Effect of labor on infant morbidity and mortality with preterm premature rupture of membranes: United States population-based study.

OBJECTIVE: To evaluate whether labor, in the setting of premature rupture of membranes (PROM), affects infant morbidity and mortality rates. METHODS: We derived data for this population-based cohort study from the United States national linked birth infant death data sets, comprised of singleton live births delivered between 1995 and 1997. We included women (n = 34,594) who had preterm PROM more than 12 hours and delivered between 23 and 32 weeks' gestation. Birth records were used to determine whether delivery occurred with or without labor. Infants with birth weights below the tenth percentile for gestational age were classified as small for gestational age (SGA) on the basis of a nomogram of all singleton births in the United States between 1995 and 1997. Primary outcomes were early neonatal (0-6 days), late neonatal (7-27 days), postneonatal (28-365 days), and infant death (0-365 days). Secondary outcomes included respiratory distress syndrome (RDS), assisted ventilation, and neonatal seizures. Risks of infant mortality and morbidity from labor were examined separately for SGA and non-SGA infants. RESULTS: Overall rates were infant death 11.6%, RDS 15.1%, assisted ventilation 25.9%, and neonatal seizure 0.2%. Labor was associated with higher incidence of early neonatal death in SGA infants (adjusted relative risk [RR] 1.24, 95% confidence interval [CI] 1.11, 1.38) but had no effect on other outcomes. Among non-SGA infants, labor had no effect on infant death but was associated with higher rates of RDS (RR 1.15, 95% CI 1.08, 1.22) and assisted ventilation (RR 1.16, 95% CI 1.08, 1.24). CONCLUSION: Although labor was associated with a slightly higher mortality rate in SGA infants and slightly more respiratory morbidity in non-SGA infants, recommendations regarding clinical treatment should await future clinical trials.

Use of cervical ultrasonography in prediction of spontaneous preterm birth in triplet gestations.

OBJECTIVE: The aim of this study was to assess the role of cervical ultrasonography in the prediction of spontaneous preterm birth in triplet gestations and to compare various ultrasonographic cervical parameters with respect to predictive ability. STUDY DESIGN: This prospective cohort study included 51 triplet gestations longitudinally evaluated between 15 and 28 weeks' gestation on 274 occasions with transvaginal cervical ultrasonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percentage of funneling, and cervical index. RESULTS: Receiver operating characteristic curve analyses showed that cervical lengths of < or =2.5 cm and < or =2.0 cm between 15 and 24 weeks' gestation and between 25 and 28 weeks' gestation, respectively, were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth. A cervical length of < or =2.5 cm between 15 and 20 weeks' gestation had both a specificity and a positive predictive value of 100% for delivery at <28 weeks' gestation, and the sensitivities and negative predictive values ranged from 25% to 50% and from 72% to 91%, respectively, for deliveries at <28, <30, and <32 weeks' gestation. A cervical length of < or =2.5 cm between 21 and 24 weeks' gestation had an 86% sensitivity for prediction of spontaneous delivery at <28 weeks' gestation. A cervical length of < or =2.0 cm between 25 and 28 weeks' gestation had both a sensitivity and a negative predictive value of 100% for delivery at both <28 and <30 weeks' gestation. CONCLUSIONS: In triplet gestations cervical lengths of < or =2.5 cm between 15 and 24 weeks' gestation and < or =2.0 cm between 25 and 28 weeks' gestation were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth.

Hepatic hemangioendothelioma: prenatal sonographic findings and evolution of the lesion.

We describe a case of hepatic hemangioendothelioma that was first suspected based on prenatal sonographic findings at 19 weeks' menstrual age. At 16 weeks, the patient presented with a markedly elevated maternal serum alpha-fetoprotein level. Serial sonographic examinations revealed that the fetus had cardiomegaly, hepatomegaly with a hepatic mass and dilated intrahepatic vessels, a single umbilical artery, and a placental chorioangioma. Arteriovenous shunting within the hepatic mass was seen using color Doppler and pulsed Doppler sonography. An enlarged artery arising from the abdominal aorta supplying the mass was demonstrated. Postnatal physical examination and radiologic studies supported the diagnosis of hepatic hemangioendothelioma. The evolution in the sonographic appearance of this hepatic lesion in utero over a 17-week period is described.

Foot length in fetuses with abnormal growth.

Sonographic fetal foot length is highly predictive of gestational age. In order to assess the reliability of this parameter in predicting gestational age in cases of abnormal fetal growth, we examined fetal foot length in small- and large-for-gestational-age fetuses. A nomogram of foot length versus gestational age between 15 and 37 weeks was constructed using cross-sectional data obtained from 5372 singleton fetuses. Fetal foot lengths for small-for-gestational-age fetuses (estimated fetal weight below the 10th percentile) and large-for-gestational-age fetuses (above the >90th percentile) fetuses were plotted against the foot length nomogram in order to determine the number of small-for-gestational-age fetuses and large-for-gestational-age fetuses with foot lengths below the 10th and above the 90th percentiles, respectively. Of the 586 small-for-gestational-age fetuses, 355 (60.6%) had foot lengths below the 10th percentile on the nomogram. When foot lengths from large-for-gestational-age fetuses were plotted on the foot length nomogram, 29.4% (219 of 744) had measurements above the 90th percentile. Fetal foot length can be influenced by growth restriction as well as states of accelerated fetal growth. Our findings imply that there are limitations to the use of fetal foot length for gestational age assessment, particularly in fetuses with growth abnormalities.

Value of maintenance therapy with oral tocolytics: a systematic review.

OBJECTIVE: The objective was to perform a systematic review of prospective randomized trials evaluating the efficacy of oral tocolytics in the prevention of recurrent preterm labor and its associated complications. METHODS: A MEDLINE search of English language articles published since 1966 was performed to identify studies of maintenance oral tocolytic therapy. Studies were included in the review which: 1) randomized patients to an oral tocolytic after stabilization with parenteral therapy; 2) reported results for either a placebo or a control group; and 3) included patients with intact membranes only. These studies were analyzed for nine outcomes, including incidence of preterm delivery, incidence of recurrent preterm labor, latency from treatment to delivery, gestational age, birthweight, admission to an intensive care nursery (ICN), incidence of respiratory distress syndrome (RDS), incidence of intraventricular hemorrhage (IVH), and perinatal mortality. RESULTS: Seven studies met the inclusion criteria, four of which used oral terbutaline for the treatment arm (two had a control group, and two had a placebo group), and one used oral ritodrine (with a placebo group). Of the remaining two, one used oral ritodrine and oral magnesium chloride (with a control group), and the other used oral terbutaline and oral magnesium chloride (with a placebo group). The results of the individual studies suggest that there was no beneficial effect of oral tocolytic therapy on the incidence of preterm delivery (odds ratio (OR) range: 0.7-2.0), incidence of preterm labor recurrence (OR range: 0.6-3.2), ICN admission (OR range: 1.3-2.0), incidence of RDS (OR range 0.1-4.3), incidence of IVH (OR range 0.3-2.0), perinatal mortality (OR range: 1.6-4.3), or gestational age at delivery. CONCLUSIONS: We concluded that a meta-analysis based on the available studies is not possible due to the fact that there is little that these seven studies have in common with respect to treatment comparisons. In addition, inconsistent definitions of outcome variables makes pooling this data inappropriate and invalid. Therefore, well-designed, large, randomized trials are needed to evaluate the efficacy of oral tocolytics in improving perinatal outcome.