First-trimester cavum veli interpositi: prevalence and natural history.

OBJECTIVE: To confirm the identity and assess the prevalence and evolution of the fluid-filled interhemispheric midline structure, thought to be the cavum veli interpositi (CVI), in fetuses at 11-14 weeks' gestation. METHODS: This was a retrospective study of first-trimester ultrasound scans performed at a single center over 3 months. Inclusion criteria were singleton pregnancies at 11-14 weeks' gestation with known neonatal outcome. Five experts reviewed the images. Mixed-effects logistic regression and generalized estimating equations (GEE) were conducted to analyze the associations between the presence of the structure and variables including ultrasound approach (transabdominal vs transvaginal), maternal body mass index (BMI), gestational age, fetal crown-rump length (CRL) and biparietal diameter (BPD). Second-trimester ultrasound scans of the fetal central nervous system at 18-24 weeks' gestation were evaluated for the persistence of the CVI in fetuses in which the structure was observed in the first trimester. RESULTS: Of the 223 cases reviewed, 104 were included, among which the CVI was observed in 25 (24%) cases. There was no statistically significant difference in CVI visualization between transabdominal and transvaginal ultrasound examinations. GEE showed significant associations between the presence of the fetal structure and CRL (odds ratio (OR) per 10-unit increase, 1.32; P < 0.0001) and BPD (OR per 10-unit increase, 1.88; P = 0.0011). Maternal BMI and gestational age showed no significant effect on the presence of the CVI. At second-trimester follow-up of the 25 fetuses in which the CVI was observed initially, 44% still showed a CVI, 32% exhibited a cavum vergae, 4% had both structures and 20% had neither. CONCLUSIONS: Based on its anatomical location and, in some fetuses, its visualization as a distinct entity from the third ventricle, the identity of the interhemispheric midline structure in the suprathalamic region of the fetal brain between 11-14 weeks' gestation was confirmed as the CVI. The CVI and/or cavum vergae persisted into the second trimester in 80% of fetuses identified initially as having a CVI. Its presence is not linked to pathology, offering reassurance to practitioners and parents. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Early pregnancy prediction of spontaneous preterm birth before 32 completed weeks of pregnancy using plasma RNA: transcriptome discovery and initial validation of an RNA panel of markers.

OBJECTIVE: To compare the second-trimester plasma cell-free (PCF) transcriptome of women who delivered at term with that of women with spontaneous preterm birth (sPTB) at or before 32 weeks of gestation and identify/validate PCF RNA markers present by 16 weeks of gestation. DESIGN: Prospective case-control study. SETTING: Academic tertiary care centre. POPULATION: Pregnant women with known outcomes prospectively sampled. METHODS: PCF RNAs extracted from women at 22-24 weeks of gestation (five sPTB up to 32 weeks and five at term) were hybridised to gene expression arrays. Differentially regulated RNAs for sPTB up to 32 weeks were initially selected based on P value compared with control (P < 0.01) and fold change (≥1.5×). Potential markers were then reordered by narrowness of distribution. Final marker selection was made by searching the Metacore™ database to determine whether the PCF RNAs interacted with a reported set of myometrial Preterm Initiator genes. RNAs were confirmed by quantitative reverse transcription polymerase chain reaction and tested in a second group of 40 women: 20 with sPTB up to 32 weeks (mean gestation 26.5 weeks, standard deviation ±2.6 weeks), 20 with spontaneous term delivery (40.1 ± 0.9 weeks) sampled at 16-19+5  weeks of gestation. MAIN OUTCOME MEASURE: Identification of PCF RNAs predictive of sPTB up to 32 weeks. RESULTS: Two hundred and ninety-seven PCR RNAs were differentially expressed in sPTB up to 32 weeks of gestation. Further selection retained 99 RNAs (86 mRNAs and 13 microRNAs) and five of these interacted in silica with seven Preterm Initiator genes. Four of five RNAs were confirmed and tested on the validation group. The expression of each confirmed PCF RNA was significantly higher in sPTB up to 32 weeks of gestation. In vitro study of the four mRNAs revealed higher expression in placentas of women with sPTB up to 32 weeks and the potential to interfere with myometrial quiescence. CONCLUSIONS: The PCF RNA markers are highly associated with sPTB up to 32 weeks by 16 weeks of gestation. TWEETABLE ABSTRACT: Women destined for spontaneous preterm birth can be identified by 16 weeks of gestation with a panel of maternal plasma RNAs.

Perinatal outcomes in gestational diabetes: a comparison of criteria for diagnosis.

OBJECTIVE: The purpose of this study was to compare the perinatal outcomes of women after diagnosis of gestational diabetes by the current American College of Obstetricians and Gynecologists-National Diabetes Data Group recommendations with outcomes after diagnosis by the American Diabetes Association criteria. STUDY DESIGN: We identified records of 242 women who had had the standard 3-hour oral glucose tolerance test between 1995 and 1999 at the Regional Medical center in Memphis. Patients were categorized into 1 of 3 groups as follows: euglycemic control subjects (n = 69), subjects with gestational diabetes diagnosed by the National Diabetes Data Group criteria (n = 130), and subjects with gestational diabetes diagnosed by the American Diabetes Association criteria (n = 43). Maternal and infant charts were reviewed. Primary outcomes included frequency of cesarean delivery, preeclampsia, and macrosomia. In univariate analysis the chi2 test was used to compare group differences, and in multivariate analysis we used stepwise logistic regression and controlled for confounding factors. RESULTS: No differences existed among the 3 groups regarding maternal race, body mass index, history of preeclampsia, or family history of diabetes. The frequency of overall cesarean delivery, of cesarean delivery for macrosomia or arrest disorder, of preeclampsia, and of macrosomia did not differ significantly among the 3 groups. Neonatal hypoglycemia was more frequent in the groups with a diagnosis by the American Diabetes Association criteria (23.3%) and by the National Diabetes Data Group criteria (16.2%) than in the control subjects (7.2%), reaching near significance (P =.057). In the multivariate analysis, cesarean delivery for macrosomia or an arrest disorder correlated negatively with parity and positively with body mass index. Preeclampsia was associated with African American race and body mass index; macrosomia correlated with a history of macrosomia and familial diabetes. Neonatal hypoglycemia was more common in the American Diabetes Association group (odds ratio, 2.45; 95% confidence interval, 1.004-5.97) and in the insulin-requiring National Diabetes Data Group category (odds ratio, 3.71; 95% confidence interval, 1.20-11.44). CONCLUSION: The benefits of defining an additional high-risk population of women with gestational diabetes by the American Diabetes Association criteria are unclear. Further large-scale prospective clinical trials are required.

Neuropeptide Y and nitrite levels in preeclamptic and normotensive gravid women.

OBJECTIVES: Vascular tone is controlled largely by the sympathetic nervous system and is modulated by neuropeptide Y. Preeclampsia is linked to sympathetic overactivity. Nitric oxide can cause vasorelaxation of vessels or decrease sympathetic outflow by activating the baroreceptor reflex. Our purpose in this study was to compare serum levels of neuropeptide Y and nitrite levels in normotensive and preeclamptic gravid women. STUDY DESIGN: Twelve preeclamptic and 12 normotensive women matched for race, body mass index, parity, and gestational age were studied. Neuropeptide Y was measured by using a commercial radioimmunoassay. Nitric oxide was converted to nitrite by using metallic cadmium, and nitrite levels were determined spectrophotometrically by using a colorimetric assay. Data are presented as mean +/- SEM and were compared by using a t test. RESULTS: Neuropeptide Y levels were similar among preeclamptic and normotensive gravid women (33.8 +/- 3.0 and 32.2 +/- 3 pg/mL, respectively). Similarly, there were no differences in nitrite concentrations between preeclamptic and normotensive patients (11.6 +/- 0.8 vs 11.2 +/- 0.4 micromol/L, respectively). We also examined the ratios of neuropeptide Y and nitrite and found no correlation between preeclamptic and normotensive women. CONCLUSION: Peripheral levels of neuropeptide Y or nitrite do not correlate with preeclampsia. Assessment of sympathetic overactivity in preeclampsia requires an alternate model.

A randomized, controlled trial of oral and intramuscular dexamethasone in the prevention of neonatal respiratory distress syndrome.

OBJECTIVE: The study's objective was to compare the efficacies of oral and intramuscular antenatal administration of dexamethasone in reducing neonatal respiratory distress syndrome. STUDY DESIGN: Subjects at high risk for preterm delivery between 24 and 33 weeks' gestation were prospectively randomly assigned to receive either 6 mg intramuscular dexamethasone or 8 mg oral dexamethasone every 12 hours for 4 doses. The regimen was repeated weekly until 34 weeks' gestation if delivery had not yet occurred. A blinded data review was performed. The primary outcome of the trial was respiratory distress syndrome. Data were analyzed in an intent to treat fashion. Comparisons were made with an unpaired t test, chi2 or Fisher exact test, and survival analysis. P <.05 was considered significant. RESULTS: The study was discontinued at 39% enrollment after a blinded review of available outcomes. A total of 170 women with 188 fetuses were randomly assigned. The oral and intramuscular groups had similar mean gestational ages at enrollment (29.9 weeks vs 29.2 weeks) and similar median latencies (9.5 vs 10 days). No difference in the frequency of respiratory distress syndrome was found between the oral and intramuscular groups, (34.3% vs 29.8%). Neonatal sepsis (10.1% vs 1.2%, P =.01) and intraventricular hemorrhage (10.1% vs 2. 4%, P =.04) were significantly higher in the oral group. There were no statistical differences in the frequencies of necrotizing enterocolitis or neonatal death. A subgroup analysis of 112 patients who were delivered at <34 weeks' gestation revealed no statistical difference in respiratory distress syndrome between the groups; however, oral dexamethasone was associated with a significant increase in sepsis (15.9% vs 1.6%, P =.009) and intraventricular hemorrhage (15.9% vs 3.3%, P =.03). CONCLUSION: Oral administration increases neonatal morbidity without demonstrable benefit and should not at this time be used clinically for induction of fetal pulmonary maturation.

Comparison between oral and intramuscular dexamethasone in suppressing unconjugated estriol levels during the third trimester.

OBJECTIVES: Unconjugated estriol production depends on fetal adrenal androgen precursors. Fetal exposure to exogenous glucocorticoids results in adrenal suppression with a subsequent decrease in maternal serum unconjugated estriol levels. We compared the efficacy between oral and intramuscular dexamethasone in maternal serum unconjugated estriol suppression at 48 hours after the initial dose among women at risk for preterm delivery. STUDY DESIGN: Twenty-four gravidas at risk for preterm delivery were randomized to receive either 6 mg intramuscular or 8 mg oral dexamethasone every 12 hours for a total of 4 doses. Blood samples (9 mL) were obtained before the initial dexamethasone administration and again after the fourth dose. Serum was separated and frozen at -70 degreesC and subsequently underwent batch analysis. Unconjugated estriol levels were determined by radioimmunoassay with intra-assay and interassay coefficients of variation of 7.9% and 5.5%, respectively. All values are reported as mean +/- SD. The primary statistical analysis was a t test, with P <.05 considered significant. RESULTS: At the time of dexamethasone administration, gestational ages in both groups were similar. Predexamethasone and postdexamethasone unconjugated estriol levels were also similar between the intramuscular and oral groups (5.39 +/- 3.99 vs 1.80 +/- 2.49 ng/mL and 6.05 +/- 3.00 vs 1.61 +/- 1.03 ng/mL, respectively, P >.05). No difference in percent decrease in unconjugated estriol levels was found between the intramuscular (0.67 +/- 0.24) and oral (0.65 +/- 0.39) groups. CONCLUSION: Oral dexamethasone (8 mg) produces similar maternal serum unconjugated estriol suppression compared with intramuscular dexamethasone (6 mg) when evaluated 48 hours after administration.

Toxoplasmosis.

Toxoplasmosis is caused by the protozoan organism, Toxoplasma gondii. Infection with this organism primarily results from contact with infected cats and from ingestion of improperly cooked meat. Most adults with toxoplasmosis are asymptomatic. When symptoms are present, they typically resemble a mononucleosis or flulike illness. The diagnosis of toxoplasmosis in the pregnant adult is best made using serological techniques to detect IgM antibody and to document significant changes in the IgG antibody titer. Congenital toxoplasmosis usually occurs as a result of primary maternal infection. The most useful tests for confirmation of fetal infection are ultrasound examination, cordocentesis for detection of IgM-specific antibody, and amniocentesis for detection of toxoplasma DNA in amniotic fluid. Congenital toxoplasmosis can be treated with reasonable success by administration of antibiotics (spiramycin, sulfadiazine, and pyrimethamine) to the mother. In an effort to prevent acquisition of infection, pregnant women should be counseled to avoid contact with cat litter and improperly cooked beef, pork, or lamb.

Airway management of neonates with antenatally detected head and neck anomalies.

Five cases of prenatally detected neck masses that had a potential for airway obstruction at birth are described. The various options for management of the airway are discussed, including using maternal-fetal circulation until intubation, rigid bronchoscopy, tracheotomy, cyst aspiration, or extracorporeal membrane oxygen support. Congenital abnormalities involving the fetal face or neck are extremely rare. With technical advances in ultrasonography, these masses were first noted on prenatal ultrasound in the late 1970s. Before that period, they were detected at delivery. These masses are solid or cystic and may cause asphyxia because of airway obstruction at the time of delivery. The survivability of these neonates without immediate intervention at birth is 0% to 20%. If a neck mass is detected in the fetus by prenatal ultrasonography, then a strategic plan for these types of cases should be developed early in the prenatal period. The airway management plan should be tailored for each individual case. Coordination and the expertise of an obstetrician, neonatologist, anesthesiologist, and pediatric otolaryngologist are needed to manage these complex situations.

Cerebrovascular disorders complicating pregnancy--beyond eclampsia.

OBJECTIVE: Our purpose was to investigate the problems encountered in the diagnosis and management of cerebrovascular disorders associated with pregnancy and the puerperium. STUDY DESIGN: Pregnancies complicated by cerebrovascular disorders were identified by retrospective chart review (1985 to 1995). Events associated with trauma, neoplasm, drug ingestion, and infection were excluded. RESULTS: The study population comprised 24 women with a variety of cerebrovascular disorders: 14 with infarction (5 arterial, 9 venous), 6 with intracranial hemorrhage (3 anatomic malformation, 3 unknown etiology), 3 with hypertensive encephalopathy, and 1 with an unruptured aneurysm. Blood pressure reflected physical condition at presentation and did not predict diagnosis or outcome except in the 3 women with hypertensive encephalopathy. Only 4 of 14 women with infarction and 1 of 6 with intracranial hemorrhage had a diastolic blood pressure > or = 110 mm Hg. Presumption of eclampsia delayed the diagnosis in 10 women (41.7%). In addition, patient delay in seeking medical attention complicated 10 cases. After review, none of the adverse maternal outcomes were deemed preventable by earlier physician intervention. Seven maternal deaths occurred (29.2%). Neonatal outcome was related to the gestational age and the maternal condition at presentation. CONCLUSION: Cerebrovascular disorders are an uncommon and unpredictable complication of pregnancy that are associated with substantial maternal and fetal mortality. Suspected eclampsia unresponsive to magnesium sulfate therapy warrants an immediate neuroimaging study. Interestingly, in women with intracranial hemorrhage, severe hypertension was not an associated predictive factor.

A comparison of the bioavailability of oral and intramuscular dexamethasone in women in late pregnancy.

OBJECTIVE: To compare the bioavailability of oral and intramuscular (i.m.) dexamethasone in third-trimester pregnant women. METHODS: Oral and i.m. dexamethasone levels were compared in a randomized, parallel, crossover bioavailability study involving 11 gravid women in the third trimester of pregnancy. Subjects were randomized to receive either 6 mg of i.m. or 8 mg of oral dexamethasone. The following week, the alternative regimen was administered. Serial blood samples were obtained after drug administration. Dexamethasone concentrations were measured by radioimmunoassay. Total area under the curve was compared for the oral and i.m. groups using a paired t test. RESULTS: Eight of the 11 women completed the study through 12 hours; all 11 women completed the study through 6 hours. Among the 11 women, peak levels of dexamethasone occurred 30 minutes after i.m. injection (mean +/- standard deviation, 101.7 +/- 19.2 ng/mL) and 120 minutes after oral administration (65.9 +/- 20.5 ng/mL). Area under the curve did not differ significantly between those receiving i.m. dexamethasone (258.3 +/- 50.0 ng/minute/mL) and those receiving oral dexamethasone (251.8 +/- 59.7 ng/minute/mL) when measured 6 hours after administration of the drug. Terminal half-lives were similar in the i.m. and oral groups. Similar findings were noted among the eight women who were studied through 12 hours. This study had a power of 87% to detect a 20% difference in area under the curve between the two groups. CONCLUSION: The bioavailability of 8 mg of oral dexamethasone is similar to that of a 6-mg IM dose, as determined by the area under the curve.

Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome in pregnancy: review of 11 cases.

OBJECTIVE: Little information exists regarding thrombotic thrombocytopenic purpura and hemolytic uremic syndrome during pregnancy. We report a series of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome complicating pregnancy, with emphasis on diagnosis and management of this rare disorder. STUDY DESIGN: Between January 1988 and February 1996, 11 women with either thrombotic thrombocytopenic purpura (n = 8) or hemolytic uremic syndrome (n = 3) were evaluated. Clinical and laboratory findings and maternal and neonatal outcomes were recorded from the medical records. RESULTS: Eight of the 11 women were in the third trimester or peripartum period, and three were seen before fetal viability. Treatment included fresh-frozen plasma in all women, plasmapheresis (n = 8), packed red blood cells (n = 9), and platelet transfusions (n = 5); 1 patient required splenectomy. There were two maternal deaths. Of the 9 surviving women, 4 had chronic renal disease, 1 of whom also had residual neurologic deficit. Preterm delivery occurred in 5 of 8 pregnancies continuing beyond 20 weeks. Indications for delivery in these 5 women included worsening maternal medical disease, nonreassuring fetal testing, and spontaneous preterm labor. Six of 8 women with viable fetuses underwent cesarean delivery. These 6 infants were born in good condition without thrombocytopenia. Of the remaining 2 infants delivered vaginally, one was healthy at 35 weeks and the other was stillborn. CONCLUSION: Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome complicating pregnancy is associated with high maternal mortality and long-term morbidity. Preterm delivery and intrauterine fetal death are frequent complications of these pregnancies. Improved survival after this disorder has been attributed to aggressive treatment with plasma transfusion or plasmapheresis.

Sacroiliitis associated with pyelonephritis in pregnancy.

BACKGROUND: Sacroiliitis is a rare infection and an unusual cause of back pain during pregnancy. Because pregnancy and infections commonly associated with pregnancy are risk factors, this diagnosis should be considered in the gravida with sacroiliac pain. CASE: A 17-year-old woman at 24 weeks' gestation, with a history of illicit drug use, presented to a local emergency room with back and buttock pain. Bacteriuria and pyuria were diagnosed, and cefazolin was initiated. Blood cultures grew Staphylococcus aureus and Escherichia coli. Despite prolonged antibiotic therapy for possible endocarditis, she had persistent debilitating lower back and buttock pain. Radiographic studies detected sacroiliitis, and broadened antibiotic therapy effected cure. CONCLUSION: When sacroiliitis is suspected, diagnostic imaging with either computed axial tomography, or, preferably, magnetic resonance imaging may be helpful. Antibiotic therapy should be tailored to the specific organism involved and continued for 3-6 weeks.

The effects of centrally administered adenosine on fetal sheep heart rate accelerations.

OBJECTIVE: We examined the effect of administering a long-acting adenosine analog, L-2-N6-(phenylisopropyl) adenosine, into the cerebrospinal fluid of the fourth ventricle on fetal sheep heart rate accelerations. STUDY DESIGN: Pregnant ewes between 123 and 130 days' gestation were anesthetized, and the fetal head was exteriorized. Catheters were placed in the fourth cerebral ventricle through the foramen magnum and in the brachial artery to record fetal heart rate. Studies were performed in unanesthetized fetuses 4 to 7 days after surgery. Accelerations were defined as a 10 beats/min rise in heart rate for at least 5 seconds. RESULTS: The mean number of accelerations before administration of L-2-N6- (phenylisopropyl) adenosine was 3.9 +/- 0.7 (mean +/- SE) per 10-minute epoch, decreasing to 2.0 +/- 0.7 and 1.4 +/- 0.8 after instillation of 0.2 microgram and 0.5 micrograms of L-2-N6-(phenylisopropyl) adenosine, respectively (p < 0.05). Increasing the L-2-N6-(phenylisopropyl) adenosine dose to 10.0 micrograms resulted in loss of heart rate accelerations. Accelerations were not reduced when theophylline, an adenosine receptor blocker, was given before L-2-N6-(phenylisopropyl) adenosine. CONCLUSION: Increasing amounts of a centrally administered adenosine analog progressively decreased the number of fetal sheep heart rate accelerations, most probably by suppression of brainstem sympathetic outflow.

The tetracyclines.

The tetracyclines are inexpensive drugs that are of primary value in treating nonpregnant women who have acute urethral syndrome or endocervicitis due to Chlamydia trachomatis. They are contraindicated in pregnancy because they are injurious to fetal teeth and bone.