Unequal Impact of COL1A1 and COL1A2 Variants on Dentinogenesis Imperfecta

Dentinogenesis imperfecta (DI) is the main orodental manifestation of osteogenesis imperfecta (OI) caused by COL1A1 or COL1A2 heterozygous pathogenic variants. Its prevalence varies according to the studied population. Here, we report the molecular analysis of 81 patients with OI followed at reference centers in Brazil and France presenting COL1A1 or COL1A2 variants. Patients were submitted to clinical and radiographic dental examinations to diagnose the presence of DI. In addition, a systematic literature search and a descriptive statistical analysis were performed to investigate OI/DI phenotype-genotype correlation in a worldwide sample. In our cohort, 50 patients had COL1A1 pathogenic variants, and 31 patients had COL1A2 variants. A total of 25 novel variants were identified. Overall, data from a total of 906 individuals with OI were assessed. Results show that DI was more frequent in severe and moderate OI cases. DI prevalence was also more often associated with COL1A2 (67.6%) than with COL1A1 variants (45.4%) because COL1A2 variants mainly lead to qualitative defects that predispose to DI more than quantitative defects. For the first time, 4 DI hotspots were identified. In addition, we showed that 1) glycine substitution by branched and charged amino acids in the α2(I) chain and 2) substitutions occurring in major ligand binding regions-MLRB2 in α1(I) and MLBR 3 in α2(I)-could significantly predict DI (P < 0.05). The accumulated variant data analysis in this study provides a further basis for increasing our comprehension to better predict the occurrence and severity of DI and appropriate OI patient management.

Pamidronate affects the mandibular cortex of children with osteogenesis imperfecta

We hypothesized that mandibular cortical width (MCW) is smaller in children with osteogenesis imperfecta (OI) than in healthy children and that pamidronate can improve the cortical mandibular thickness. The aim of this study was to assess changes in the MCW on dental panoramic radiographs (DPRs) of children with normal bone mineral density (BMD) and with OI. We also compared the MCW of children with different types of OI regarding the number of pamidronate cycles and age at the beginning of treatment. MCW measurements were retrospectively obtained from 197 DPRs of 66 children with OI types I, III, and IV who were in treatment with a comparable dosage of cyclical intravenous pamidronate between 2007 and 2013. The control group had 92 DPRs from normal BMD children. Factorial analysis of variance was used to compare MCW measurements among different age groups and between sexes and also to compare MCW measurements of children with different types of OI among different pamidronate cycles and age at the beginning of treatment. No significant differences in results were found between male and female subjects in both OI and healthy children, so they were evaluated altogether (P > 0.05). There was an increase of MCW values related to aging in all normal BMD and OI children but on a smaller scale in children with OI types I and III. Children with OI presented lower mean MCW values than did children with normal BMD at the beginning of treatment (P < 0.05). A linear model estimated the number of pamidronate cycles necessary to achieve mean MCW values equivalent to those of healthy children. The thinning of the mandibular cortex depended on the number of pamidronate cycles, the type of OI, and the age at the beginning of treatment. DPRs could thus provide a way to identify cyclic pamidronate treatment outcomes in patients with OI.

Gangliosides on intestinal microcirculation and animal survival during reperfusion

This study investigated the effect of gangliosides (Gang) on small bowel microcirculation and animal survival after normothermic intestinal ischemia-reperfusion injury. Five adult male EPM-1 Wistar rats in each of three groups received FK506 (0.2 mg/kg), Gang (3 mg/kg), or vehicle (at same volume) either 24 or 12 hours prior to the experiment. The animals were anesthetized intramuscularly with ketamine (60 mg/kg) and xylazine (10 mg/kg) and hydrated with 80 mL/kg of prewarmed saline solution delivered subcutaneously before the ischemic insult and 40 mL/kg at 1 hour after reperfusion. Under anesthesia, they underwent a laparotomy with clamping of the superior mesenteric artery (SMA) at its origin for 75 minutes. Microcirculation was evaluated with a laser Doppler flowmeter, 5 minutes before ischemia (baseline) and reperfusion (ischemia), and 20, 40, and 60 minutes after reperfusion. Animal survival was observed up to 24 hours. Small bowel flow measured before ischemia was considered to be the baseline level (100%). After SMA occlusion a significant reduction in microcirculatory tissue perfusion to about 8% was observed in all groups. At 20, 40, and 60 minutes of reperfusion treatment with Gang (77%, 81%, and 100%) or FK506 (70%, 85%, and 98%) promoted better recovery of the intestinal microcirculation when compared to the control group (45%, 72%, and 75%). Concerning animal survival there was no difference between groups (just one animal from each group, Gang and FK506, survived up to 24 hours). Based on our data we conclude that Gang and FK506 improve intestinal microcirculation in ischemia-reperfusion injury but do not change animal survival after severe ischemia.

Gangliosides in rat femoral injury: early effect on intimal hyperplasia

Previous studies demonstrated that some immunosuppressive agents inhibit arterial intimal hyperplasia. Our previous studies demonstrated that gangliosides (Gang) have an immunosuppressive effect on as well as an anti-inflammatory role in the wound-healing process. Therefore, we decided to examine the effect of Gang on intimal hyperplasia. Twenty Wistar isogenic rats received a transverse division of the anterior wall of the femoral artery, followed by suturing using mononylon 10-0 under surgical microscopy and were then divided into two groups: Gang group, 3 mg/kg per day of Gang, and control group, vehicle, intramuscularly from surgery to death (1 and 3 weeks, respectively). Concentric intimal hyperplasia was observed in arteries stained by hematoxylin-eosin in control and Gang groups. However, the media layer did not demonstrate any major alterations. After 3 weeks, the Gang group showed more intimal hyperplasia than the control group. Therefore, because intimal hyperplasia worsened in the presence of Gang after 3 weeks, further studies will be necessary to clarify its role in intimal proliferation.

Sequential use of Prepidil and extra-amniotic saline infusion for the induction of labor in nulliparous women with very low Bishop scores

OBJECTIVE

To evaluate the efficacy of sequential use of Prepidil (prostaglandin E2 gel) and extra-amniotic saline infusion for the induction of labor in nulliparous women with very low Bishop scores.

STUDY DESIGN

Nulliparous women with singleton gestations, intact membranes and a cervical Bishop score of < or = 2 who received Prepidil gel and extra-amniotic saline infusion sequentially for the induction of labor between July 1996 and July 1998 were studied.

RESULTS

Thirty-one women met the inclusion criteria. Indications for induction included post-dates (six of 31), pre-eclampsia (ten of 31), diabetes (three of 31), oligohydramnios (three of 31), intrauterine growth restriction (two of 31) and non-reactive non-stress test (NST) (seven of 31). The average time from onset of induction to delivery was 38.1 +/- 13.5 h. Vaginal delivery was achieved in 80.6%. Women requiring > 2 doses of Prepidil had a higher risk of delivering abdominally (OR = 3.5). Three of seven (42.9%) women with labor induced for non-reactive NST but only three of 24 (12.5%) with labor induced for other indications had a Cesarean section delivery (p < 0.001).

CONCLUSIONS

Nulliparous women with very unfavorable cervices can be counselled that they have an 80% chance of vaginal delivery using sequential Prepidil and extra-amniotic saline infusion as an induction method, with 90% delivering within the first 48 h.

Expectant management of severe preterm preeclampsia: is intrauterine growth restriction an indication for immediate delivery?

OBJECTIVE

Expectant management of severe preterm preeclampsia is gaining widespread acceptance in clinical practice. The objective of our study was 2-fold-to determine the frequency of fetal deterioration with expectant management of severe preterm preeclampsia and to evaluate whether the presence of intrauterine growth restriction on admission is associated with a shorter admission-to-delivery interval or more deliveries resulting from nonreassuring fetal status in comparison with pregnancies with preeclampsia but without intrauterine growth restriction.

STUDY DESIGN

This was an observational study of women with singleton pregnancies at <34 completed weeks' gestation who were admitted to the hospital with the diagnosis of severe preeclampsia and managed expectantly. Fetal status on admission, admission-to-delivery interval, indication for delivery, and neonatal outcome were examined.

RESULTS

Forty-seven women were studied during a 3-year period (1996-1999). Gestational age at admission was 29.8 +/- 2.6 weeks. The mean admission-to-delivery interval for the entire group was 6.0 +/- 5.1 days; in 42.5% delivery was for fetal indications. In comparison with the absence of intrauterine growth restriction, the presence of intrauterine growth restriction at admission resulted in a significantly shorter admission-to-delivery interval (3.1 +/- 2.1 vs 6.6 +/- 6.1 days; P <.05). Most fetuses with intrauterine growth restriction (85.7%) were delivered before 1 week. Although 57% of fetuses with intrauterine growth restriction were delivered for fetal indications, versus 39% of fetuses without intrauterine growth restriction, these rates were not found to be significantly different. Neonatal outcomes, as reflected by Apgar scores, number of admissions to and duration of stay in the neonatal intensive care unit, and neonatal mortality rates, were similar.

CONCLUSION

Pregnancies complicated by severe preterm preeclampsia and the presence of intrauterine growth restriction at admission may not benefit from expectant management beyond the 48 hours needed for betamethasone to act. Furthermore, all patients may benefit from close fetal monitoring before delivery because of the high rate of intervention for deteriorating fetal status.

Maternal plasma corticotropin-releasing hormone associated with stress at 20 weeks' gestation in pregnancies ending in preterm delivery

OBJECTIVE

This study tested the hypothesis that maternal stress is associated with elevated maternal levels of corticotropin releasing hormone and activation of the placental-adrenal axis before preterm birth.

STUDY DESIGN

In a behavior in pregnancy study, 524 ethnically and socioeconomically diverse women were followed up prospectively and evaluated at 3 gestational ages: 18 to 20 weeks, 28 to 30 weeks, and 35 to 36 weeks. Maternal variables included demographic data, medical conditions, perceived stress level, and state anxiety. Maternal plasma samples were collected at each gestational age. Eighteen case patients with spontaneous onset of preterm labor were matched against 18 control subjects who were delivered at term, and their samples were assayed for corticotropin-releasing hormone, adrenocorticotropic hormone, and cortisol by means of radioimmunoassay. Statistical tests were used to examine mean differences in these hormones. In addition, the relationship between stress level and each hormone was tested with a Pearson correlation coefficient and hierarchic multiple regressions in each group.

RESULTS

Patients who had preterm delivery had significantly higher plasma corticotropin-releasing hormone levels than did control subjects at all 3 gestational ages (P <.0001). Analyses did not find any differences in reported levels of stress between 18 to 20 weeks' gestation and 28 to 30 weeks' gestation. A hierarchic multiple regression indicated that maternal stress level at 18 to 20 weeks' gestation and maternal age accounted for a significant amount of variance in corticotropin-releasing hormone at 28 to 30 weeks' gestation, after controlling for corticotropin-releasing hormone at 18 to 20 weeks' gestation (P <. 001). In addition, patients who were delivered preterm had significantly elevated plasma levels of adrenocorticotropic hormone at all 3 gestational ages (P <.001) and significantly elevated cortisol levels at 18 to 20 weeks' gestation and 28 to 30 weeks' gestation (P <.001).

CONCLUSION

Maternal plasma levels of corticotropin-releasing hormone are significantly elevated at as early as 18 to 20 weeks' gestation in women who are subsequently delivered preterm. Changes in corticotropin-releasing hormone between 18 to 20 weeks' gestation and 28 to 30 weeks' gestation are associated with maternal age and stress level at 18 to 20 weeks' gestation. Maternal stress and corticotropin-releasing hormone levels may be potential markers for the patient at risk for preterm birth. Activation of the placental maternal pituitary-adrenal axis is consistent with the classic endocrine response to stress.

Open clinical study of the efficacy and safety of terbinafine cream 1% in children with tinea corporis and tinea cruris

BACKGROUND

Topical application of antifungal agents is considered the treatment of choice for dermatomycoses. Most of the available drugs are fungistatic, requiring long term treatment to prevent relapses. Terbinafine is a synthetic antifungal agent that, because of its fungicidal action, provides high cure rates and low relapse rates after short periods of treatment.

METHODS

Ninety-seven children ages 2 to 15 years with a suspected diagnosis of tinea corporis and/or tinea cruris were enrolled in this open trial. After mycologic assessment to confirm diagnosis (culture and direct microscopy) terbinafine 1% cream was applied once daily during 1 week. Clinical and mycologic assessments were made at the baseline visit and on Days 7, 14 and 21. Efficacy assessment was based on 88 children (9 patients excluded by protocol violation).

RESULTS

Therapy was considered effective in 92.0% (81 of 88) of patients (complete clinical and mycologic cure or mycologic cure with minimum signs and symptoms or clinical improvement, > or = 50%). Tolerability was assessed in 97 patients on an intention-to-treat basis. Adverse reactions were itching 3% (3 of 97), itching associated with erythema exacerbation 1% (1 of 97) and contact dermatitis 1% (1 of 97).

CONCLUSION

Terbinafine 1% cream appears to be an effective and well-tolerated treatment for tinea corporis and tinea cruris in children.

Long-term nitric oxide blockade in the pregnant rat: effects on blood pressure and plasma levels of endothelin-1

OBJECTIVE

Abnormalities in the production of nitric oxide and endothelin-1 have been implicated in the development of preeclampsia. We postulated that long-term nitric oxide synthase inhibition with L-nitro-arginine methyl ester would induce sustained hypertension, a rise in plasma levels of endothelin-1, and fetal growth restriction.

STUDY DESIGN

Conscious virgin and pregnant Sprague-Dawley rats received infusions of vehicle or L-nitro-arginine methyl ester (2.5 mg/kg/hr) for 11 days. Mean arterial pressure was assessed serially. On day 21 of gestation (or equivalent in virgin rats) plasma was collected for endothelin-1 levels; pup weight and litter size were determined. Data were analyzed with analysis of variance and regression techniques.

RESULTS

Mean arterial pressure was constant in virgin control rats (n = 7) but declined in pregnant control rats (n = 11) as gestation advanced. Nitric oxide synthase inhibition in virgin (n = 10) and pregnant (n = 11) rats caused sustained elevations in mean arterial pressure (165 +/- 7 vs 100 +/- 3 mm Hg, L-nitro-arginine methyl ester vs control virgin rats, p < 0.0001; 149 +/- 5 vs 91 +/- 2 mm Hg, L-nitro-arginine methyl ester vs control pregnant rats, p < 0.0001). L-nitro-arginine methyl ester induced a rise in plasma endothelin-1 levels in virgin (4.4 +/- 0.1 vs 3.5 +/- 0.1 pg/ml, L-nitro-arginine methyl ester vs control, p < 0.0001) and pregnant rats (3.0 +/- 0.1 vs 2.6 +/- 0.1 pg/ml, L-nitro-arginine methyl ester vs control, p < 0.0001). Pregnant rats had lower endothelin-1 levels than did virgin rats (p < 0.0001). Mean arterial pressure and endothelin-1 were significantly correlated in pregnant rats. L-nitro-arginine methyl ester decreased pup weight (2.4 +/- 0.4 vs 3.7 +/- 0.2 gm/pup/litter, L-nitro-arginine methyl ester vs control, p < 0.01) and litter size (6.6 +/- 1.3 vs 10.2 +/- 0.9 pups/litter, L-nitro-arginine methyl ester vs control, p < 0.05).

CONCLUSIONS

Long-term nitric oxide synthase blockade causes sustained hypertension, elevated levels of endothelin-1, and fetal growth restriction. Although the endocrine and pressor effects are not unique to pregnancy, this model clearly induces some of the changes seen in preeclampsia and may be useful for studying specific interventions.

Adenosine modulates hypoxia-induced atrial natriuretic peptide release in fetal sheep

The effects of adenosine on atrial natriuretic peptide (ANP) secretion were determined in chronically catheterized fetal sheep (> 0.8 term). Adenosine was infused into the the right jugular vein for 1 h at 8 +/- 0.4 (5 fetuses), 160 +/- 8 (6 fetuses), and 344 +/- 18 micrograms.min-1.kg estimated fetal wt-1. Fetal arterial blood gases and pH were generally unaffected by adenosine, although mean arterial CO2 tension increased transiently by 2-5 Torr and pH fell progressively during the highest rate of infusion. During the intermediate and high infusion rates, fetal hemoglobin concentrations increased by 11-13% and mean fetal heart rate rose by 18% from a control value of approximately 167 beats/min. Mean arterial pressure was not affected during adenosine infusion. Adenosine significantly increased fetal plasma ANP levels, with maximum concentrations 1.80, 2.36, and 2.51 times greater than control means (142-166 pg/ml) for the respective infusion rates of 8, 160, and 344 micrograms.min-1.kg estimated fetal wt-1. In seven fetuses, reducing fetal arterial O2 tension by approximately 9-10 Torr from a control of 23 +/- 1.3 Torr increased plasma ANP concentrations approximately 2.4 times the control mean of 176 pg/min. Adenosine-receptor blockade with 8-(p-sulfophenyl)-theophylline reduced by 50% the maximum hypoxia-induced rise in plasma ANP concentrations. It is concluded that adenosine causes a dose-dependent rise in fetal plasma ANP concentrations and modulates fetal ANP release during hypoxia.

Plasma levels of atrial natriuretic peptide in normal and hypertensive pregnancies: a meta-analysis

OBJECTIVE

Our goals were (1) to use meta-analysis to determine whether pregnancy and the puerperium are accompanied by alterations in plasma atrial natriuretic peptide levels when compared with the nonpregnant state and (2) to evaluate the additional effects of hypertensive disease during pregnancy on plasma atrial natriuretic peptide levels.

STUDY DESIGN

Articles measuring atrial natriuretic peptide levels during pregnancy were reviewed. Data from articles meeting inclusion criteria were abstracted, and a meta-analysis was performed with the use of the maximum likelihood methods of Jennrich and Schluchter (Biometrics 1986;42:805-20).

RESULTS

The mean atrial natriuretic peptide level in nonpregnant control subjects was 28.7 pg/ml (95% confidence interval 22.5 to 36.7). The mean plasma atrial natriuretic peptide level rose 41% to 40.5 pg/ml (95% confidence interval 31.7 to 51.8) in the third trimester (p < 0.0001). It was 71.1 pg/ml (95% confidence interval 51.2 to 98.7) or 148% greater than the mean nonpregnant level during the first week post partum (p < 0.0001). Compared with levels in pregnant control subjects, plasma atrial natriuretic peptide levels increased 52% to 52.1 pg/ml (95% confidence interval 32.9 to 82.5) in women with gestational hypertension (p < 0.005) and 130% to 78.8 pg/ml (95% confidence interval 52.3 to 118.8) in women with preeclampsia (p < 0.0001). Chronic hypertension did not significantly alter atrial natriuretic peptide levels.

CONCLUSIONS

The 41% increase in atrial natriuretic peptide levels in the third trimester suggests that atrial stretch receptors sense the expanded blood volume as normal to moderately increased. The rise in atrial natriuretic peptide during the first week post partum is consistent with known hemodynamic changes and suggests that atrial natriuretic peptide may be involved in the postpartum diuresis. The marked increase in plasma atrial natriuretic peptide levels observed in preeclampsia is not likely to result from elevated arterial pressures alone but may reflect underlying factors unique to this disease process.

Effect of hemodialysis on uterine and umbilical artery Doppler flow velocity waveforms

A case of a pregnant woman with membranous glomerulonephropathy requiring hemodialysis is described. During hemodialysis the patient underwent Doppler flow studies of the uterine and umbilical arteries. In spite of avoidance of hypotension and major fluid shifts, hemodialysis was accompanied by a significant increase in the systolic/diastolic ratio of the proximal uterine artery. There was no significant change in the umbilical artery systolic/diastolic ratio.

Atrial natriuretic peptide metabolism during pregnancy in the rat

OBJECTIVE

Our purpose was to determine whether plasma clearance rates and production rates of atrial natriuretic peptide 99-126 are altered during pregnancy in the rat.

STUDY DESIGN

Twelve virgin and 12 late-pregnant chronically instrumented, conscious, unrestrained Sprague-Dawley rats were studied. Mean arterial pressure, heart rate, and plasma atrial natriuretic peptide levels were measured before and during a 40-minute continuous infusion of atrial natriuretic peptide (10 ng/kg/min).

RESULTS

Control mean arterial pressure was 106 +/- 5 mm Hg in virgin rats versus 97 +/- 4 mm Hg in pregnant rats. Atrial natriuretic peptide infusion did not significantly affect mean arterial pressure in either group of animals but decreased heart rate in virgin rats. Basal plasma atrial natriuretic peptide levels were significantly higher in virgin than in pregnant rats (107 +/- 10 vs 78 +/- 7 pg/ml, respectively, p < 0.05). Atrial natriuretic peptide infusion significantly increased plasma levels in both groups to similar (183 +/- 19 and 154 +/- 14 pg/ml, virgin vs pregnant rats). Calculated plasma clearance rates were similar in virgin and pregnant rats (166 +/- 27 vs 155 +/- 17 ml/kg/min). Estimated production rates of atrial natriuretic peptide were higher in virgin then in pregnant rats (15.1 +/- 1.4 vs 11.4 +/- 1.1 ng/kg/min, p < 0.05).

CONCLUSIONS

Plasma atrial natriuretic peptide levels are lower in chronically instrumented near-term pregnant rats compared with levels in virgin rats. This is not related to differences in plasma atrial natriuretic peptide clearance rates but rather to a decrease in production rates in late pregnancy.

Cigarette smoking during pregnancy: acute effects on uterine flow velocity waveforms

OBJECTIVE

To determine the acute effects of smoking during pregnancy on selected characteristics of the flow velocity waveform of the uterine artery.

METHODS

We studied 19 chronic smokers at a mean (+/- standard error) gestational age of 28 +/- 1 weeks. After informed consent was given, the uterine artery was located using ultrasound imaging with color flow mapping. The characteristic waveform was imaged by pulsed Doppler ultrasonography. Maternal heart rate and blood pressure and the systolic-diastolic ratio (S/D) and resistance index of the uterine artery were measured before (-10 and -1 minutes), during (+5 and +10 minutes), and after (+20 and +30 minutes) smoking two standard cigarettes in succession.

RESULTS

Maternal heart rate increased 27%, systolic blood pressure increased 8%, and diastolic blood pressure increased 19% with smoking (P < .001). The uterine artery S/D and resistance index decreased from 2.33 to 2.02 and from 0.55 to 0.49, respectively (P < .001).

CONCLUSION

The acute effects of smoking on maternal systemic hemodynamics probably influence the flow velocity waveform of the uterine artery and preclude any definitive interpretation of acute changes in downstream resistance.

Effect of pregnancy on the vasodepressor response to atrial natriuretic factor

OBJECTIVE

We attempted to determine whether pregnancy alters the vasodepressor response to both physiologic and pharmacologic infusions of atrial natriuretic factor 99-126.

STUDY DESIGN

Ten virgin and 10 pregnant (17 +/- 1 days of gestation) conscious, unrestrained Sprague-Dawley rats with chronic indwelling vascular catheters were studied. Mean arterial pressure and heart rate were measured in response to steady-state infusions of either saline solution or increasing concentrations of atrial natriuretic factor (range 5 to 2560 ng.kg-1.min-1).

RESULTS

Basal mean arterial pressure was significantly lower in pregnant rats than in virgin rats (89 +/- 3 vs 97 +/- 2 mm Hg, p < 0.02). Atrial natriuretic factor induced significant dose-dependent decreases in mean arterial pressure and heart rate in virgin and pregnant rats (p < 0.001). The hypotensive effects of atrial natriuretic factor were blunted in the pregnant rats only in response to the highest concentrations of atrial natriuretic factor administered (-27 +/- 3 mm Hg in pregnant rats vs -43 +/- 3 mm Hg in virgin rats, p < 0.005).

CONCLUSIONS

The vasodepressor response to physiologic infusions of atrial natriuretic factor was not affected by pregnancy status. However, pharmacologic infusions of atrial natriuretic factor resulted in a blunted vasodepressor response in the pregnant animals. This may be due to alterations in vascular atrial natriuretic factor receptors, changes in the clearance rate of atrial natriuretic factor, or the modulating effects of other vasoactive hormones.

Maternal tobacco use and substance abuse: reported prevalence rates and associations with the delivery of small for gestational age neonates

OBJECTIVE

To determine the changes in reported prevalence rates of tobacco use and substance abuse in a population of pregnant women, as well as to evaluate the associations between such use and sociodemographic characteristics and the delivery of small for gestational age (SGA) neonates.

METHODS

We studied 7741 women who delivered at Cedars-Sinai Medical Center from 1986-1990. Antenatal and delivery information was entered prospectively into the computerized perinatal data base. Subjects were classified according to tobacco use and substance abuse status. We defined SGA as a birth weight less than the tenth percentile for gestational age at delivery. Univariate and multivariate analyses were used to determine the associations between SGA and tobacco use, substance abuse, and sociodemographic characteristics.

RESULTS

We found that the reported prevalence rates of tobacco use and substance abuse declined between 1986-1990 (10 versus 6% and 7 versus 2%, respectively; P < .001). Tobacco use and substance abuse were reported as being highest in black women (11 and 6%) and lowest in Asian and Hispanic women (4 and 3%), a significant difference (P < .001). Tobacco use and race-ethnicity were found to have the strongest independent associations with SGA. The incidence of SGA was highest in black women identified as tobacco users and substance abusers.

CONCLUSIONS

The reported rates of tobacco use and substance abuse varied by year, race-ethnicity, and insurance status. There were significant associations between maternal tobacco use, substance abuse, and race-ethnicity and the incidence of SGA neonates.

The biophysical profile in labor

To determine whether the biophysical profile would be a valuable intrapartum addition to fetal heart rate monitoring in predicting umbilical arterial acid-base status at delivery, 95 patients at term had serial studies during labor and umbilical artery blood gas analysis. There was no significant association between biophysical profile score and cord blood pH, nor was there a difference in scores between the acidemic and nonacidemic groups. Of the five components of the initial biophysical profile, only a nonreactive nonstress test (NST) was associated with both pH 7.20 or less (P = .019) and metabolic acidemia (P = .016). None of the individual variables of the final examination correlated with a pH of 7.20 or less. However, a nonreactive NST was associated with metabolic acidemia (P = .03), as was the presence of breathing (P = .03). Of the ten infants with pH 7.20 or less, eight had an initial and five had a final biophysical profile score of 8 or higher. Of the five whose pH was less than 7.15, four had an initial and three a final score of 8 or more. Finally, of the five with metabolic acidemia, four had an initial and two a final score of 8 or higher. Half of the acidemic fetuses had final biophysical profile scores of 8 or higher, suggesting that this score in labor is not reliable to rule out acidemia at delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Perinatal outcome in triplet versus twin gestations

The present study was conducted to determine whether triplet pregnancies are associated with a significantly worse perinatal outcome than twin pregnancies. Maternal and neonatal outcome was evaluated in 15 triplet and twin pregnancies that were matched for maternal age, race, type of medical insurance, delivery mode, parity, and history of previous preterm delivery. Preterm labor occurred significantly more often in triplet than in twin gestations (80 versus 40%), as did preterm delivery (87 versus 26.7%). Triplets had a significantly lower mean birth weight (1720 versus 2475 g) and gestational age at delivery (33 versus 36.6 weeks). In addition, 53.3% of triplet pregnancies but only 6.7% of twin pregnancies had one or more neonates with intrauterine growth retardation. Discordancy also occurred more frequently in triplets than in twins (66.7 versus 13.3%). The mean averaged neonatal hospital stay was significantly higher in triplets (29 versus 8.5 days), and triplets had a fivefold increased risk of requiring neonatal intensive care as compared with twins. However, there were no significant differences between the groups in maternal morbidity or major neonatal complications such as respiratory distress syndrome or intraventricular hemorrhage. We believe that these data will be useful in counseling patients with respect to the anticipated perinatal outcome of triplet pregnancies.

Atrial natriuretic factor: the effects of pregnancy and a high-salt diet on atrial levels

The chronic and relatively acute changes in blood volume that occur during pregnancy and post partum may be associated with alterations in the content of atrial natriuretic factor in the atria. We measured the concentration of atrial natriuretic factor in the right and left atria of virgin, pregnant, and postpartum Sprague-Dawley rats by radioimmunoassay as well as the concentration of atrial natriuretic factor in the atria and plasma of term pregnant rats on a high-salt diet. Neither right nor left atrial concentrations of atrial natriuretic factor were elevated during pregnancy in animals on a normal diet, but both were increased during the first 2 days after delivery. Term pregnant rats on a high-salt diet showed a small increase in atrial natriuretic factor levels in the left atria only, without any change in plasma atrial natriuretic factor levels. We conclude that relatively acute changes in fluid and electrolyte balance are more likely than chronic ones to be associated with alterations in atrial natriuretic factor concentrations in the atria.

Perinatal factors influencing atrial natriuretic peptide levels in umbilical arterial plasma at the time of delivery

Little is known about atrial natriuretic peptide metabolism or secretion in the human fetus. The purpose of this study was to determine if both the placenta and umbilical vessels are possible sites of atrial natriuretic peptide metabolism and to evaluate the effects that labor, route of delivery, prolonged pregnancy, preeclampsia, and fetal distress have on umbilical arterial atrial natriuretic peptide levels. We found that plasma atrial natriuretic peptide levels in the umbilical artery are significantly greater than those in the vein (p less than 0.001). Umbilical arterial and umbilical venous atrial natriuretic peptide levels were higher in plasma samples collected immediately at delivery when compared with those obtained 10 minutes later (p less than 0.001). Umbilical arterial atrial natriuretic peptide levels were elevated in pregnancies complicated by preeclampsia and fetal distress (p less than 0.01). Labor, route of delivery, and prolonged pregnancy had no effect on umbilical arterial atrial natriuretic peptide levels. We propose that both the placenta and umbilical vessels contain atrial natriuretic peptide receptors that are involved in the clearance or metabolism of atrial natriuretic peptide. The increased umbilical arterial atrial natriuretic peptide levels present in preeclampsia and fetal distress may reflect an attempt by the fetus to regulate blood flow.

Plasma atrial natriuretic peptide levels during the rat estrous cycle, pregnancy, and puerperium

The rat has been used as a model for studying the changes that occur in maternal blood volume and renal function during pregnancy. The role, if any, that atrial natriuretic peptide plays in regulating these changes is unknown, and little information is available on atrial natriuretic peptide levels at different stages of gestation in the rat. In this study we measured plasma atrial natriuretic peptide levels by radioimmunoassay in the rat at each stage of the estrous cycle, during the last 2 weeks of pregnancy, and in the early postpartum period. Atrial natriuretic peptide levels did not change during the estrous cycle. Atrial natriuretic peptide levels were low on days 10 to 15 of gestation but rose to become significantly higher than nonpregnant levels on days 16 to 18. On day 21 shortly before delivery, levels were similar to nonpregnant values. Postpartum, atrial natriuretic peptide levels rose immediately and remained elevated for the next 48 hours. These findings suggest that factors other than blood volume may mediate plasma atrial natriuretic peptide levels during pregnancy and the postpartum period.