Sleep patterns in pregnancy: a longitudinal study of polysomnography recordings during pregnancy.

OBJECTIVE: To evaluate the differences in sleep of women throughout pregnancy compared with those of nonpregnant control subjects. STUDY DESIGN: Four pregnant women were studied longitudinally during their pregnancy using inpatient polysomnography. Measurements included electroencephalography, electrocardiography, and continuous-pulse oximetry. Four healthy nonpregnant women matched for age and weight were used as control subjects. The total sleep time was recorded, and percentages of each sleep stage were generated. RESULTS: Qualitative differences in sleep between pregnancy patients and control subjects were evident. Control subjects displayed a normal appearance of slow-wave sleep in stages 3 and 4 (delta sleep). When pregnant patients did display delta sleep, it appeared abnormal secondary to extensive alpha-wave intrusion. Even when including this abnormal delta sleep in a quantitative comparison, the pregnant patients had a significantly shorter percentage of total sleep time in delta sleep (4.9+/-1.9% vs 21.9+/-6.0%, p=0.03). CONCLUSION: Sleep in pregnancy is characterized by loss of normal slow-wave sleep. Thus, sleep stages 3 and 4 are shortened during pregnancy. This sleep alteration is persistent when followed longitudinally during pregnancy.

Home blood pressure monitoring for pregnant patients with hypertension.

OBJECTIVE: To determine whether automated measurement of blood pressure and pulse in a home setting can be easily accomplished by pregnant women with chronic hypertension. STUDY DESIGN: In this prospective investigation, seven women with chronic hypertension complicating pregnancy recorded their blood pressure at home twice a day. These data were offloaded once daily into a computer at a remote site, and a computerized printout of these data was received by the physician. RESULTS: The patients participated in the study for 12.2 +/- 5.8 weeks (range 4 to 18 weeks) and were between 23 and 42 weeks' gestation. Average mean arterial pressure in the home was 102 +/- 10 mm Hg, and average pulse was 81 +/- 11 beats per minute. In the clinic, the values were 112 +/- 13 mm Hg and 90 +/- 30 beats per minute (p < 0.05). Each patient was easily taught how to use the machine. CONCLUSIONS: The home blood pressure monitoring device was easy to use and correlated well with values recorded by health professionals for this limited number of subjects. It was particularly helpful to patients (n = 5) who lived long distances (more than 60 miles) from the clinic and to women who needed adjustments of antihypertensive medication.

Premature rupture of membranes at 34 to 37 weeks' gestation: aggressive versus conservative management.

OBJECTIVE: Our purpose was to compare induction of labor with preterm rupture of membranes between 34 and 37 weeks' gestation with expectant management. STUDY DESIGN: In this prospective investigation 120 gravid women at > or = 34 weeks 0 days and < 36 weeks 6 days of gestation were randomized to receive oxytocin induction (n = 57) or observation (n = 63). RESULTS: Estimated gestational age at rupture of membranes (34.3 +/- 1.4 weeks vs 34.5 +/- 1.4 weeks) and ultrasonographically estimated fetal weight (2230 +/- 321 gm vs 2297 +/- 365 gm) were equivalent between groups (not significant). Chorioamnionitis occurred more often (16% vs 2%, p = 0.007), and maternal hospital stay (5.2 +/- 6.8 days vs 2.6 +/- 1.6 days, p = 0.006) was significantly longer in the control group. Neonatal sepsis was also more common in the observation group (n = 3) than among induction patients (n = 0), but the difference was not statistically significant. CONCLUSION: Aggressive management of preterm premature rupture of the membranes at > or = 34 weeks 0 days of gestation by induction of labor is safe for the infant in our population and avoids maternal-neonatal infectious complications.

Cesarean section for suspected fetal distress. Does the decision-incision time make a difference?

OBJECTIVE: To compare perinatal outcomes in patients at term (37 weeks) in whom the decision-incision time for cesarean delivery was due to suspected fetal distress. STUDY DESIGN: All parturients who underwent cesarean delivery primarily for possible fetal distress during a three-year period were identified retrospectively. Student's t test and the chi 2 test were utilized, and P < .05 was considered significant. A regression analysis of decision-incision time and umbilical arterial pH was performed. RESULTS: From 1991 to 1993, 1.3% (117/9,137) of term laboring patients underwent emergency cesarean delivery for the primary indication of possible fetal distress. In 61 patients (52%) the decision-incision time was 30 minutes, while it exceeded 30 minutes in the remaining 56 women. The two patient groups were similar in maternal demographics, antepartum complications, oxytocin usage, thick meconium, type of abnormal fetal heart rate tracing prompting surgery, use of amnioinfusion (41% vs. 36%), general anesthesia (97% vs. 93%), mean birth weight and Apgar score < 7 at five minutes. Three adverse outcomes were observed more frequently in association with decision-incision time > 30 minutes: (1) lower mean (+/-SD) umbilical arterial pH (7.16 +/- 0.15 vs. 7.26 +/- 0.06, P = .001), (2) pH < 7.00 (8/61 vs. 0/56, P = .005), and (3) admission to the neonatal intensive care unit (P = .008). When the incision was made longer than 30 minutes after the decision, there was no apparent adverse neonatal or infant outcome. CONCLUSION: Although a cesarean decision-incision time < or = 30 minutes is a desirable goal for the fetus possibly in distress, failure to achieve this goal is not associated with a measurable negative impact on newborn outcome.

Neonatal electrolyte response to amnioinfusion with lactated Ringer's solution vs. normal saline. A prospective study.

OBJECTIVE: To determine if amnioinfusion with normal saline vs. lactated Ringer's solution crystalloids causes electrolyte imbalance in the human neonate. STUDY DESIGN: Over two months, all parturients undergoing amnioinfusion in the active phase of labor were prospectively randomized to receive either normal saline (n = 37) or lactated Ringer's solution (n = 30). Maternal electrolytes were obtained prior to amnioinfusion, and neonatal electrolytes were obtained from cord blood samples at the time of delivery. RESULTS: Our results showed the two groups were similar in maternal age, ethnicity, gravidity, parity, gestational age, maternal electrolyte levels prior to amnioinfusion, amount of solution amnioinfused, duration of labor after amnioinfusion, mode of delivery and mean birth weight. The chloride concentrations were nearly identical among neonates who had received normal saline and those who had received lactated Ringer's solution (102 +/- 2.1 SD and 104 +/- 2.4 mmol/L, respectively; P = 1.0). Other electrolytes were likewise not significantly different regardless of the crystalloid infused. CONCLUSION: Unlike the fetal sheep model, amnioinfusion with normal saline is not associated with hyperchloremia in the human neonate.

Prediction of spontaneous preterm birth by fetal fibronectin and uterine activity.

OBJECTIVE: To evaluate the usefulness of fetal fibronectin and home uterine contraction assessment in predicting preterm birth (before 34 weeks) in at-risk asymptomatic women. METHODS: One hundred fifty women were enrolled prospectively; five were lost to follow-up, leaving 145 women available for analysis. Because patients with preterm labor before 34 weeks' gestation most commonly develop this problem after 28 weeks, the period of 26-28 weeks' gestation was selected prospectively as the first window for prediction and study analysis. Eighty-five of 145 asymptomatic women at high risk for preterm birth had both home uterine contraction assessment of 2 hours per day and one or more cervical sampling(s) for fetal fibronectin measurement at 26-28 weeks. A positive home uterine contraction assessment was defined as contractions exceeding two per hour averaged over the 2-week study interval. Positive fetal fibronectin was defined as greater than 50 ng/mL. RESULTS: Fourteen of the 85 women (16.5%) delivered before 34 weeks. Home uterine contraction assessment alone had a sensitivity, specificity, positive predictive value, and negative predictive value for preterm birth of 64, 85, 45, and 92%, respectively; fetal fibronectin alone was associated with values of 43, 89, 43, and 89%, respectively. A positive home uterine contraction assessment was associated with a relative risk (RR) for preterm birth of 5.9% (95% confidence interval [CI] 2.4-14.2), whereas a positive fetal fibronectin demonstrated an RR of 3.8 (95% CI 1.5-9.4). When both assessments were positive, all patients delivered before 34 weeks and there was an RR of 27.0 (95% CI 8.7-84.1) compared with those with both tests being negative. Only two patients with both tests negative delivered before 34 weeks (negative predictive value 96%). CONCLUSION: Both the home uterine contraction assessment and fetal fibronectin accurately predicted preterm birth before 34 weeks. When both tests were combined, the predictive ability improved substantially.

Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion.

OBJECTIVE: Our purpose was to determine the incidence of adverse cardiovascular effects of terbutaline sulfate when administered as a continuous subcutaneous infusion in women with arrested preterm labor. STUDY DESIGN: Over a 6-year period records from 8709 women prescribed this therapy for preterm labor that had previously been arrested with other intravenous tocolytics were reviewed. These women were assessed daily for cardiovascular complaints and tolerance of the medication, while either in the hospital or at the home (by telephone). The main outcomes studied were the occurrence of pulmonary edema, sustained cardiac arrhythmias, chest pain, or myocardial ischemia. Any maternal death regardless of cause was also reviewed. RESULTS: Of the 8709 subjects, 47 (0.54%) had one or more cardiopulmonary problems. Pulmonary edema developed in 28 patients (0.32%) while receiving continuous subcutaneous infusion of terbutaline, 5 at home and 23 in the hospital. Of the total, 17 women were being treated concurrently with large amounts of intravenous fluids and one to three other tocolytic agents. In the 11 remaining subjects, 4 were diagnosed with pregnancy-induced hypertension and/or multiple gestation. Nineteen patients experienced other adverse cardiovascular effects, including electrocardiogram changes, irregular heart rate, chest pain, or shortness of breath. CONCLUSIONS: Continuous terbutaline infusion for women with stabilized preterm labor is associated with much fewer adverse effects than previous literature regarding intravenous beta-adrenergic agonist therapy would suggest.

Treatment for hyperemesis gravidarum in the home: an alternative to hospitalization.

Our objective was to determine whether medical therapy in the home for patients with hyperemesis gravidarum is safe, efficacious, and cost effective compared with hospitalization. In this retrospective, matched control study 50 women with hyperemesis were treated in the home and were matched for gravidity, gestational age, and weight loss from prepregnancy weight with 47 patients who were hospitalized for traditional treatment. Both groups had similar intravenous fluid and medical support until they could tolerate adequate oral intake. Women in the home had 9.7 +/- 8.0 days of intravenous therapy compared with 9.5 +/- 6.2 days in hospitalized patients (not significant). The mean percent of weight loss at initiation of therapy was similar in both groups (4.6% +/- 5.7% vs 4.5% +/- 6.1%, not significant). The mean weight change during therapy in the home group was + 1.0 +/- 4.3 pounds compared with +1.2 +/- 8.6 pounds in the hospitalized group (not significant). The only complication was infiltration of the intravenous site, the occurrence of which was similar in the two groups (40% vs 57%, not significant). At discontinuation of therapy 90% of the home patients no longer required any supportive therapy; 10% (n = 5) required hospitalization because of relapse. The cost of therapy was significantly lower for patients in the home group ($708 +/- $533 vs $2701 +/- $1717, p < 0.001). These data show that management of hyperemesis in the home is both safe and efficacious. Furthermore, successful therapy can be achieved in the home at a significantly reduced cost.

Sonographic assessment of birth weight among breech presentations.

The objective in this study was to determine whether there was a difference in the accuracy of sonographically determined birth weight estimate in fetuses presenting by the breech as compared to the vertex. Prospectively, 104 consecutive singleton fetuses presented by the breech presentation were identified who also had a sonographic estimate of birth weight within 72 h of delivery. The control group (n = 104) consisted of fetuses presenting by the vertex of women who had the following hospital number and who were of similar demographic characteristics; the birth weight estimate in the control group had to be within 100 g of that of the women with the breech fetus. The estimate of the birth weight was derived for both groups using seven published models. Prediction limits were calculated for an estimated vs. actual birth weight for parturients with breech presentation. Among the study group, the mean standardized absolute error was similar for the seven models (range 120 +/- 104 to 138 +/- 118 g/kg; p = 0.08). For six of the models, the mean standardized absolute error was significantly higher for fetuses in the breech presentation than for fetuses in vertex presentation (range 80 +/- 63 to 112 +/- 95 g/kg; p = 0.02 to < 0.0001). Prediction limit calculations indicate that 99% of the time the actual birth weight was between 1500 and 3999 g if the estimate of birth weight was 2400-2900 g. We conclude that, for fetuses in a breech presentation, the error with most models is significantly higher than for a singleton in the vertex position.

Emergent management of shoulder dystocia.

It is clear that in the vast majority of cases, shoulder dystocia cannot be predicted by the physician. Although macrosomia is strongly associated with shoulder dystocia in retrospective analyses, there are no clinical or sonographic parameters that can reliably and prospectively identify the individual macrosomic fetus. Furthermore, more than 98% of patients with macrosomic fetuses who deliver vaginally do not have shoulder dystocia. Some investigators have advocated the use of cesarean delivery for suspected macrosomic fetuses to avoid potential birth trauma during vaginal delivery; however, this strategy has not been shown to be beneficial in the majority of cases. Boyd and colleagues report that an increase in the cesarean delivery rate for suspected macrosomia from 8% in the 1960s to 21% in 1980 did not improve overall perinatal outcome among macrosomic infants. Since 50% to 90% of cases of shoulder dystocia occur in normally grown fetuses, cesarean delivery for all suspected macrosomic fetuses would not be expected to prevent the vast majority of cases of shoulder dystocia and would expose many mothers to a substantially increased risk for morbidity and mortality. Management of this complex problem requires clinical judgment by the well-trained physician and individualized care for each patient. Because shoulder dystocia remains unpredictable in almost all cases, when it does occur it must be managed expeditiously but carefully with one or more of the maneuvers described. The sequence of manipulations reported herein represents one way of managing shoulder dystocia (Fig. 11). As noted before, however, there are no data to support improved efficacy of one particular sequence over another. The sequence of maneuvers chosen by the clinician should be based on the algorithm with which he or she is most familiar and which has proven successful in their hands. Permanent injury to the fetus fortunately is rare but does occur even in the well-managed case.

Trial of labor after cesarean delivery with a lower-segment, vertical uterine incision: is it safe?

OBJECTIVE: Our purpose was to assess maternal and perinatal outcomes associated with a trial of labor and attempted vaginal birth after prior low-segment vertical cesarean delivery. STUDY DESIGN: During a 10-year period in a single tertiary hospital, all patients with a prior low-segment uterine incision (whether vertical or transverse) were considered candidates for a trial of labor in the absence of other contraindications or patient refusal. Among the 1137 women who underwent low-segment vertical cesarean delivery, 262 were subsequently delivered of 322 live-born infants, and 174 (54%) of them were identified retrospectively as having attempted vaginal birth. The maternal and perinatal outcomes of patients who did or did not undergo a trial of labor were analyzed and compared. RESULTS: No significant differences between the two patient groups were observed regarding demographic characteristics, antepartum complications, gestational age at delivery (mean 37.4 weeks), birth weight, and cord pH at delivery. Vaginal delivery was accomplished successfully in 144 of 174 (83%) patients who underwent a trial of labor. Abdominal delivery was necessary for 17 mothers with labor disorders and 13 with suspected fetal distress. Postpartum hemorrhage occurred more often in the trial of labor group (7/174 [4.0%] vs 2/148 [1.4%], p not significant), but endometritis developed significantly more often in patients with elective repeat cesarean delivery (16.9% vs 6.3%, p = 0.006). Rupture of the low-segment vertical cesarean scar occurred in 2 patients during a trial of labor (1.1%) versus none in the elective repeat cesarean group. Neither mother experienced fetal extrusion or adverse maternal or fetal sequelae. Frequency of serious neonatal complications (8.1% vs 10%) and neonatal mortality (1.7% vs 2.0%) were similar between groups. All neonatal deaths were a result of extreme prematurity or congenital anomalies. CONCLUSIONS: Our experience indicates that a mother with a prior low-segment vertical cesarean delivery can undertake a trial of labor with relative maternal-perinatal safety. The likelihood of successful outcome and the incidence of complications are comparable to those of published experience with a trial of labor after a previous low-segment transverse incision.

Hemorrhage associated with cesarean delivery: when is transfusion needed?

Our objective was to determine the incidence of blood administration after cesarean delivery and whether such transfusions are always beneficial. In this retrospective study 1610 women underwent cesarean delivery during a 2-year period and 127 of these patients had hemorrhage during or after operation. Of these subjects 103 received blood because of intraoperative hemorrhage, a reduction in the hematocrit of more than 10 points, or because the postoperative hematocrit was < 24%. These subjects were compared with the remaining women (n = 24) who met the same criteria for hemorrhage but did not receive transfusion. The maternal age, race, and parity were similar in both groups. The estimated blood loss (873 +/- 484 ml) and the preoperative hematocrit (33.4% +/- 6.4%) in the women who did not receive transfusion were not significantly different from those of patients who received packed red blood cells (854 +/- 576 ml and 30.0% +/- 5.4%, respectively). The postdelivery hematocrit was similar in both groups: 25.9% +/- 4.3% in the nontransfused group and 24.5% +/- 5.6% in the transfused group. Patients in the transfused group received a mean of 3.8 +/- 4.9 units of packed red blood cells, with a range of 1 to 40 units. The mean equilibrated (stable) hematocrit after transfusion was 28.4% +/- 5.4%, which was significantly greater than the mean equilibrated postoperative hematocrit of 22.7% +/- 4.6% in patients who did not receive transfusion (p < 0.0001). Nonetheless, the hospital stay, incidence of postoperative infection, and incidence of wound complications were similar in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

The irritable uterus: a risk factor for preterm birth?

OBJECTIVE: Our aim was to determine the incidence and preterm delivery rate along with the indication for delivery in patients with uterine irritability. STUDY POPULATION: In this retrospective, descriptive study, 17,186 patients with well-defined high-risk factors were compared with 2637 women with uterine irritability. RESULTS: The incidence of preterm labor in patients with uterine irritability was 18.7%, significantly less than in those with other high-risk factors (odds ratio 0.35, 0.31 < odds ratio < 0.38). However, women with uterine irritability who experience preterm labor, compared with other high-risk factors, are much more likely to deliver before 34 weeks' gestation (odds ratio 2.50, 2.07 < odds ratio < 3.03) and more than twice as likely to deliver as a result of advanced preterm labor or membrane rupture (odds ratio 2.20, 1.75 < odds ratio < 2.78). CONCLUSIONS: The incidence of preterm labor in women with uterine irritability is not as frequent as in patients with other high-risk factors. However, preterm labor does occur in patients with uterine irritability at a rate higher than that in the general obstetric population (18.7% vs 11.0%). Because it appears that women with uterine irritability have more resistance to conventional tocolytic therapy, this condition should prompt the physician to use more aggressive perinatal assessment.

Guidelines for management of shoulder dystocia.

Shoulder dystocia is an unpredictable obstetric emergency that occurs in approximately 0.5% of all vaginal deliveries. It appears to result from size discrepancy between the shoulder girdle and the maternal pelvis, abnormal labor mechanics, or both. Many maneuvers have been suggested to free the impacted anterior shoulder, but no specific maneuver or sequence of manipulations has been proved superior. This represents a difficult clinical problem for the obstetrician because it occurs without warning and can result in serious consequences for the infant and increased morbidity in the parturient. This report offers a descriptive review of the various maneuvers that can be used to resolve shoulder dystocia and outlines a suggested sequence that has been successful for these manipulations.

Amniotic fluid interleukin-6 and interleukin-8 levels predict the success of tocolysis in patients with preterm labor.

OBJECTIVE: To determine whether the levels of the cytokines interleukin-6 (IL-6) and IL-8 in amniotic fluid identify patients with preterm labor who are resistant to tocolysis. METHODS: Amniocenteses were performed in 23 women with documented preterm labor at 20-32 weeks' gestational age who were treated subsequently with tocolytics. The concentrations of IL-6 and IL-8 in amniotic fluid were determined by double-antibody radioimmunoassay methods using recombinant human IL standards. RESULTS: Of the 23 patients, five failed to respond to tocolysis (four delivered within 48 hours), and of the remaining 18, all delivered more than 9 days after tocolysis was initiated (mean 31 +/- 10 days; range 9-61). In women who had failed tocolysis, discriminatory concentrations of IL-6 and IL-8 were 20 and 15 ng/mL, respectively. Of the patients who had amniotic fluid concentrations higher than these thresholds, all failed tocolysis (100% positive predictive value) and delivered within 6 days. The patients with levels below these discriminatory concentrations had successful tocolysis, and 17 of 18 delivered more than 2 weeks after treatment (95% negative predictive value). CONCLUSION: The success of tocolysis and thus delivery remote from an episode of preterm labor is associated with discriminatory amniotic fluid IL-6 and IL-8 levels of less than 20 and less than 15 ng/mL, respectively. If the immunologic response that causes the release of IL-6 and IL-8 has not occurred, the likelihood of successful tocolysis is extremely high. However, if both IL-6 and IL-8 are elevated, tocolysis is likely to fail and delivery may occur within 48 hours.

Assessment of fetal well-being using the nonstress test in the home setting.

OBJECTIVE: To determine the feasibility of performing nonstress tests (NSTs) in the home setting instead of the health clinic environment. METHODS: In this prospective study, ten women were tested using a Sonicaid TEAM portable monitor and a Hewlett-Packard device in the health clinic. The women were then instructed on use of the Sonicaid device and were tested once a week in the home as well as in the high-risk clinic. All tests were reviewed independently by two of the authors to assess agreement in interpreting the NST. In the health clinic setting, a nonreactive NST was followed by a nipple stimulation contraction stress test (CST); in the home, a nonreactive NST was followed by maternal voice acoustic stimulation. RESULTS: There was 100% correlation during the concurrent study. Two blinded authors agreed on all tests. During the second phase, eight of the ten subjects had NSTs that were consistently reactive in both the home and office settings. In one woman, a nonreactive NST in the clinic was followed by a negative CST. In the remaining patient, a reactive NST in the health clinic was followed 3 days later by a nonreactive NST in the home, which persisted in the provider's office. CONCLUSION: Nonstress testing in the home appears to be an accurate method of antenatal fetal health assessment that adds convenience and potential cost savings.

Prediction of hemorrhage at cesarean delivery.

OBJECTIVE: To identify and quantitate the risk factors that might be predictive of hemorrhage during abdominal delivery. METHODS: Over a 2-year period, 1610 women underwent cesarean delivery and 127 (7.9%) had hemorrhage, defined as a decrease in hematocrit of 10% or greater, estimated blood loss greater than 1500 mL, or packed red blood cell administration. These women were compared through a case-control study design with the next abdominal birth without hemorrhage that could be matched for age, parity, indication for cesarean delivery, type of anesthesia, type of skin incision, and antepartum hematocrit. RESULTS: Preeclampsia (odds ratio 3.6, 95% confidence interval [CI] 1.8-7.4), disorders of active labor (odds ratio 4.4, 95% CI 1.4-13.7), Native American ethnicity (odds ratio 6.4, 95% CI 1.8-22.4), previous postpartum hemorrhage (odds ratio 8.4, 95% CI 1.9-37.4), and obesity of greater than 250 lb (odds ratio 13.1, 95% CI 1.7-102.7) were all statistically associated with significant bleeding during abdominal delivery. Combinations of two or more of these factors were associated with a markedly increased risk for hemorrhage, with odds ratios of 18.4 or greater. CONCLUSIONS: Patients undergoing cesarean delivery who have factors exposing them to increased risk of hemorrhage can be identified prospectively. These women will benefit greatly from extended preoperative counseling when possible, effective utilization of blood bank technology through type and cross-match requests, and preventive measures during abdominal delivery to minimize blood loss.

Reproductive genetics for couples older than 40 years of age.

The counseling process, which involves genetic screening and prenatal diagnosis, is presented. Also addressed are the recent advances in assisted reproductive technologies, which may prove to be particularly useful for these patients.