresis and natriuresis were greater than would be expected from investigations in nonpregnant subjects. This study suggests that immersion may be a beneficial therapy for edema without decreasing plasma volume.

Epidural analgesia and autonomic hyperreflexia: a case report

Autonomic hyperreflexia is a serious complication for paraplegic patients. A paraplegic woman in early labor presented with autonomic hyperreflexia. After epidural analgesia was established, hyperreflexia resolved. When the analgesic wore off, hyperreflexia returned. Continuous epidural analgesia may be helpful for pregnant women who are susceptible to autonomic hyperreflexia.

A comparison of bed rest and immersion for treating the edema of pregnancy

Bed rest and immersion both lead to a mobilization of extravascular fluid and thus reduce edema. This study compared three treatments for edema in healthy pregnant women in the third trimester: lateral supine bed rest at room temperature, sitting in a bathtub of waist-deep water at 32 +/- 0.5C with legs horizontal, and sitting immersed in shoulder-deep water at 32 +/- 0.5C with legs extended downward. Post-treatment diuresis was selected as the indicator of extravascular fluid mobilization. The mean (+/- SD) diuresis was 105 +/- 48, 161 +/- 155, or 242 +/- 161 mL/hour for bed rest, bathtub, and immersion tank, respectively (P less than .008, tank versus bed rest; P less than .05, tank versus bath). In all treatments, mean arterial pressure (MAP) declined from a baseline value of 88 +/- 9 to 77 +/- 10 mmHg 25 minutes into treatment and 77 +/- 11 mmHg at 50 minutes (both P less than .0001 compared with pre-treatment). Shoulder-deep immersion produced the greatest decline in MAP. Sodium clearance increased from 0.7 to 1.0 mEq/minute in all treatments (P less than .01). Serum sodium, potassium, creatinine, osmolarity, total protein, 6-keto prostaglandin F1 alpha, and plasma volume did not change significantly after the treatments. Serum prolactin declined significantly from 137.8 +/- 44 to 124 +/- 31 ng/mL after treatment; there was no difference among treatments. Immersion appears to be a safe and more rapid method than bed rest to mobilize extravascular fluid during pregnancy.

The effects of immersion and exercise on prolactin during pregnancy

Prolactin is an important hormone during pregnancy, affecting mother, fetus, and amniotic fluid volume. Immersion is known to affect prolactin levels significantly. To determine the effect of immersion and exercise on the prolactin response during pregnancy, we examined serum prolactin levels at 15, 25, and 35 weeks' gestation and 10 weeks post partum. Twelve women completed 20 min land rest, 20 min immersion in 30 degrees C water to the xiphoid, and 20 min exercise in the water at 60% VO2max. Resting prolactin levels were 1.91 +/- 0.32, 4.55 +/- 0.5, and 5.85 +/- 0.27 nmol.l-1 +/- standard error of the mean at 15, 25, and 35 weeks' gestation, respectively. Postpartum lactating women had a resting mean prolactin level of 3.95 +/- 1.6 versus 0.22 +/- 0.4 nmol.l-1 in non-lactating women. Prolactin levels declined significantly during immersion even after correction for dilution by plasma volume shifts. The immersion response was inversely related to the duration of pregnancy with 29%, 22%, and 12% drops during 15-, 25- and 35-week trials, respectively. Compared to rest, exercise prolactin levels remained depressed during the 15th and 25th week trials. We hypothesize that immersion in water caused prolactin levels to decline.

An epidemiologic study of contraception and preeclampsia

The primary hypothesis of this study was that contraceptive methods that prevent exposure to sperm and seminal fluid (condoms, diaphragms, spermicides, withdrawal) are associated with an increased risk of developing preeclampsia during the subsequent pregnancy. A case-control study was conducted comparing the contraceptive and reproductive histories of 110 primiparous women with preeclampsia with 115 pregnant women without preeclampsia, aged 15 to 35 years, who gave birth at North Carolina Memorial Hospital, Chapel Hill, between 1984 and 1987. Controls were frequency matched to cases by age, race, and distance from the hospital. Unconditional logistic regression analysis indicated a 2.37-fold (95% confidence interval, 1.01 to 5.58) increased risk of preeclampsia for users of contraceptives that prevent exposure to sperm. A dose-response gradient was observed, with increasing risk of preeclampsia for those with fewer episodes of sperm exposure. These results were supportive of the hypothesis that birth control methods that prevent sperm exposure may play a role in the etiology of preeclampsia.

The zygote: to be or not be a person

It is no longer possible to claim that the biological characteristics of the future adult are already determined at conception. After all, a zygote may develop into a hydatidiform mole rather than into a human being. The development of an individual human person is determined by genetically and non-genetically coded molecules within the embryo, together with the influence of the maternal environment. Consequently, it is an error to regard the zygote's chromosomal (and other) DNA as sufficient to determine the uniqueness of the future individual.

Pseudotumor cerebri and pregnancy

We reviewed 11 pregnancies complicated by pseudotumor cerebri over a 6-year period for an incidence of approximately 1 in 870 births. No pregnancy was adversely affected, but symptoms of pseudotumor increased in 9 of 11 pregnancies. All patients were managed medically, 9 of 11 with analgesics and diuretics. Two cases required steroid therapy.

Hypersensitivity to magnesium sulfate

Two patients who were labor and delivery nurses were treated with intravenous magnesium sulfate because of preterm labor. Both patients had a rapid and sudden onset of an urticarial eruption. The eruption cleared when magnesium sulfate was discontinued. The reactions did not affect the mothers or fetuses, but other therapies to stop labor were necessary.

Pregnancies among physicians. A historical cohort study

Sixty-seven pregnancies in practicing physicians were compared with 201 pregnancies in nonphysicians in a historical cohort study. All subjects were cared for and delivered by the same obstetricians. Physician and nonphysician pregnancies of similar socioeconomic status were matched for age, race and parity. After statistically controlling for alcohol and tobacco use and adequacy of prenatal care, physicians had a 1.86 (1.00, 3.46) relative risk of an adverse pregnancy outcome. Physicians were at a 4.0 (1.58, 10.1) and 2.33 (0.93, 5.8) times higher risk for preterm labor and delivery than were nonphysicians. Pregnancies in physicians were found to be similar to those in nonphysicians in the use of obstetric technology except for an increased number of ultrasound examinations among physicians. These results suggest that physicians are at increased risk for an adverse pregnancy outcome and should be considered and treated as a high-risk obstetric group.

Effects of terbutaline sulfate on fetal cardiac function

An isolated heart preparation was used to study the effects of terbutaline sulfate (Brethine) on fetal cardiac function. Pregnant guinea pigs received daily subcutaneous injections of terbutaline for 10 day, whereas a control group received placebo injections. Fetal guinea pig hearts were evaluated for cariodynamic and pathologic differences. Fetuses exposed to terbutaline demonstrated a higher mean heart rate (p less than 0.01), a higher mean heart weight (p less than 0.05), a higher mean heart weight/body weight ratio (p less than 0.01), and a trend toward higher left ventricular systolic pressure levels (p less than 0.1). These hemodynamic responses in fetuses exposed to terbutaline may result in increased functional demands that may predispose myocardial tissue to damage.

Maternal death from carotid artery thrombosis associated with the syndrome of hemolysis, elevated liver function, and low platelets

A case is presented of cerebral infarction secondary to carotid artery thrombosis in a patient with hemolysis, elevated liver function, and low platelets (HELLP) syndrome. The patient's rebound thrombocytosis may have contributed to a hypercoagulable state. Severe preeclamptic patients with HELLP syndrome who experience a reactive thrombocytosis may represent a subset of women who have postpartum thrombosis.

The use of fetal and anencephalic tissue for transplantation

Advances in transplantation have extended the life and relieved the suffering of thousands of individuals. The prospect of being able to use tissues from embryos, as well as from anencephalic newborns, offers the promise of further relief of suffering. However, these possibilities raise significant moral and public policy issues. The question arises of the extent to which those who disapprove of abortion may make use of tissues derived from abortion in order to treat serious diseases. This essay argues that, with proper safeguards, such tissue can be used without cooperating in abortion. That is, even those who oppose abortion can benefit from the use of tissue procured during abortion. Questions also arise regarding the probity of maintaining a pregnancy in order to produce an anencephalic newborn whose biological existence will be maintained so as better to secure organs once death is declared. It is argued that, since no harm can be done to a being that has neither a sense of self or the capacity to feel pain, and since women have a right to forego abortions, there is no legitimate ground for opposing women's seeking meaning in their pregnancy through maximizing the opportunity of others to use the organs of their anencephalic newborn once death has been declared. Finally, it is argued that, since the capacities for sentience, a minimal condition for personhood, are never realized by an anencephalic, the entity has never been alive as a person. Therefore, there should be no opposition in principle to aborting anencephalics nor, after proper declaration, to making their organs available as one would after whole-brain death, despite the continued functioning of the brain stem.

Cardiovascular responses of pregnant women during aerobic exercise in water: a longitudinal study

To determine the effects of pregnancy on the cardiovascular responses to immersion and exercise in water, 12 women completed 20 min of immersion and 20 min of bicycle ergometry at 60% predicted VO2max in 30 degrees C water during their 15th, 25th, and 35th week of pregnancy as well as 8-10 weeks post partum. Immersion lowered the resting heart rate approximately 8 bts/min (P less than 0.05). Exercise in water also resulted in a lower heart rate as compared with the same level of exercise on land (132 +/- 4 vs 149 +/- 6 bts/min; P less than 0.05). Both the rest and exercise heart rate responses were independent of duration of pregnancy or pregnancy status. Post partum exercise cardiac output averaged 9.9 +/- 0.4 l/min, significantly lower (P less than 0.05) than the 15th (12.7 +/- 0.5), 25th (14.7 +/- 0.5), or 35th week (15.1 +/- 0.7 l/min). Total peripheral resistance was greatest (P less than 0.05) post partum (657 +/- 29 dyn.s/cm5) compared with either the 15th (515 +/- 27), 25th (407 +/- 18), or 35th week (450 +/- 23). The results indicate that exercise in water lowers the heart rate compared with land exercise at the same metabolic rate. The combined effect of exercise, water, and pregnancy may elevate the cardiac output more than expected on land, but the same general pattern of exercise response will be evident throughout the duration of pregnancy. The results further suggest that water alters the heart rate and blood pressure responses such that land-derived exercise target heart rates should not be used to prescribe exercise intensity in water.

Immunoglobulin levels in fetal anatomic compartments

Immunoglobulins G, M, and A were found in varying concentrations in four different human fetal anatomic compartments of 17 fetuses in the absence of apparent infection. The highest levels were noted in the thoracic cavity.

Elevated maternal serum alpha-fetoprotein with oligohydramnios: ultrasound evaluation and outcome

Nineteen pregnancies evaluated for elevated maternal serum alpha-fetoprotein levels were found to have moderate to severe oligohydramnios. There were no survivors among six fetuses with ultrasound-diagnosed urinary tract anomalies. We followed 11 of the remaining 13 pregnancies with serial ultrasound examinations. When the second ultrasound examination demonstrated severely decreased amniotic fluid, the outcome was always poor (intrauterine death, perinatal death, or fetal deformations). Of the five cases in which the second ultrasound showed normal to moderately decreased fluid, there were four surviving infants. When no primary malformations are seen on the initial ultrasound examination, serial ultrasound evaluations of amniotic fluid volume help predict the pregnancy outcome.

Fetal and uterine responses to immersion and exercise

We evaluated the responses of the fetal-maternal unit to immersion and exercise in the water at 15, 25, and 35 weeks' gestation. As seen by underwater ultrasound, fetuses demonstrated body, limb, and breathing movements. Fetal heart rates (FHRs) were normal, and unchanged from those at rest, during maternal exercise in the water at 60% VO2 maximum. In 21 of 23 cases, post-exercise nonstress tests were reactive within ten minutes. There was no uterine activity seen at either 25 or 35 weeks' gestation. Maternal serum alpha-fetoprotein was unaffected at all gestational ages. Neither maternal temperature nor calculated plasma volume changed during exercise. This general lack of effect contrasts with results from other studies involving similar levels of exercise on land. We speculate that the plasma volume expansion with immersion contributes to the normal FHR responses seen in this study.

Determinants of fetal heart rate response to vibroacoustic stimulation in labor

To determine whether the fetal heart accelerates in response to a sound stimulus in labor, 40 women at various stages of labor were chosen at random to receive either a vibroacoustic stimulus or sham stimulus over the fetal head. Subsequent fetal heart rate (FHR) accelerations occurred to a significantly greater extent in study patients. One hundred thirty-two high- and low-risk patients were studied to determine correlations between the acceleration response and other maternal and fetal variables. There was a statistically significant negative correlation between the heart rate response to stimulation and three maternal variables: the degree of cervical dilation, the presence of ruptured membranes, and use of epidural anesthesia. The degree of fetal response did not correlate significantly with fetal distress at delivery or abnormal FHR tracings at the time of stimulation. Fewer than one-fifth of the fetuses manifested variable heart rate decelerations after the stimulation. In light of possible risks, the clinical use of the fetal acoustic stimulation test in labor should wait until its diagnostic value is better defined.

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.