Predictive value of transvaginal cervical length in triplet pregnancies for spontaneous preterm delivery at < or = 32 weeks.

OBJECTIVE: To establish whether cervical length is a predictor of spontaneous preterm delivery at < or = 32 weeks in triplet pregnancies. METHODS: This was a case-control study of all triplet pregnancies followed with more than three sonographic assessments of cervical length at 4-week intervals from 1995 to 2000. Cervical length in women delivered spontaneously at < or = 32 weeks (cases) was compared with that of the remaining women (controls). Statistical analysis included Fisher's exact test, chi2 test, one-way analysis of variance, logistic regression and receiver operating characteristic (ROC) curve to determine optimal cervical length thresholds for spontaneous preterm delivery at < or = 32 weeks. RESULTS: Of the 58 women included in the study, 17 (29%) delivered spontaneously at < or = 32 weeks. The preterm delivery group had similar demographic and obstetric variables, but a higher rate of cerclage placement (65% vs 17%, p < 0.001) than controls. Mean +/- standard deviation cervical length was significantly shorter among cases than controls at 16-20.0 weeks (3.0 +/- 1.2 vs. 3.9 +/- 0.8 cm, p = 0.01), but not at 20.1-24.0 weeks (3.5 +/- 1.1 vs. 3.8 +/- 1.0 cm, p = 0.76). Logistic regression analysis determined that cervical length at 16-20 weeks had an odds ratio of 0.43 (95% CI = 0.23, 0.80) for the prediction of spontaneous preterm delivery at < or = 32 weeks. ROC curve analysis identified a cervical length of < or = 2.6 cm as the optimal threshold for the prediction of spontaneous preterm delivery at < or = 32 weeks (sensitivity 41%, specificity 92%). CONCLUSIONS: In a population of triplet gestations with a 29% rate of preterm delivery, cervical length at 16-20.0 weeks, but not at 20.1-24.0 weeks, was inversely correlated with the probability of preterm delivery at < or = 32 weeks.

Association of sex of the fetus in isolated fetal choroid plexus cysts.

We sought to determine if an association exists between sex of the fetus and the finding of isolated fetal choroid plexus cysts. Of 131 fetuses, 62 were male (47.3%) and 69 were female (52.7%). No statistically significant differences were found in the maternal demographic parameters studied (age, race, gravidity, parity, sonogram timing) or descriptive cyst information obtained (location, number, dimensions, resolution), although bilaterality was more common in male fetuses. The determination that isolated choroid plexus cysts are seen equally frequently in male and female fetuses adds to basic information about such a common sonographic finding.

Characterization and prognostic significance of variable decelerations in the second stage of labor.

The characteristics of variable decelerations (VD) in the second stage of labor and the relationship between the number, frequency, or severity and neonatal outcome have not been studied. We have analyzed the characteristics of VD in the second stage of labor and their prognostic significance in the prediction of Apgar scores. In this descriptive study, fetal heart tracings containing VD from 250 singleton, vaginal deliveries between June 1994 and July 1996 were reviewed blinded to outcome information. Excluded were: (1) deliveries at <36 weeks, (2) uninterpretable tracing, (3) absence of VD in second stage of labor, and (4) absence of exam establishing beginning of second stage of labor. VD characteristics evaluated: shape (U, V, W); anterior and posterior "shoulders"; slow return to baseline (< or = 30-degree curve); cumulative depth of VD per 10 min, second stage oxytocin dose. Outcome information collected: method of delivery, birth weight and Apgar scores. Statistical analysis included regression and analysis of variance (ANOVA). The mean maternal age was 32+/-5 years and gestational age 39+/-1.3 week. In the second stage of labor, the mean oxytocin dose was 3+/-5 mu/min, length of the second stage 65+/-57 min, total number of VD averaged 21+/-17 and uterine contractions 26+/-22 per patient. The percentage of VD <100 bpm was 50+/-27%, VD <70 bpm 13+/-20%, anterior shoulders 76+/-30%, posterior shoulders 75+/-30% and slow return to baseline 12+/-17%. The number of VD significantly increased with the length of the second stage of labor (r=0.85, p <0.001). The total number and percentage of VD <70 bpm were inversely correlated with 5-min Apgar score (p=0.038, 0.015 respectively). The sum of the depth of VD/length of second stage as well as the percentage of VD with anterior and/or posterior shoulders and slow return to baseline were not significantly related to Apgar scores (p=0.08, 0.72, 0.73, 0.99, respectively). Patients with a higher percentage of decelerations with slow return to baseline had a higher rate of operative vaginal deliveries (20 vs. 11 %, p=0.002); but no significant differences in Apgar scores compared with those with spontaneous delivery (p=0.9). Second stage VD <70 bpm were significantly associated with lower 5-min Apgar scores. Although the presence of VD with a slow return to baseline was significantly associated with operative delivery, there was no difference in 5-min Apgar scores.

The effect of propofol on isolated human pregnant uterine muscle.

BACKGROUND: Propofol is an alternative to thiopental as an intravenous induction agent for cesarean section. Because it has relaxant effects on vascular and other smooth muscles, the authors set out to determine whether propofol has any effect on pregnant human uterine smooth muscle in an isolated preparation. METHODS: Myometrial specimens were excised from 10 parturients undergoing elective cesarean section. The muscle strips were suspended in tissue baths and isometric tension was recorded. After establishment of rhythmic contractions in the buffer solution as a control, propofol (0.5 to 10 microg/ml) in fat emulsion was applied cumulatively to the bath. The effect of the fat emulsion at equivalent concentrations was also examined. RESULTS: Propofol concentrations of 2.7 x 10(-6) M (0.5 microg/ml) and 1.1 x 10(-5) M (2 microg/ml) had no significant effect on the active tension developed by muscle contraction. However, propofol at concentration of 5.5 x 10(-5) M (10 microg/ml) reduced the active tension by 45% (P < 0.02) compared with the control value. The fat emulsion had no effects on the active tension. CONCLUSIONS: These results imply that the decline in the active tension of muscle contraction was most likely caused by propofol and not by the fat emulsion. However, the propofol concentrations needed to produce a significant reduction in the uterine muscle tension appear to be much greater than the free propofol concentrations reported by others during cesarean section.

Breath pentane concentrations during labor and the effect of epidural analgesia on the pentane concentration.

Increased lipid peroxidation has been observed in pregnancy and particularly in preeclampsia. Pentane, a by-product of lipid peroxidation, can be measured in exhaled breath, and its measurement is considered a non-invasive method of assessing lipid peroxidation in vivo. We measured pentane levels in the breath of 36 healthy parturient women and examined the effect of epidural analgesia on the pentane level. Single-expiratory breath samples were analyzed by gas chromatography. The breath pentane level was higher during labor (4.88 parts per billion [p.p.b.], 95% confidence interval 3.25-6.51 p.p.b.) than before the induction of labor (3.10 p.p.b., 95% confidence interval 2.01-4.19 p.p.b.). There was a significant decrease in the pentane level after the institution of epidural analgesia (2.27 p.p.b., 95% confidence interval 1.43-3.11 p.p.b.). Our results suggest that labor may be accompanied by an increase in lipid peroxidation, and epidural analgesia reverses this increase.

The effect of glucagon on spontaneous contractility of isolated pregnant uterine muscle.

OBJECTIVE: To determine whether glucagon has relaxant effects on the spontaneous contractions of term pregnant human uterine smooth muscle in an isolated preparation. METHODS: Myometrial specimens were excised from the upper incisional surface of the lower uterine segment in seven women during elective cesarean delivery. The muscle strips were suspended in tissue baths and isometric tension was recorded. After establishing rhythmic spontaneous contractions, glucagon reconstituted with distilled water or the accompanying diluent was added directly to the bath in a cumulative manner. In the second phase of the study, the effect of the diluent (1.6% glycerin with 0.2% phenol) alone on muscle contractility was evaluated. RESULTS: Glucagon had no effect on uterine muscle concentrations when reconstituted with distilled water. However, glucagon reconstituted with the diluent decreased the contractile amplitude by 27 +/- 11% (mean +/- standard deviation, P < .01) and the frequency by 13 +/- 10% (P < .05) at a concentration of 20 micrograms/mL. At a cumulative concentration of 40 micrograms/mL, the reductions in amplitude and frequency were 65 +/- 13% (P < .001) and 18 +/- 14% (P < .01), respectively. The diluent at equivalent concentrations exerted relaxation similar to that produced by glucagon when reconstituted with the diluent. The relaxant effects were not different between the two solutions (P > .2, power 90%, alpha = .05). CONCLUSION: These results suggest that relaxation of contractions was likely caused by the diluent rather than by glucagon. We conclude that glucagon does not have a direct relaxant effect on spontaneous contraction of isolated uterine muscle obtained from term pregnant uteri.

Effect of dantrolene sodium on contractility of isolated human uterine muscle.

The administration of intravenous dantrolene in a parturient susceptible to malignant hyperthermia has been associated with post partum uterine atony. We examined the effect of dantrolene sodium for injection (Dantrium Intravenous) on spontaneous contractility of uterine smooth muscle from women in term pregnancy in an isolated preparation. Dantrolene sodium for injection at 5 microg/ml and 10 microg/ml had no effect on the spontaneous contractility of the uterine muscle preparations. At a cumulative concentration of 20 microg/ml, a mild depression (16 +/- 14%) in the frequency of spontaneous contractions was noted. However, a similar depression in the muscle preparations treated with mannitol suggests that the depression observed with the dantrolene was likely due to the mannitol that was included in the dantrolene formulation rather than to dantrolene sodium itself. We conclude that dantrolene sodium has no effect on the spontaneous contractility of uterine smooth muscle. The depression of uterine muscle activity observed with dantrolene for injection appears attributable to the mannitol.

Renal scans in pregnant transplant patients.

This study demonstrates the normal technetium-99m diethylenetriaminepentaacetic acid ([99mTc]DTPA) renal scan in pregnant patients with transplanted kidneys. Five pregnant renal transplant patients had seven [99mTc]DTPA renal studies to assess allograft perfusion and function. All scans showed the uteroplacental complex. The bladder was always compressed and distorted. The transplanted kidney was frequently rotated to a more vertical position. In all patients allograft flow and function were maintained. There was calyceal retention on all studies and ureteral retention activity in three of five patients. Using the MIRD formalism, the total radiation absorbed dose to the fetus was calculated to be 271 mrad. This radiation exposure is well within NRCP limits for the fetus of radiation workers and an acceptable low risk in the management of these high risk obstetric patients.

Successful outcome of pregnancy in women with hypothyroidism.

Published data on the influence of hypothyroidism on fertility, gestation, and the offspring are controversial. We studied nine hypothyroid women during 11 pregnancies. Mean serum values for thyroxine, triiodothyronine (T3), resin T3 uptake ratio, and thyroid-stimulating hormone were 2.3 microgram/dL, 82 ng/dL, 0.64, and 105 mU/mL, respectively. Four patients had iatrogenic hypothyroidism (three remote thyroidectomy, one remote 131I therapy), two Hashimoto's thyroiditis, and three idiopathic primary hypothyroidism. Seven patients first presented untreated after the 24th week of gestation. Two patients needed cesarean section; seven delivered vaginally. There was one stillborn infant in the only patient with pre-eclampsia. Another infant had Down's syndrome and an ostium primum defect (mother's age, 41 years). The remaining nine infants were normal at birth. All placentas were normal. Follow-up in seven infants up to 2.7 years showed normal thyroid function and somatic development. Infants of hypothyroid mothers may be normal because their hypothalamic-pituitary thyroid axis develops independently from the mother.

The randomized management of term frank breech presentation: a study of 208 cases.

A prospective study of 208 women in labor at term with singleton fetuses in a frank breech presentation was carried out. One hundred fifteen patients were randomized to a vaginal delivery group and 93 to an elective cesarean section group. Of the 93 women scheduled for cesarean section, 88 were delivered according to protocol. Five women progressed rapidly in labor and were delivered vaginally without complications. Of the 115 women scheduled for vaginal delivery, x-ray pelvimetry was obtained on 112. Three women were delivered vaginally without incident before x-ray pelvimetry could be obtained. One of these women was delivered of an infant who died shortly after birth of lethal congenital anomalies. Of the 112 women with x-ray pelvimetry, 52 had one or more inadequate pelvic measurements and were scheduled for indicated cesarean section. Three women, however, were delivered vaginally without incident before operation could be performed. Of the remaining 60 patients in this group, 49 were delivered vaginally without a perinatal death. Eleven women required cesarean section for difficulties during labor. There were no maternal deaths, but 73 (49.3%) of the 148 women who were delivered by cesarean section in this study experienced postpartum morbidity. Only four (6.7%) of the 60 women delivered vaginally had postpartum complications. Based on the data, it seems resonable to allow vaginal delivery in carefully selected cases of term frank breech presentation.

Management of hyperparathyroidism in pregnancy with oral phosphate therapy.

Hyperparathyroidism during pregnancy is associated with greatly increased perinatal morbidity and mortality. Severe neonatal hypocalcemia and tetany is a particularly serious complication. Surgical removal of the abnormal parathyroid glands is currently recommended during pregnancy in view of the severity of the complications in the untreated patients and the favorable results in patients who have had surgery during pregnancy. Two patients are reported in whom surgery during pregnancy could not be performed. They were treated with oral phosphate, which successfully decreased serum calcium; their infants remained normocalcemic throughout the neonatal period. It is suggested that in selected cases medical treatment with oral phosphate can be an effective therapeutic alternative and surgery may be postponed until after delivery.