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Biomedical subjects

R K Laros

Publications and source records attributed to R K Laros.

At least 37 records · Page 2Linked to original sources
PubMed1992

Maternal and neonatal outcomes after oxytocin augmentation in patients undergoing a trial of labor after prior cesarean delivery.

OBJECTIVE: To study the safety of oxytocin augmentation in patients having abnormal labors after a prior cesarean delivery. METHODS: We retrospectively analyzed a case series of women undergoing a trial of labor after a previous cesarean delivery from the University of California San Francisco perinatal data base. Women whose labors were augmented with oxytocin were compared to women with labor abnormalities managed without the use of oxytocin. A wide range of maternal and neonatal outcomes was compared. Only vertex singleton term deliveries were studied. RESULTS: From 1975-1990 there were 504 trials of labor, of which 185 (37%) had labor abnormalities; 62 of these 185 (34%) were augmented with oxytocin. Fifty-eight percent of the trials of labor ended in vaginal delivery. In patients since 1982, 73% delivered vaginally. Forty-six (74%) of augmented patients delivered vaginally. There were no maternal deaths, uterine ruptures, or hysterectomies. Estimated blood loss was slightly greater among augmented patients after controlling for mode of delivery (P < .05), but only by 50-100 mL on average. There was no difference in the need for maternal transfusion. Fetal trauma and fetal scalp blood sampling occurred more frequently (P < .05) in the augmented labors, but only in the subgroup delivered by cesarean. No increased risk was demonstrated by a comparison between patients receiving oxytocin and epidural anesthesia and patients with labor abnormalities receiving neither. CONCLUSION: Retrospective analysis supports the use of oxytocin and epidural anesthesia to augment abnormal trials of labor after prior cesarean.

Anesthesia, Epidural↗
PubMed1991

Outcome of very-low-birth-weight infants exposed to beta-sympathomimetics in utero.

In this study we examined neonatal and early childhood outcomes after intrauterine exposure to beta-sympathomimetic agents on infants with birth weights less than or equal to 1500 gm. The hospital courses and anthropomorphic, developmental, and neurologic development of 201 infants exposed to one or more beta-sympathomimetic agents (isoxsuprine, 33; ritodrine, 70; terbutaline, 43; combination, 55) were analyzed and compared with those of 130 control infants of similar birth weight. One hundred and seventy-seven infants had follow-up to 1 year of age, 101 to age 3, and 58 to age 4. When treatments consisting of a single beta-sympathomimetic or no treatment were compared, there were no statistically significant overall differences found in growth and development or in most of the short-term measures of infant well-being. However, significant overall differences with no evidence of confounding by time-related effects were found for the following; mortality, none greater than terbutaline; maximum positive inspiratory pressure when respiratory distress syndrome was present, none greater than terbutaline; neonatal trauma, terbutaline greater than ritodrine. Other differences were found in conjunction with evidence of time-related confounding, or within specific time intervals. It should be noted that these differences are not necessarily due to effects of the different treatments, as the data are observational.

Female↗
PubMed1991

Obstetric complications with GDM. Effects of maternal weight.

Obstetric complications recorded prospectively were assessed retrospectively in 150 women with gestational diabetes mellitus (GDM) and 305 control subjects matched for age, parity, and ethnicity. Intensive diet therapy and self-monitoring of capillary blood glucose were used to obtain postprandial euglycemia; 22% of GDM subjects required insulin. GDM and control subjects were grouped by body mass index to detect any influence of maternal prepregnancy weight on outcome. Polyhydramnios, preterm labor, and pyelonephritis were not more frequent in GDM, but hypertension without proteinuria (7.3 vs. 3.3%) and preeclampsia (8 vs. 3.9%) were more frequent in GDM. The frequency of hypertensive complications in GDM was not totally attributable to being overweight. Abnormalities of labor, birth trauma, and fetal macrosomia were not more common in GDM; 6.7% of the infants of mothers with GDM weighed greater than 4200 g at birth compared with 3.6% of control infants (NS), and 10% were large for gestational age and sex compared with 6.6% of control infants (NS). Despite this, cesarean delivery was more common in GDM (35.3 vs. 22%, P less than 0.01), mostly due to significantly more cesarean births without labor.

Birth Weight↗
PubMed1991

Maternal hydration increases amniotic fluid index.

Although adequate amniotic fluid (AF) volume is considered an important aspect of fetal well-being, the etiology of decreased AF volume is not well understood. A randomized blinded trial was designed to examine our hypothesis that maternal hydration would increase the AF index in women with low AF indexes. Women seen in our testing centers were randomized into control or hydration groups. The control group was instructed to drink their normal amount of fluid; the hydration group was instructed to drink 2 L of water, in addition to their usual amount of fluid, 2-4 hours before the post-treatment AF index. The women returned for the post-treatment AF index the same or following day. The mean post-treatment AF index was significantly greater in the hydration group (6.3 versus 5.1; P less than .01), as was the mean change in AF index (post-treatment AF index--pre-treatment AF index: 1.5 versus 0.31; P less than .01). These findings suggest that maternal oral hydration increases AF volume in women with decreased fluid levels.

Amniotic Fluid↗
PubMed1991

Factors associated with postpartum hemorrhage with vaginal birth.

A case-control study was performed to study risk factors for postpartum hemorrhage. Cases of hemorrhage were defined by a hematocrit decrease of 10 points or more between admission and post-delivery or by the need for red-cell transfusion. Patients with antenatal bleeding were excluded. Among 9598 vaginal deliveries, postpartum hemorrhage occurred in 374 cases (3.9%). Three controls were matched to each case and multiple logistic regression was used to control for covariance among predictor variables. Factors having a significant association with hemorrhage were prolonged third stage of labor (adjusted odds ratio 7.56), preeclampsia (odds ratio 5.02), mediolateral episiotomy (4.67), previous postpartum hemorrhage (3.55), twins (3.31), arrest of descent (2.91), soft-tissue lacerations (2.05), augmented labor (1.66), forceps or vacuum delivery (1.66), Asian (1.73) or Hispanic (1.66) ethnicity, midline episiotomy (1.58), and nulliparity (1.45). These data may help predict postpartum hemorrhage and may be useful in counseling patients about the advisability of home delivery, intravenous access in labor, or autologous blood donation.

Case-Control Studies↗
PubMed1991

Factors associated with hemorrhage in cesarean deliveries.

A case-control study was performed to study risk factors for hemorrhage in cesarean deliveries. Hemorrhage was defined by a pre- to post-delivery hematocrit decrease of 10 points or more or by the need for red-cell transfusion. Patients with antenatal bleeding were excluded. Among 3052 cesarean deliveries, hemorrhage occurred in 196 cases (6.4%). Three controls were matched to each case and multiple logistic regression was used to control for covariance among predictor variables. Factors having a significant association with hemorrhage were: general anesthesia (adjusted odds ratio 2.94), amnionitis (odds ratio 2.69), preeclampsia (2.18), protracted active phase of labor (2.40), second-stage arrest (1.90), and Hispanic ethnicity (1.82). After adjustment for these variables, a classic uterine incision had a small but significant association (odds ratio 1.06) with hemorrhage. Previous cesarean, parity, gestational age, and several other factors had no association with hemorrhage. These data allow one to anticipate hemorrhage in patients at risk and may be useful in planning appropriate use of blood bank resources, including antepartum autologous blood donation.

Blood Loss, Surgical↗
PubMed1991

Prolonged third stage of labor: morbidity and risk factors.

Although retained placenta is a major cause of postpartum hemorrhage, there is no general agreement regarding when manual placental extraction is indicated to prevent hemorrhage. We sought to determine the following: 1) what duration of the third stage of labor is abnormal, 2) what duration is associated with complications, and 3) what antecedent conditions are associated with prolonged third stage. We studied 12,979 consecutive, singleton vaginal deliveries over an 11-year period. Third-stage duration had a log-normal distribution, with a geometric mean of 6.8 minutes, a median of 6 minutes, and an interquartile range of 4-10 minutes. A third stage of 30 minutes or longer occurred in 3.3% of the deliveries. The incidence of postpartum hemorrhage, transfusion, and D&C remained constant in third stages less than 30 minutes, then rose progressively, reaching a plateau at 75 minutes. The increase in these complications after 30 minutes was observed with both spontaneously delivered and manually extracted placentas. In a logistic regression analysis, factors significantly associated with prolonged third stage included: preterm delivery (odds ratio 3.81), delivery in a labor bed (odds ratio 2.17), preeclampsia (odds ratio 1.76), augmented labor (odds ratio 1.47), and nulliparity (odds ratio 1.45). Because there was no increase in hemorrhage until the third stage exceeded 30 minutes, we suggest that in the absence of bleeding, manual placental extraction is not indicated until 30 minutes have elapsed.

Female↗
PubMed1990

Neonatal and maternal outcome in low-pelvic and midpelvic operative deliveries.

A retrospective analysis of low-pelvic and midpelvic operative deliveries (according to the new definitions by the American College of Obstetricians and Gynecologists, 1989) matched with cesarean section deliveries of similar station was undertaken. In all vaginally delivered groups there was significantly decreased maternal morbidity, maternal hospital stay, and estimated blood loss. In the midpelvic deliveries, there was a significant increase in the frequency of neonatal resuscitation and an increase in base deficit for the umbilical artery. In both the midforceps and low-forceps groups, there was a significant increase of neonates with cord arterial pH less than 7.10, and an increase of base deficit, even when cases of fetal distress were eliminated. The midforceps group also had an increased rate of admission to the intensive care nursery and an increase in the risk of significant birth trauma. In considering a midforceps or midvacuum operative delivery, the potential associated risks to the neonate must be balanced against the benefits to the mother.

Birth Injuries↗
PubMed1990

Risk factors for third-degree and fourth-degree perineal lacerations in forceps and vacuum deliveries.

Third- and fourth-degree perineal lacerations occur frequently during operative vaginal deliveries. To identify risk factors for lacerations, 2832 consecutive forceps and vacuum extraction deliveries were analyzed. Third- and fourth-degree lacerations occurred in 30% of deliveries. Multiple logistic regression was used to control for intercorrelation between potential risk factors. Factors associated with increased risk for third- and fourth-degree lacerations were midline episiotomy, nulliparity, second-stage arrest, occipitoposterior position, low or mid station, use of forceps instead of vacuum, use of local anesthesia, and Asian race. When these factors were controlled, there was no effect of birth weight, faculty versus resident operator, gestational age, abnormalities of first-stage labor, or several other factors. Prevention of perineal lacerations requires that the operator identify the patient at risk. Possible options for management of high-risk patients include use of mediolateral episiotomy or no episiotomy, use of vacuum extraction instead of forceps, and use of conduction anesthesia.

Anesthesia, Obstetrical↗
PubMed1990

Müllerian duct anomalies: MR imaging evaluation.

Twenty-nine patients underwent magnetic resonance (MR) imaging for investigation of müllerian duct anomalies (MDAs). The anomalies evaluated were uterine agenesis (n = 2), uterine hypoplasia (n = 5), unicornuate uterus (n = 5), uterus didelphys (n = 5), bicornuate uterus (n = 10), and septate uterus (n = 2). The MR imaging interpretation was correlated with results of laparotomy (n = 18), hysterosalpingography (HSG) (n = 5), laparoscopy (n = 2), hysteroscopy (n = 1), HSG and laparotomy (n = 2), and HSG and laparoscopy (n = 1). MR imaging enabled correct classification of the anomaly in each patient and identification of coincidental gynecologic disease in 10 patients (34%). MR imaging results influenced clinical treatment in six (24%) of 25 patients referred prospectively. Of particular value was the ability to characterize septal tissue (myometrium versus fibrous tissue), identify the patients in whom the septum of bicornuate uteri had both fibrous and myometrial components, and establish that suspected adnexal lesions were actually components of obstructed MDAs.

Adult↗
PubMed1989

Evaluation of a risk-scoring system for prediction of preterm labor.

A scoring system was used prospectively to screen 7329 patients for risk of preterm labor over a 6-year period. When 15.8% of patients (1156 of 7329) were scored as high risk, sensitivity was 42.4% (multiparas, 55.2%, nulliparas, 29.8%) and positive predictive value was 22.8%. The incidence of preterm labor increased with increasing risk score; gestational age at delivery was negatively correlated with risk score. Analysis of individual factors revealed that more than half were not of predictive value in the population under investigation. A simplification of the system, defining 12 of the factors as major (high risk) and six as minor (2 or more indicates high risk) yielded a high risk group of 14.1%, sensitivity of 41.0%, and positive predictive value of 24.6%. Thus, although risk scoring does predict a substantial proportion of patients with preterm labor, its sensitivity is less than ideal. No advantage was gained with a larger and more complex system. Planning for preterm birth prevention programs should include recognition of the limitations of risk scoring, consideration of simplified systems, and investigation of additional biochemical or biophysical screening methods.

Female↗
PubMed1989

Characteristics of normal labor.

The length of the first and second stages of labor was evaluated in 6991 women with singleton gestations at 37-42 weeks with vertex presentation. All patients delivered spontaneously without the use of oxytocin. Four study groups were created based on parity and whether conduction anesthesia was used. The mean lengths and limits (95th percentile) for the first stage of labor, respectively, were as follows: nulliparas: no anesthesia--8.1 and 16.6 hours, conduction anesthesia--10.2 and 19.0 hours; multiparas: no anesthesia--5.7 and 12.5 hours, conduction anesthesia--7.4 and 14.9 hours. Similar data for the second stage were as follows: nulliparas: no anesthesia--54 and 132 minutes, conduction anesthesia--79 and 185 minutes; multiparas: no anesthesia--19 and 61 minutes, conduction anesthesia--45 and 131 minutes. These statistical parameters are useful for defining when a labor becomes abnormal and intervention should be considered.

Anesthesia, Conduction↗
PubMed1988

Maternal brain death during pregnancy. Medical and ethical issues.

We present in detail a case of a 27-year-old primigravida who was maintained in a brain-dead state for nine weeks. An apparently normal and healthy male infant weighing 1440 g was delivered. The newborn did well and was found to be growing and developing normally at 18 months of age. Although the technical aspects of prolonged life support are demanding and the economic costs are very high (+217,784), there are ample ethical arguments justifying the separation of brain death and somatic death and the maintenance of the brain-dead mother so that her unborn fetus can develop and mature.

Adult↗
PubMed1988

Management of twin pregnancy: the vaginal route is still safe.

To investigate the effect of method of delivery on the outcome of twin pregnancies, we reviewed all deliveries at our institution over the 10 years from 1976 to 1985. Two hundred six pairs were delivered, with a mean gestational age of 34 weeks (range 20 to 43 weeks) and a mean weight of 2116 gm (range 220 to 3800 gm). The mean gestational age at diagnosis of the twin pregnancy was 23 weeks. Nineteen (4.6%) infants were stillborn, and 36 (8.7%) died in the neonatal period. Cesarean section was used to deliver both twins in 66 cases. The method of delivery for the remaining 142 cases was vaginal-vertex, 85 (61%), vaginal-breech, 40 (29%), cesarean section, 13 (9%), and version and extraction, 2 (1%). The four most common indications for cesarean section for both twins were previous cesarean section, breech presentation, abnormal labor, and fetal distress. The indications for the 13 cesarean sections after vaginal delivery of twin A were fetal distress, cord prolapse, high presenting part, and footling breech. The impact of the method of delivery was investigated by comparing outcome variables between twin pairs. No significant differences were noted for perinatal mortality, need for resuscitation, duration of newborn hospital stay, and trauma. There were significant differences in the 1- and 5-minute Apgar scores in the vaginal delivery group. These differences were clinically minor, tending toward mild acidemia, and were unaffected by route or method of delivery.

Delivery, Obstetric↗
PubMed1988

Factors affecting prenatal sonographic estimation of weight in extremely low birthweight infants.

Because critical management decisions are based on sonographic estimation of fetal weight in fetuses less than 1000 g, we sought to evaluate the accuracy of birthweight prediction in this range and to identify factors affecting this accuracy. Fetal weight was estimated using several published methods in 53 fetuses with birthweights less than 1000 g. Standard deviations greater than 12.3% indicate more random error in the sonographic weight prediction than has been reported in higher weight groups. No statistically significant differences were found between patient groups with decreased, normal, or increased amniotic fluid volume or portable examination. There was a trend toward lower mean deviation (2.9 vs 6.0%) and standard deviation (8.9 vs. 15.0%) in studies with scan quality judged "good" compared with "poor" based on ability to visualize anatomic landmarks.

Amniotic Fluid↗
PubMed1988

California North Coast Preterm Birth Prevention project.

A demonstration project aimed at reducing the incidence of preterm birth in a rural population of Northern California was conducted using risk assessment, patient education, and education for providers as interventions. We compared 1914 preintervention deliveries with 7382 births during the intervention period. Although the percentage of preterm labor patients eligible for tocolysis was 34% greater during the intervention period than during the preintervention period, and the percentage of preterm labor patients who achieved term gestation was 53% greater in the intervention period, the overall rate of spontaneous preterm delivery in the population did not differ significantly in the two periods.

Birth Rate↗
PubMed1987

Management of term breech presentation.

The management of 716 cases of singleton breech presentation occurring at 37 or more weeks of gestational age is reviewed. Beginning in 1980 a trial of external version was offered if the breech was identified before active labor. Only 433 (61%) breeches were identified before active labor. Of these, 171 (44%) underwent an attempt at external version and 83 (48%) were successful. The 623 cases remaining as breech presentation were stratified into three groups: cesarean section without labor (379), trial of labor with cesarean section (69), and trial of labor with vaginal delivery (175). The criteria for allowing a trial of labor are detailed. Careful review of maternal and fetal variables indicates that a trial of labor in selected patients will result in vaginal delivery in 72% and that this can be achieved without an increase in fetal or maternal mortality or morbidity. Furthermore, successful external version followed by a trial of labor in selected cases is highly cost-effective.

Breech Presentation↗