Maternal infection-induced white matter injury is reduced by treatment with interleukin-10

OBJECTIVE

The purpose of this study was to test the hypothesis that interleukin-10 can prevent white matter injury in neonatal rats that are born to infected dams.

STUDY DESIGN

Timed pregnant rats (day 17) were assigned to the following treatment groups: (1) saline control (n = 5 rats), (2) Escherichia coli- infected (n = 10 rats), and (3) E coli + interleukin-10 (n = 5 rats). E coli was administered at a titer of 1 x 10(7) colony-forming units by intrauterine inoculation just above the cervix at the bifurcation of the uterine horns. Rat interleukin-10 was administered intravenously at a dose of 1 microg/kg of body weight. After delivery, the pups were maintained with dams until day 8, at which time they were placed under general anesthesia and perfused with saline solution followed by 10% paraformaldehyde. The brains were removed, placed in 30% sucrose solution, and then frozen at -20 degrees C until the preparation of the frozen sections. Standard hematoxylin/eosin staining was performed, and the brains were evaluated for matter necrosis, apoptotic cells, and ventricular swelling.

RESULTS

In pups that were born to infected dams, 11 of 38 pups (29%) displayed symmetric lesions around the lateral ventricles. These lesions were characterized by marked looseness/edema of the neuropil, foamy-appearing histiocytes, and granular neuropil breakdown. None of the pups (n = 17) that were born to interleukin-10-treated infected dams displayed this pattern of severe white matter injury.

CONCLUSION

These results suggest that maternal interleukin-10 therapy could provide neuroprotection for infants who are born to mothers with intrauterine infection.

Emergency cesarean delivery for nonreassuring fetal heart rate tracings. Compliance with ACOG guidelines

OBJECTIVE

To review the English-language literature from 1990 to 2000 on cesarean delivery for "fetal distress" and assess compliance with American College of Obstetricians and Gynecologists (ACOG) guidelines.

STUDY DESIGN

A PubMed search with the search items cesarean, fetal distress, cesarean, nonreassuring fetal heart rate, cesarean, neonatal acidosis and cesarean, umbilical arterial pH was undertaken. Excluded from the search were case reports, letters to the editor, focus on fetal anomaly, combinations with other reasons for operative delivery (either abdominally or vaginally) or absence of pertinent information.

RESULTS

Among 392 articles from the search, 169 met the inclusion criteria. Three reports provided detailed information on use of scalp pH; use occurred in 5% (60/1,128) of emergency cesareans. Three reports provided data on the use of tocolytics for intrauterine resuscitation; the combined result was 16% (201/1,261). Five reports assessed the decision-to-incision interval within 30 minutes; in 59% (262/446) of cases it was achieved. Five reports contained cord pH information on 340 emergency cesarean deliveries; umbilical arterial pH was < 7.00 in 10%.

CONCLUSION

Physician use of, and compliance with, ACOG guidelines for emergency cesarean deliveries is difficult to assess, and incomplete compliance appears commonplace.

Maternal benefit of high-dose intravenous corticosteroid therapy for HELLP syndrome

OBJECTIVE

We compared maternal outcomes for patients with HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome treated with or without high-dose corticosteroids to ameliorate maternal disease.

STUDY DESIGN

An analysis of data for patients with HELLP syndrome (platelets, <or=100,000/microL; lactate dehydrogenase level, >or=600 IU/L; aspartate aminotransferase and/or alanine aminotransferase level, >or=70 IU/L) who were treated during the 7-year epochs before and after the clinical trials in 1992 and 1993 demonstrated maternal benefit with high-dose dexamethasone.

RESULTS

Corticosteroid use increased from 16% (39/246 patients) for fetal indication from 1985 to 1991 to 90% (205/228 patients) for maternal-fetal indications from 1994 to 2000. Significantly reduced composite maternal disease from 1994 to 2000 was evidenced by improvements in laboratory parameters, disease progression to class 1 HELLP syndrome, the degree of hypertension, the need for antihypertensive therapy, the use of transfusion, and the presence of maternal morbidity (P<.05). Indices of postpartum recovery also were shortened significantly (P<.001).

CONCLUSION

Routine early initiation of high-dose intravenous corticosteroids for patients with HELLP syndrome significantly lessened maternal disease, reduced maternal morbidity, and expedited recovery.

Maternal and perinatal complications with uterine rupture in 142,075 patients who attempted vaginal birth after cesarean delivery: A review of the literature

OBJECTIVE

The purpose of this study was to determine the rate of uterine rupture and its complications as the result of trial of labor after previous cesarean delivery.

STUDY DESIGN

PubMed was searched from 1989 to 2001, with the terms "VBAC, uterine rupture," "trial of labor, uterine rupture," "cesarean delivery, uterine rupture," and "scarred uterus, rupture." For inclusion, reports had to contain data from at least 100 patients with trials of labor that included a description of adverse outcomes. Duplicate reporting from a single institution was excluded. Odds ratios and 95% CIs were calculated.

RESULTS

Seventy-two of the 361 articles (20%) that were identified met the inclusion criteria. A 6.2 per 1000 trial of labor rate of uterine rupture (total=880 uterine ruptures in 142,075 trials of labor) was determined. For every 1000 trials of labor the uterine rupture-related complication rate was 1.8 for packed red blood cell transfusion, 1.5 for pathologic fetal acidosis (cord pH<7.00), 0.9 for hysterectomy, 0.8 for genitourinary injury, 0.4 for perinatal death, and 0.02 for maternal death. The perinatal mortality rate was significantly lower among studies from the United States versus other countries (0.3 vs 0.6; odds ratio, 0.50; 95% CI, 0.26-0.94) and in series that exceeded 1000 patients (0.2 vs 1.7; odds ratio, 7.34; 95% CI, 3.94-13.69).

CONCLUSION

Although relatively uncommon, uterine rupture is associated with several adverse outcomes, depending on the time of the publication and the site and size of the population that was studied.

Predictability of intrapartum and neonatal outcomes with the amniotic fluid volume distribution: a reassessment using the amniotic fluid index, single deepest pocket, and a dye-determined amniotic fluid volume

OBJECTIVE

The purpose of this study was to establish whether ultrasound-estimated or dye-determined amniotic fluid distribution (upper compared with lower quadrant) is predictive of perinatal outcome.

STUDY DESIGN

Amniotic fluid distribution as measured by the amniotic fluid index, single deepest pocket, and dye-determined volumes was ascertained and correlated with intrapartum and neonatal outcomes.

RESULTS

Between January 1997 and January 2001, 135 women (70 upper-greater and 65 lower-greater) participated in this prospective observational study. The sum of the amniotic fluid index (P =.309), single deepest pocket (P =.168), and dye-determined amniotic fluid volume (P =.368) for the upper-greater compared with the lower-greater groups were similar. Decelerations in labor (P =.597), late decelerations (P =.999), cesarean deliveries for fetal distress (P =.413), and umbilical cord pH < 7.2 were similar (P =.647)

CONCLUSION

Ultrasound-estimated and dye-determined amniotic fluid volumes are similar between upper-greater and lower-greater groups, and intrapartum/neonatal outcomes are not affected by the amniotic fluid distribution.

Effect of maternal hydration on amniotic fluid volume

OBJECTIVE

To estimate the effects of maternal intravenous hydration on amniotic fluid volume in normal pregnancies.

METHODS

Women undergoing an amniocentesis for the evaluation of fetal lung maturity before an elective cesarean delivery were eligible to participate. An amniotic fluid index (AFI) was obtained before the amniocentesis, and at the time of the amniocentesis the amniotic fluid (AF) volume was determined by diazo-dye reaction with subsequent spectrophotometric analysis of AF samples. If the AF sample drawn for fetal maturity studies was mature, the patient was hydrated with 1000 mL of balanced salt solution 30 minutes before her cesarean delivery. Amniotic fluid volume was subsequently estimated after the hydration by a repeat AFI. Amniotic fluid volume was directly measured at cesarean delivery and compared with the dye-determined volume. The pre- and posthydration AFI were also compared.

RESULTS

A total of 17 women participated in the study between January 2001 and June 2001. Statistically significant increases in the AF volume and AFI were found. The prehydration median AF volume was 450 mL (range 250-953), and the median increase in AF volume was 188 mL (95% confidence interval [CI] 60, 254 mL; P <.001). Median AFI was 8.6 (range 5.8-17.8) with a median change in AFI of 1.7 cm (95% CI 1.1, 3.0; P <.001).

CONCLUSION

Maternal intravenous hydration appears to increase both the actual and ultrasound-estimated AF volumes in normal third-trimester pregnancies.

Cesarean delivery for fetal distress: rate and risk factors

The objective of this article was to review the recent English language literature on cesarean delivery for fetal distress to determine its incidence, diagnostic tests, and the contributing factors to this obstetric complications. A PubMed search (1990-2000) with items of "cesarean, fetal distress," "cesarean, non-reassuring fetal heart rate," "cesarean, neonatal acidosis," and "cesarean, umbilical arterial pH," was undertaken. Reports, letters to the editor, focus on anomalous fetuses, and papers not specifically focused on this topic were excluded. Of the 392 articles that the search yielded, 169 met the inclusion criteria. Based on 37 reports with more than 1,000 patients each, the overall risk of prompt cesarean delivery for fetal concern was 3.1% (43,340 of 13,989,74). The risk exceeded 20% in patients with moderate/severe asthma, severe hypothyroidism, severe preeclampsia, and postterm or fetal growth restricted fetuses with abnormal Doppler studies. Use of likelihood ratios suggests that Doppler of the umbilical artery is a superior diagnostic test to amniotic fluid index in identifying parturients at risk for cesarean for non-reassuring fetal heart rate tracing. Although several risk factors increase the need for cesarean delivery for fetal distress, in general, most are unpreventable.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to estimate the incidence of cesarean delivery for non-reassuring fetal heart rate tracing, outline potential diagnostic tests that are useful for the detection of fetal distress, and summarize medical and obstetric conditions that place patients at risk for cesarean delivery for fetal distress.

Is amniotic fluid volume status predictive of fetal acidosis at delivery?

OBJECTIVE

To ascertain if dye-determined amniotic fluid volume just prior to delivery correlates with fetal acidosis at delivery.

DESIGN

The present was a prospective observational study.

SETTING

The study took place at the University of Mississippi Medical Center, Jackson MS, USA.

POPULATION

The population included 100 unlaboured women undergoing an amniocentesis for the assessment of fetal lung maturity before an elective Caesarean delivery between January 1997 and December 2000.

MAIN OUTCOMES MEASURED

The amniotic fluid volume was estimated by ultrasound measurement and quantified by dye-determined methodology immediately prior to Caesarean delivery. Umbilical cord artery pH was collected at the time of Caesarean delivery.

RESULTS

The predictive accuracy of an amniotic fluid index < or = versus > 5 to identify an umbilical artery pH of < 7.20 had a sensitivity of 0%, a specificity of 84%, and a likelihood ratio of zero. None of the dye-determined low amniotic fluid volumes were identified using the single deepest pocket technique. Dye-determined low, normal, and high amniotic fluid volume groups contained a similar number of fetuses with umbilical cord arterial pH < 7.20 (P = 0.371), < 7.10 (P = 0.460), and < 7.00 (P = 0.614). Receiver-operating characteristic curves could not identify any amniotic fluid index from 0 to 18, single deepest pocket from 0 to 12, or dye-determined amniotic fluid volume 100-1900 mL to differentiate between the two newborns with an umbilical cord artery pH < 7 from 98 babies with cord pH > or = 7.0.

CONCLUSIONS

Neither ultrasound estimates nor dye-determined amniotic fluid volumes are predictive of a low umbilical artery pH at delivery.

Evaluation of a rat model of preeclampsia for HELLP syndrome characteristics

OBJECTIVE

To determine whether a rat model of preeclampsia includes features consistent with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome.

METHODS

Preeclampsia was induced experimentally in timed-pregnant Sprague-Dawley rats using the reduced uterine perfusion pressure (RUPP) model. On day 14 of gestation, silver clips were placed around the aorta below the renal arteries and on the left and right uterine arcade at the ovarian artery. All animals were chronically instrumented to determine conscious blood pressure and to obtain blood samples for analysis of complete blood count, platelet count, liver function tests, uric acid, creatinine, and albumin. Blood samples were collected and animals sacrificed on day 19 of gestation, at which time placental and pup weight were obtained. A control group was analyzed similarly. Statistical analysis was performed with the Student t test.

RESULTS

The RUPP model animals (n = 8), when compared with the normotensive controls (n = 9), did not show a statistically significant difference in hemoglobin, platelets, liver function tests, uric acid, creatinine, or albumin, although the mean arterial pressure was higher (mean +/- SD 131.9 +/- 17.1 mmHg versus 104.0 +/- 14.0 mmHg, respectively; P = .003) and pup number was lower (RUPP 6.6 +/- 2.4 versus control 13.8 +/- 2.3, P < .001).

CONCLUSION

Although decreased uteroplacental perfusion induces changes similar to symptoms of preeclampsia, the RUPP rat model does not appear to express features of HELLP syndrome.

Dexamethasone compared with betamethasone for glucocorticoid treatment of postpartum HELLP syndrome

OBJECTIVES

To compare the efficacy of dexamethasone and betamethasone to ameliorate the course of postpartum hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome.

METHODS

A prospective, mixed randomized/non-randomized clinical investigation of patients with postpartum HELLP syndrome. Treatment with either dexamethasone or betamethasone was continued until there was evidence of disease recovery.

RESULTS

Baseline characteristics of both the dexamethasone (n=18) and betamethasone (n=18) groups were similar. Although the time to discharge from the obstetrical recovery room was not statistically significant between groups, reduction in mean arterial blood pressure was more pronounced in the dexamethasone group as compared with the betamethasone group (-15.3+/-1.4 mmHg vs. -7.5+/-1.4 mmHg, respectively, P<0.01). Patients in the dexamethasone group required less antihypertensive treatment than the betamethasone group (6% vs. 50%, P=0.01) and also had a decreased need for readmission to the obstetrical recovery room (0% vs. 22%, P=0.03).

CONCLUSION

This investigation supports the use of dexamethasone as the superior glucocorticoid to use for patients with postpartum HELLP syndrome.

Comparability of the amniotic fluid index and single deepest pocket measurements in clinical practice

Two ultrasound techniques, the amniotic fluid index (AFI) and the single deepest pocket (SDP), are currently used to detect oligohydramnios, predict variable decelerations, risk of Caesarean delivery for fetal distress, Apgar scores, umbilical cord artery pH, perinatal mortality, and cerebral palsy. Both techniques poorly identify oligohydramnios. Both techniques identify pregnancies at risk for variable decelerations, low Apgar scores, and Caesarean delivery for fetal distress. Only the SDP is predictive of a compromised fetus-umbilical artery pH, as a stand-alone test, has been correlated with perinatal mortality, and as part of the biophysical profile has been linked to cerebral palsy. This brief communication reviews the comparability of these two techniques and which method, if either, is superior in the identification of oligohydramnios, the predictability of these techniques to identify an adverse pregnancy outcome, and the ability to predict cerebral palsy and perinatal mortality.

Postpartum seizure prophylaxis: using maternal clinical parameters to guide therapy

OBJECTIVE

To use individual patient clinical parameters to signal cessation of postpartum magnesium sulfate seizure prophylaxis for the spectrum of pregnancy-related hypertensive disorders.

METHODS

This was a prospective study using clinical symptoms (absence of headache, visual changes, epigastric pain) and signs (sustained blood pressure less than 150/100 without need for acute antihypertensive therapy, spontaneous diuresis more than 100 mL per hour for no less than 2 hours) to signal cessation of intravenous magnesium sulfate postpartum in gravidas diagnosed with preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelets syndrome. Laboratory assessments (including proteinuria) were not used as criteria for drug discontinuation.

RESULTS

Five hundred three patients were enrolled and classified according to American College of Obstetricians and Gynecologists criteria (mild preeclampsia, severe preeclampsia, chronic hypertension with superimposed preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelets syndrome). Maternal age, gestational age, and hours of magnesium therapy before delivery were not statistically different among groups. There was no significant difference in the duration of postpartum magnesium sulfate therapy among groups with the median duration of therapy 4 hours (range 2-77 hours). No eclamptic seizures occurred after magnesium discontinuation. Thirty-eight patients (7.6%) required reinstitution of magnesium therapy for 24 hours because of exacerbation of blood pressure (sustained blood pressure more than 160/110) associated with headache or visual changes.

CONCLUSION

Clinical criteria, when compared with arbitrary protocols, can be used successfully to shorten the duration of postpartum magnesium sulfate administration for seizure prophylaxis in patients with pregnancy-related hypertensive disorders.

Ultrasound estimation of amniotic fluid volume using the largest vertical pocket containing umbilical cord: measure to or through the cord?

OBJECTIVES

The purpose of this investigation was to determine the preferable method, either measuring to the umbilical cord or through the umbilical cord to the base of the pocket, of ultrasonically estimating amniotic fluid volume.

SUBJECT AND METHODS

This was a prospective study carried out in singleton pregnancies undergoing a third-trimester amniocentesis. The amniotic fluid index (AFI) and single deepest pocket (SDP) were measured prior to amniocentesis. If measured spaces contained umbilical cord, measurements were made to and through the cord. Actual amniotic fluid volume was determined by the dye-dilution technique.

RESULTS

One-hundred pregnancies were evaluated. Low dye-determined volume was identified in a significantly greater number of pregnancies using the AFI to the cord (7/28, 25%) compared to through the cord (2/28, 7%) (P = 0.025). The SDP technique to the cord was superior in low volumes (2/28, 7%) vs. (0/28, 0%) through the cord (although statistical significance could not be determined because there were no low through-the-cord measurements).

CONCLUSIONS

For the detection of low amniotic fluid volumes, the AFI to the cord is better than through the cord. Measurement to the cord and through the cord had similar accuracy for both the AFI and SDP techniques in normal and high dye-determined amniotic fluid volumes.

Pregnancy after classic cesarean delivery

OBJECTIVE

To describe maternal and perinatal outcomes after a prior classic cesarean delivery.

METHODS

A retrospective review was performed including all patients from 1990-2000 whose most recent pregnancy was preceded by classic cesarean delivery.

RESULTS

During the 11-year period, there were 37,863 deliveries and 157 patients (0.4%) underwent classic cesarean operations. In the next pregnancy, one case of uterine rupture (0.6%, 95% confidence interval 0.1, 3.5) occurred at 29 weeks without preterm labor and resulted in fetal death. The prevalence of asymptomatic dehiscence was 9% (95% confidence interval 5, 15). There was no significant difference between patients with uterine dehiscence (n = 15) and patients with intact uteri (n = 141) with regard to maternal demographics, duration of labor, cervical dilatation at time of surgery, transfusion of packed red cells, bowel injury, postpartum endometritis, wound breakdown, thrombophlebitis, or umbilical arterial pH less than 7.00 (P >.05). Duration of labor, cervical dilatation, and gestational age at repeat cesarean delivery were poor predictors for uterine rupture or dehiscence.

CONCLUSION

Among patients with prior classic cesarean delivery, uterine rupture and dehiscence are neither predictable nor preventable. One in four patients will experience some form of maternal morbidity. Uterine rupture, although infrequent, can be fatal to the fetus. Uterine dehiscence, however, does not increase neonatal or peripartum maternal morbidity.

Subcutaneous stitch closure versus subcutaneous drain to prevent wound disruption after cesarean delivery: a randomized clinical trial

OBJECTIVE

The purpose of this study was to compare a subcutaneous stitch closure and subcutaneous drain placement for the risk of wound disruption after cesarean delivery.

STUDY DESIGN

This was a prospective randomized clinical trial that evaluated subcutaneous stitch closure, placement of a subcutaneous drain, or no closure for subsequent wound disruption risk in women with subcutaneous depth at >or=2 cm.

RESULTS

The maternal demographics and intrapartum risk factors for postoperative wound disruptions were similar among the 964 study subjects, who were divided into 3 groups. Wound disruptions that required opening of the wound, irrigation, debridement, packing, and/or secondary delayed closure occurred in 9.7% of the women with no closure, 10.4% of the women in the stitch closure group, and 10.3% of the women in the closed drain group (P =.834).

CONCLUSION

There appears to be no difference in the subsequent risk of wound complications when no closure of the subcutaneous tissue layers occurs versus suture closure or a closed drainage system.

Markedly elevated beta-hCG levels in a normal singleton gestation with hyperreactio luteinalis

BACKGROUND

Human chorionic gonadotropin (hCG) is produced by the trophoblast early in pregnancy and peaks at a level of approximately 100,000 IU/liter around the ninth week of gestation. Abnormally high levels are usually noted in association with multiple gestation, molar gestation, and specific ovarian or gestational malignancies.

CASES

A multiparous patient in the second trimester was referred for evaluation after a maternal triple marker screen was incalculable due to a beta-hCG level of 2.1 million IU/L. Targeted sonography revealed bilateral complex adnexal masses with a solid component of the left ovary, a normal fetus, and normal placenta. The patient underwent an exploratory laparotomy at 18 weeks' gestational age. A left oophorectomy was performed. Pathology confirmed hyperreactio luteinalis. The remainder of the pregnancy was remarkable for preterm labor and delivery at 35 weeks' gestational age. At delivery, the hCG level was noted to be 24,210 IU/L, and the fetus and placenta were normal.

CONCLUSION

Markedly elevated hCG levels rarely occur in normal singleton pregnancy and can be associated with hyperreactio luteinalis. When noted, a work-up to evaluate possible malignancy, molar gestation, and multiple gestation should be pursued.

Intra-operative haemorrhage by blunt versus sharp expansion of the uterine incision at caesarean delivery: a randomised clinical trial

OBJECTIVE

To determine whether the method used to expand the uterine incision for caesarean delivery affects the incidence of intra-operative haemorrhage.

DESIGN

A prospective randomised study of women undergoing a low segment transverse caesarean delivery. Participants were assigned to have their uterine incision either sharply or bluntly expanded.

PARTICIPANTS

Between June 1998 and June 2000, 470 women drew assignments to the sharp expansion group and 475 to the blunt group.

RESULTS

The maternal demographics of age, race, nulliparity, and body mass index as well as pre-operative haematocrit were similar between groups. Compared with the blunt group, the estimated blood loss (886 versus 843mL, P = 0.001), change in the mean haematocrit (6.1% versus 5.5%, P = 0.003), incidence of postpartum haemorrhage (13% versus 9%; relative risk = 1.23, 95% CI 1.03, 1.46) and need for a transfusion (2% versus 0.4%; relative risk = 1.65, 95% CI 1.25, 2.21) were significantly greater in the sharp group.

CONCLUSION

In caesarean delivery, sharply expanding the uterine incision significantly increases intra-operative blood loss and the need for subsequent transfusion.

Repeat postpartum magnesium sulfate administration for seizure prophylaxis: is there a patient profile predictive of need for additional therapy?

OBJECTIVE

To profile patients with hypertensive disorders of pregnancy who require reinstitution of magnesium sulfate therapy for disease exacerbation.

STUDY DESIGN

A prospective clinical trial enrolling gravidas with pre-eclampsia. The length of postpartum magnesium sulfate seizure prophylaxis was determined by individual patient characteristics. Patients with exacerbation of their disease after discontinuation of magnesium sulfate received a second course of magnesium sulfate lasting 24 h.

RESULTS

Of a total of 503 patients, 38 (7.6%) required reinstitution of postpartum magnesium sulfate therapy for an additional 24-h period. Patients with chronic hypertension complicated by superimposed pre-eclampsia were most likely to require further therapy (11/61, 18.0%), when compared with other hypertensive disorders. Additionally, patients who required reinstitution of magnesium therapy had significantly shorter gestations (32.4 +/- 4.2 weeks versus 36.3 +/- 4.2 weeks, respectively; p < 0.001), and higher mean arterial pressure during the initial magnesium course (113.2 +/- 11.2 versus 105.6 +/- 11.3 mmHg; p < 0.001).

CONCLUSION

Patients with chronic hypertension complicated by superimposed pre-eclampsia, patients delivered prior to 35 weeks' gestation and patients requiring a longer initial magnesium prophylaxis are at higher risk for the need of reinstitution of seizure prophylaxis postpartum.

Preeclampsia: pathophysiology and practice considerations for the consulting nephrologist

Abnormal placental implantation presumed to be secondary to maternal genetic susceptibility or immune maladaptation is considered to be fundamental to the pathogenesis of preeclampsia. The reduced placental perfusion resulting in placental ischemia is hypothesized to cause the known endothelial dysfunction, which leads to the clinical manifestations of this disease. Oxidative stress is a postulated linking factor, an aberration that possibly has its genesis via cytokines released from the abnormally implanted and perfused placenta. Clearly the maternal pathophysiologic changes that subsequently produce what is recognized as preeclampsia are present long before the disease makes its clinical appearance.

Postexposure prophylaxis for human immunodeficiency virus infection after sexual or injection drug use exposure: identification and characterization of the source of exposure

In a nonrandomized study of nonoccupational postexposure prophylaxis (PEP), a cross-sectional evaluation of subjects who were the source of human immunodeficiency (HIV) exposure was performed to characterize partners of index subjects seeking nonoccupational PEP against HIV. Among 401 index subjects, 64 (16%) recruited a source subject. Those in a steady relationship and those who knew that the source subject was HIV antibody positive were more likely to recruit their source subject. Source subjects reported high rates of past (78%) and current (69%) antiretroviral use; 46% of those using antiretroviral drugs had detectable plasma HIV-1 RNA levels. Antiretroviral resistance was detected in many source subjects who reported any use of antiretrovirals and was rare among source subjects who reported no history of antiretroviral use. Clinicians often make treatment decisions on the basis of incomplete knowledge of the source subject's HIV status or antiretroviral treatment history. The treatment history, particularly nonuse of a class of antiretroviral drugs, can be used to predict drug resistance.

The myth of transient hypertension: descriptor or disease process?

The objective of this study is to describe the incidence of transient hypertension and to evaluate if transient hypertension is associated with increased maternal or fetal morbidity as compared to other hypertensive disorders of pregnancy and normotensive controls. Data were collected from all deliveries at the University of Mississippi Medical Center from July 1, 1996 through January 1, 1997. Patients were grouped according to ACOG criteria for pregnancy induced hypertension. Specific maternal and fetal morbidities were compared among the groups and controls. There were 1489 deliveries during the study period. Nearly 30% of patients met the criteria for transient hypertension. There were no significant differences between patients with transient hypertension and controls in regard to maternal and fetal outcomes. Transient hypertension occurs more often than expected, however, it appears to be of limited clinical significance.