Biomedical subjects

W F O'Brien

Publications and source records attributed to W F O'Brien.

At least 55 records · Page 3Linked to original sources

PubMed1991

Cervical cerclage in early pregnancy.

A retrospective review of 33 patients who underwent transvaginal cervical cerclage for the treatment of an incompetent cervix from June 1984 through July 1987 was conducted. A total of 38 transvaginal cerclages were placed. For the purposes of comparison, the patients were divided into three groups according to gestational age at the time of cerclage: group 1 less than or equal to 13 weeks; group 2 greater than 13 weeks, but less than 18 weeks; group 3 greater than or equal to 18 weeks. There was no difference among groups in mean age, gravidity, history of diethylstilbestrol exposure (DES), prior pregnancy loss at or before 20 weeks, or prior dilation and curettage procedure. There were 24 modified McDonald and 14 modified Shrodkar procedures performed. The mean gestational age of cerclage placement in group 1 was earlier than in group 2 and group 3 by 3.5 and 10.5 weeks, respectively. There were no major surgical complications in any of the three groups. The overall incidence of preterm labor and preterm birth were 48.6% and 37.8%, respectively. Analysis of variance demonstrated a trend toward differences in the incidence of preterm labor, preterm birth, and estimated gestational age at delivery, with the earlier group favored. None of these, however, reached the level of statistical significance. Estimated blood loss, obstetric complications, mean birthweight, and mean gestational age at delivery were not statistically different for the three study groups. The above data are discussed and support given for the safety and efficacy of cervical cerclage placement in early pregnancy when compared with the more standard recommendations of placement at from 14 to 17 weeks' gestational age.

Adult↗

PubMed1991

A randomized comparison of assisted vaginal delivery by obstetric forceps and polyethylene vacuum cup.

The assisted vaginal delivery methods of rigid obstetric forceps and polyethylene vacuum cup extraction were compared in a prospective, randomized study. The 99 women studied had all completed 35 full weeks' gestation, required attempted assisted vaginal delivery, and were randomly assigned to either attempted forceps or vacuum-assisted delivery. All presentations were cephalic, with stations ranging from +1 to +4. Neonates were evaluated at 24 hours by neonatal staff. The infants underwent intracranial ultrasound screening during the first 24 hours of life and ophthalmologic examination within 48 hours. Vaginal delivery was successful with the intended method in 83% of vacuum-assisted deliveries and in 78% of forceps deliveries (not statistically significant). Neonatal retinal hemorrhage was found in 17 and 38% (P less than .043) of the randomized forceps and vacuum deliveries, respectively. No intraventricular hemorrhage was found. Apart from associations between vacuum-assisted delivery and mild hyperbilirubinemia and neonatal retinal hemorrhage (of uncertain clinical significance), and between assisted forceps delivery and an increased potential for facial injury, neonatal outcomes did not differ significantly. Maternal outcomes also did not differ significantly. No significant differences in safety or efficacy were found between polyethylene cup vacuum extraction and rigid obstetric forceps-assisted vaginal delivery in this population of predominantly low-pelvic assisted deliveries. Patients delivered by sequential use of forceps after vacuum or by vacuum after failed forceps application did not suffer significantly increased morbidity relative to those delivered by forceps or vacuum alone. Use of alternate or sequential methods allowed an overall cesarean rate of 3% in this population.

Acid-Base Equilibrium↗

PubMed1991

The effect of magnesium sulfate on the biophysical profile of normal term fetuses.

Forty term pregnant women with singleton breech gestations admitted for external cephalic version underwent biophysical profile testing before any fluid infusion or medication. After magnesium sulfate had been infused for contraction prophylaxis, the maternal serum magnesium level was measured and a second biophysical profile was performed. The mean (+/- SD) serum magnesium was 5.1 +/- 1.0 mg/dL. The biophysical profile score decreased significantly, reflecting a decrease in fetal breathing activity. In patients with therapeutic maternal serum magnesium levels, loss of any component of the biophysical profile other than respiration cannot be attributed to the elevation in magnesium concentration.

Adult↗

PubMed1991

Sequential outpatient application of intravaginal prostaglandin E2 gel in the management of postdates pregnancies.

A randomized blinded investigation was undertaken to determine the efficacy and safety of sequentially applied intravaginal prostaglandin E2 (PGE2) gel for accelerating cervical ripening in an outpatient setting in low-risk prolonged pregnancies. Fifty women with uncomplicated pregnancies at or beyond 41 weeks' gestation and Bishop scores below 9 received twice-weekly outpatient administration of gel containing 2.0 mg of PGE2 or placebo. Thirty nulliparas and 20 multiparas were enrolled. The PGE2 gel failed to improve cervical ripening over placebo, as judged by Bishop scores. There was no difference between the groups in gestational age on admission to the labor and delivery suite, number of gel applications, requirement for oxytocin, incidence of cesarean delivery, or neonatal outcome. Only two patients (4%) experienced regular uterine contractions after gel insertion; these subsided spontaneously in both. None of the subjects experienced labor, tetanic contractions, evidence of fetal distress, or any other side effects related to gel insertion. We conclude that PGE2 gel in this dosage may be used safely in an outpatient setting, but more frequent application or earlier initiation may be required to produce a clinical effect.

Administration, Intravaginal↗

PubMed1991

A randomized comparison of umbilical vein and intravenous oxytocin during the puerperium.

Oxytocin was administered in a randomized fashion via either the umbilical or maternal intravenous route. Women who received intraumbilical oxytocin had significantly greater calculated blood loss compared with those who received peripheral administration (P = .01). This greater blood loss was confirmed by a decrease in hematocrit and hemoglobin concentrations after delivery. There was no difference between the groups in the length of the third stage of labor. The incidence of fetomaternal transfusion was higher in the intraumbilical group (P = .07). We conclude that intraumbilical oxytocin is no more beneficial than peripheral administration.

Adult↗

PubMed1990

The value of early third-trimester maternal serum alpha-fetoprotein determination.

The value of determination of maternal serum of alpha-fetoprotein (MSAFP) concentration in the second trimester is well established. In addition to open neural tube defects, pregnancies associated with elevated second-trimester MSAFP have been shown to be at increased risk for a variety of problems, including low birth weight, preterm delivery, and pregnancy-induced hypertension (PIH). We evaluated the potential usefulness of MSAFP in the early third trimester. MSAFP concentration was determined in over 200 women at the time of glucose screening. Results were analysed with regard to gestational age at sampling, maternal weight, race, diabetes, and presence of twins. MSAFP was twice as high in twin gestation, but not affected by race or the presence of diabetes. In contrast to levels in early gestation, third-trimester MSAFP does not appear to be predictive of preterm delivery, low birth weight, or PIH.

Female↗

PubMed1990

Potential prenatal predictions of Down syndrome: a statistical analysis.

To determine the feasibility of combining several screening tests for the prenatal detection of Down syndrome, we evaluated the potential relationship among three proposed predictors. We determined the concentration of chorionic gonadotropin in frozen serum samples from women of known maternal age and weight, fetal biparietal diameter, and femur length, and alpha-fetoprotein concentration. When corrected for gestational age and maternal weight, the potential predictors were independent, except for a slight correlation (r = 0.10) between maternal serum alpha-fetoprotein and maternal serum human chorionic gonadotropin. Both maternal serum human chorionic gonadotropin and biparietal diameter/femur length demonstrated an approximately log-normal distribution similar to maternal serum alpha-fetoprotein. Therefore it is scientifically sound to use any or all of these variables in combination for the identification of pregnancies at increased risk for Down syndrome.

Body Weight↗

PubMed1990

Amniotic fluid alpha 1-antitrypsin concentration in premature rupture of the membranes.

Premature rupture of the membranes is probably a result of a loss in amniotic membrane collagen. A recent report that the concentration of alpha 1-antitrypsin was decreased in patients with premature rupture of the membranes suggested a generalized defect in such pregnancies. In this study we compared the concentration of alpha 1-antitrypsin in samples from pregnancies with premature rupture of the membranes and from pregnancies with preterm labor at similar gestational age. No difference in alpha 1-antitrypsin concentration was noted between these groups or between samples with or without intrauterine infection. These results support a localized inflammation and necrosis of the membranes at the site of rupture.

Amniotic Fluid↗

PubMed1990

Effect of maternal-fetal movement on concentration of cells obtained at genetic amniocentesis.

The number of viable amniotic fluid cells in the aliquot obtained at amniocentesis is an important determinant of the success of subsequent cell culture. However, cell concentration and viability are highly variable, even in samples of equivalent gestational age. We studied the effect of prescribed maternal position change or spontaneous fetal movement on the concentration, viability, and subsequent harvest time of amniotic fluid cells removed at genetic amniocentesis. Samples from 108 patients at 15 to 22 weeks' gestation were evaluated. We did not find a relationship between this type of maternal or fetal movement and the retrieval of amniotic fluid cells.

Adult↗

PubMed1990

The effect of magnesium sulfate infusion on systemic and renal prostacyclin production.

Recent in vitro studies have suggested that magnesium sulfate (MgSO4) infusions may increase prostacyclin production. We studied the effect of MgSO4 infusion on prostacyclin (PGI2) metabolite excretion in women with either pregnancy induced hypertension or preterm labor. Excretion of renal and systemic metabolites of PGI2 was measured prior to and following the start of MgSO4 infusion in the two groups. An increased in renal PGI2 metabolite preterm labor excretion was noted in the hypertension group but no change was noted in systemic PGI2 excretion in either group. These data fail to support a generalized, short term increase in endothelial cell PGI2 production as the basis for the beneficial effect of MgSO4.

Adult↗

PubMed1990

Predicting preeclampsia.

Recent studies suggest that drugs affecting prostacyclin and thromboxane production may be able to affect the development of preeclampsia. In order to use these agents effectively, we must be able to select properly women at high risk. This review evaluates a number of historic and physical factors and laboratory tests that may aid in the prediction of preeclampsia. Family history, parity, and the roll-over test are currently the most efficient methods that are widely available. Two relatively new laboratory tests, plasma fibronectin concentration and urinary calcium/creatinine ratio, hold the greatest promise for the near future.

Angiotensin II↗

PubMed1990

Acute pyelonephritis in pregnancy: a prospective study of oral versus intravenous antibiotic therapy.

Ninety pregnant women admitted to the high-risk pregnancy unit with a diagnosis of acute pyelonephritis were randomized to receive either oral (cephalexin 500 mg every 6 hours) or intravenous (IV) (cephalothin 1 g every 6 hours) antibiotic therapy. All patients were initially hydrated with 1 L of normal saline IV over 4 hours. Neither parenteral analgesics nor antiemetics were used. Bacteremia was noted in 13 (14.4%) of the 90 patients and mandated IV therapy. There was no difference between the oral and IV groups concerning predefined criteria for successful therapy (91.4 versus 92.9% successful therapy, respectively). No characteristic available at presentation predicted bacteremia or ultimate failure of therapy. Two patients (2.2%) experienced significant complications. These data suggest that in nonbacteremic patients, oral antibiotics are both safe and effective for the treatment of acute pyelonephritis in pregnancy.

Acute Disease↗

PubMed1989

The association between apolipoprotein A-I and prostacyclin binding in human serum.

The stability of Prostacyclin in human blood is dependent upon binding to circulating proteins. Although this binding has been considered to be primarily due to albumin, a recent report has suggested that apolipoprotein A-I is responsible. We compared prostacyclin binding to the concentration of albumin and apolipoprotein A-I in several groups of sera with known differences in the ability to bind prostacyclin. Our results indicate a strong correlation with albumin concentration but no correlation between binding and the concentration of apolipoprotein A-I. It appears that in the human circulation albumin concentration is the most important determinant of prostacyclin binding.

Apolipoprotein A-I↗

PubMed1989

Influence of albumin and non-esterified fatty acids on serum prostacyclin binding in pregnancy.

We investigated the etiology of the previously documented decrease in serum prostocyclin binding during pregnancy. Addition of albumin to the serum of pregnant women failed to raise binding to non-pregnant levels. Pregnancy serum bound significantly more prostacyclin following the removal of non-esterified fatty acids and the addition of fatty acid free albumin resulted in a rise in binding to non-pregnant levels. We conclude that serum protein prostacyclin binding is affected by both albumin concentration and non-esterified fatty acids.

Blood Proteins↗

PubMed1989

Fetal lung maturation: the combined use of corticosteroids and thyrotropin-releasing hormone.

The purpose of this randomized study was to evaluate whether the combined use of corticosteroids and thyrotropin-releasing hormone would enhance fetal lung maturation to a greater degree than would corticosteroids alone. The study was restricted to patients under 34 weeks' gestation with a lecithin/sphingomyelin (L/S) ratio less than 2.0. The patients were randomized into a study group receiving intravenous thyrotropin-releasing hormone along with intramuscular corticosteroids over 48 hours and a control group receiving only corticosteroids. Patients undelivered 1 week after the onset of therapy underwent a repeat amniocentesis to document changes in the L/S ratio. In those patients delivering within 1 week of therapy, the neonatal clinical course was established by two investigators blinded to the antenatal therapy. Compared with the control group, the group receiving antenatal corticosteroids plus thyrotropin-releasing hormone showed a greater post-therapy increase in L/S ratio, fewer respirator days, and a lower incidence of bronchopulmonary dysplasia. The results of this study suggest that the combined use of corticosteroids and thyrotropin-releasing hormone results in enhanced fetal pulmonic maturation superior to that achieved with corticosteroids alone.

Betamethasone↗

PubMed1989

Serum prostacyclin binding and half-life in normal and hypertensive pregnant women.

The effective half-life of prostacyclin in human serum is highly dependent on binding to serum proteins. Abnormalities in prostacyclin binding appear to be important in some patients with thrombotic thrombocytopenic purpura. We investigated prostacyclin binding and half-life in normotensive and hypertensive pregnant women and in nonpregnant controls. Pregnancy was associated with a decrease in serum prostacyclin binding and a shorter prostacyclin half-life. This decrease was even greater in women with hypertensive disorders. The decrease in prostacyclin half-life in hypertensive disorders may play an important role in the pathogenesis of these disorders. Measurement of both production and metabolism, however, will be required to adequately assess the role of prostacyclin in normal and abnormal gestation.

Adult↗

PubMed1989

Efficacy and safety of indomethacin versus ritodrine in the management of preterm labor: a randomized study.

One hundred six patients in preterm labor with intact amniotic membranes and gestational age less than or equal to 32 weeks were randomized to receive either ritodrine hydrochloride or a 48-hour course of indomethacin for tocolysis. The relative efficacy, maternal and neonatal safety, and costs were evaluated to determine which may be the more appropriate first-line pharmacologic agent used to manage preterm labor. Fifty-four patients and 52 patients were randomized to receive ritodrine hydrochloride or indomethacin, respectively. Ritodrine hydrochloride and indomethacin were equally effective in inhibiting uterine contractions and delaying delivery. Delivery was delayed for at least 48 hours in 83 and 94%, and for at least 7 days in 70 and 75% of patients receiving ritodrine or indomethacin, respectively. Tocolysis with indomethacin was associated with no maternal side effects, whereas tocolysis with ritodrine hydrochloride was associated with a 24% incidence of serious cardiovascular and metabolic adverse effects prompting discontinuation of the drug. There were no differences in outcome between the infants exposed to indomethacin versus ritodrine hydrochloride when delivered either remote from therapy or during therapy, except for a statistically higher serum glucose in the infants exposed to ritodrine hydrochloride when delivered during tocolytic therapy. There were no cases of premature closure of the ductus arteriosus or pulmonary hypertension. Tocolysis with indomethacin was 17 times less costly than tocolysis with ritodrine hydrochloride. For gestations less than or equal to 32 weeks complicated by preterm labor, indomethacin may be an appropriate alternative as a first-line tocolytic agent.

Adult↗

PubMed1989

Use of ampicillin and corticosteroids in premature rupture of membranes: a randomized study.

A randomized study was conducted to investigate the effects of antenatal corticosteroids and ampicillin in the management of preterm pregnancies under 34 weeks complicated by premature rupture of membranes. Patients with documented lecithin/sphingomyelin (L/S) ratios of less than 2.0 and a singleton gestation were eligible to participate in the study. One hundred sixty-five patients qualified and were randomized, using sealed envelopes, to four study groups. All patients were followed expectantly. Group I (41 patients) received neither ampicillin nor corticosteroids. Group II (43 patients) received 24 mg of antenatal betamethasone. Group III (37 patients) received 2 g of intravenous ampicillin every 6 hours, with discontinuation of antibiotic therapy if cultures were negative for pathogenic bacteria. Group IV (44 patients) received both corticosteroids and ampicillin as described for groups II and III, respectively. Compared with patients not receiving corticosteroids, those administered antenatal corticosteroids experienced a reduction in the incidences of respiratory distress syndrome (53 versus 26%), bronchopulmonary dysplasia (23 versus 9%), severe grades of intracranial hemorrhage (15 versus 3%), and patent ductus arteriosus (18 versus 6%), with no difference in the incidence of maternal or neonatal infection. Compared with patients not receiving antenatal antibiotics, the group of patients treated with ampicillin on admission had a lower incidence of clinical chorioamnionitis (4 versus 26%) and neonatal sepsis (5 versus 10%). This reduction in infectious morbidity by antenatal ampicillin was restricted to those patients (28.4% of the study population) colonized with group B streptococci.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗