Rescue corticosteroids in twin pregnancies and short-term neonatal outcomes.

OBJECTIVE: To estimate the efficacy of a rescue course of antenatal corticosteroids in twin pregnancies. DESIGN: Retrospective cohort study. SETTING: Tertiary-care centre. POPULATION: Twins born from 24 to <34 weeks of gestation in a single maternal and fetal medicine practice from 2006 to 2011. METHODS: We compared neonatal outcomes in 88 twins exposed to a single course of corticosteroids with outcomes in 42 twins exposed to two courses of corticosteroids: the initial course and a single rescue course. Analyses were adjusted to control for correlation between twins born to the same mother. MAIN OUTCOME MEASURE: Short-term neonatal respiratory morbidity. RESULTS: Rescue corticosteroids were associated with fewer days of mechanical ventilation (7.3 ± 3.3 versus 33.9 ± 25.3 days, P = 0.003), fewer days with a fraction of inspired oxygen of >21% (6.3 ± 4.3 versus 33.3 ± 25.8 days, P = 0.003), a lower incidence of mechanical ventilation >14 days or death while on mechanical ventilation (0 versus 12.5%, P = 0.016), and a lower incidence of retinopathy of prematurity (0 versus 12.5%, P = 0.016). The proportion of neonates with respiratory distress syndrome did not differ between the groups (adjusted odds ratio 1.28, 95% confidence interval 0.50-3.26). There were no differences found for birthweight, head circumference and length. CONCLUSIONS: In twins born before 34 weeks of gestation, exposure to rescue corticosteroids may be associated with improved neonatal outcomes. Further studies are warranted to assess the effect of rescue corticosteroids in twin pregnancies.

Cervical length at 30-32 weeks and the risk of Cesarean delivery in twin pregnancies.

OBJECTIVES: To estimate the association between the cervical length (CL) measurement at 30-32 weeks and the mode of delivery in twin pregnancies. METHODS: This was a retrospective study of a cohort, from 2005-2010, of 265 twin pregnancies with a CL measurement at 30-32 weeks. We compared the CL measurement at 30-32 weeks based on mode of delivery. We then analyzed our data across four subgroups, based on the CL measurement quartiles at 30-32 weeks. We performed this analysis in all patients, and also performed a planned subgroup analysis of 130 patients who attempted a vaginal delivery. RESULTS: In all patients, including those who attempted a vaginal delivery, the mean CL at 30-32 weeks was significantly shorter in women who delivered vaginally compared with women who had a Cesarean section. The likelihood of Cesarean delivery increased significantly with increasing CL measurement across the groups defined by measurement quartiles. On adjusted analysis controlling for maternal age, race, in-vitro fertilization, chorionicity, induction of labor and prior vaginal delivery, the CL measurement at 30-32 weeks was independently associated with mode of delivery. CONCLUSIONS: In twin pregnancies, the CL at 30-32 weeks is significantly associated with the likelihood of Cesarean delivery. A longer CL may represent underdevelopment of the uterus, leading to a higher risk of Cesarean delivery in labor at term.

Intravaginal misoprostol versus Foley catheter for labour induction: a meta-analysis.

BACKGROUND: There are a number of agents used for cervical ripening prior to the induction of labour. Two commonly used agents are intravaginal misoprostol and a transcervical Foley catheter. OBJECTIVE: To review the evidence comparing misoprostol and transcervical Foley catheter placement for induction of labour, and perform a meta-analysis comparing these two induction agents. SEARCH STRATEGY: We conducted database searches of PubMed, Embase, the Cochrane Library Database, and the ClinicalTrials.gov website. Bibliographies of all relevant articles were reviewed. SELECTION CRITERIA: Prospective, randomised trials comparing the use of intravaginal misoprostol and transcervical Foley catheter for the purpose of cervical ripening and induction of labour were included. We excluded studies in which the patients in these two intervention groups also received other induction agents concurrently, such as oral misoprostol, oxytocin, or other prostaglandins. DATA COLLECTION AND ANALYSIS: The primary outcomes selected were time to delivery, and the rates of caesarean section, uterine tachysystole, and chorioamnionitis. Random-effects generalised linear models with a poisson distribution and log link function were used to compare the two induction agents across the studies. MAIN RESULTS: Nine studies (1603 patients) were identified as eligible to be included in this meta-analysis. There were no significant differences in the mean time to delivery (mean difference 1.08 ± 2.19 hours shorter for misoprostol, P = 0.2348), the rate of caesarean delivery (RR 0.991; 95% CI 0.768, 1.278), or in the rate of chorioamnionitis (RR 1.130; 95% CI 0.611, 2.089) between women who received misoprostol compared with transcervical Foley catheter. Patients who received misoprostol had significantly higher rates of tachysystole compared with women who received a transcervical Foley catheter (RR 2.844; 95% CI 1.392, 5.812). CONCLUSIONS: Intravaginal misoprostol and transcervical Foley catheter have similar effectiveness as induction agents. Transcervical Foley catheter is associated with a lower incidence of tachysystole.

Amniotic fluid index as a predictor of latency after preterm premature rupture of the membranes.

To determine if latency following preterm premature rupture of membranes can be predicted using the amniotic fluid index, a retrospective observational study was performed using patient records to identify those admitted with a diagnosis of preterm premature rupture of membranes. Fifty-one patients with initial evaluation within 48 hours of rupture and gestational age 26 to 34 weeks were identified. Amniotic fluid index was evaluated along with a biophysical profile; these were followed serially until delivery. Delivery was accomplished because of spontaneous labor or chorioamnionitis. Amniotic fluid index at initial evaluation was stratified into three groups: Low (less than 5.0), reduced (4.0 to 7.9), and normal (8.0 or higher). Latency in days from preterm premature rupture of membranes to delivery was evaluated for these groups. A difference was noted in that latency was significantly longer in the group with normal versus low or reduced amniotic fluid index groups. The amount of residual amniotic fluid, as measured by the amniotic fluid index, following preterm premature rupture of membranes, is predictive of latency.

Emergency peripartum hysterectomy.

OBJECTIVES: By means of hospital-based data over 9 years we sought to evaluate the clinical indications and incidence of emergency peripartum hysterectomy by demographic characteristics and reproductive history. STUDY DESIGN: From the obstetric records of all deliveries at Brigham and Women's Hospital between Oct. 1, 1983, and July 31, 1991, we identified all women undergoing emergency peripartum hysterectomy, calculated crude and adjusted incidence rates, conducted statistical tests of linear trends and heterogeneity, and observed the clinical indications preceding the onset of this procedure. RESULTS: There were 117 cases of peripartum gravid hysterectomy identified during this period, for an overall annual incidence of 1.55 per 1000 deliveries. The rate increased with increasing parity and was significantly influenced by placenta previa and a history of cesarean section. The incidence by parity increased from one in 143 deliveries in nulliparous women with placenta previa to one in four deliveries in multiparous women with four or more deliveries with placenta previa. Likewise, the incidence increased from one in 143 deliveries in women with one prior live birth and a prior cesarean section to one in 14 deliveries in multiparous women with four or more deliveries with a history of a prior cesarean section. Both these trends were highly significant (p < 0.001). Abnormal adherent placentation was the most common cause preceding gravid hysterectomy (64%, p < 0.001), with uterine atony accounting for 21%. Although no maternal deaths occurred, maternal morbidity remained high, including postoperative infection in 58 (50%), intraoperative urologic injury in 10 patients (9%), and need for transfusion in 102 patients (87%). CONCLUSIONS: The data identify abnormal adherent placentation as the primary cause for gravid hysterectomy. The data also illustrate how the incidence of emergency peripartum hysterectomy increases significantly with increasing parity, especially when influenced by a current placenta previa or a prior cesarean section. Maternal morbidity remained high although no maternal deaths occurred.

Assessment of right and left ventricular function in terms of force development with gestational age in the normal human fetus.

OBJECTIVE: To assess right and left ventricular systolic function in normal human fetuses by cross sectional Doppler echocardiography to calculate the force developed by myocardial shortening. DESIGN: Cross sectional echocardiographic images of the aorta and pulmonary arteries were obtained prospectively in order to measure great vessel diameters and calculate their cross sectional areas. Doppler velocity signals were recorded from the proximal aorta and the proximal pulmonary artery and digitised to obtain peak velocity, acceleration time, flow velocity time integral during acceleration, and the flow velocity time integral for the whole of ejection. Right and left ventricular force development was estimated by Newton's equation in which force is defined as the product of mass and acceleration. PATIENTS: 58 normal human fetuses at a gestational age of from 20 to 42 weeks. RESULTS: The cross sectional area of the pulmonary artery was 20% greater than that of the aorta. Aortic acceleration time was longer than that in the pulmonary artery, and peak blood flow velocity in the aorta was consistently greater than that in the pulmonary artery. Right ventricular stroke volume was significantly greater than left ventricular stroke volume. The force developed by the right and left ventricles was, however, similar throughout the gestational period studied, increasing tenfold from 20 weeks' gestation to term (r = 0.74, p less than 0.0001; r = 0.75, p less than 0.0001) respectively. CONCLUSION: The development of right and left ventricular force in the human fetus is similar in spite of the greater volume handled by the right ventricle. This index of ventricular performance does not require calculation of ventricular volume and because it varies independently of ventricular geometry and heart rate it should prove useful in assessing cardiac function in the normal human fetus and in fetuses with ventricular dysfunction.

Prenatal diagnosis of lissencephaly.

We report two cases of prenatal detection of lissencephaly by high-resolution ultrasound. The first case studied was referred for high-risk obstetrical management and serial antenatal ultrasounds because of a family history of lissencephaly in an unresolved chromosomal abnormality. Diagnosis of a smooth gyral pattern consistent with lissencephaly was made at 32 weeks' gestation. The second case was referred for prenatal ultrasound because of a size versus dates discrepancy. The ultrasound examination showed a smooth gyral pattern at 31.5 weeks. In light of this ultrasound finding, a fetal blood sample was obtained and a chromosomal abnormality reported, confirming the diagnosis. To our knowledge, these cases represent the first report of the sonographic prenatal diagnosis of cerebral agyria or lissencephaly.

Intrauterine growth retardation: diagnosis based on multiple parameters--a prospective study.

A scoring system has previously been developed to diagnose intrauterine growth retardation (IUGR) based on three parameters: estimated fetal weight, amniotic fluid volume, and maternal blood pressure status. To test the IUGR score prospectively, the authors computed the score in 356 third-trimester fetuses, 39 growth retarded and 317 normal, scanned within 2 weeks prior to delivery. The IUGR score identified three groups, each with a distinct probability of IUGR: A score below 50 virtually excludes IUGR (3% probability), a score above 60 allows confident diagnosis (74% probability), and score of 50-60 is indeterminate (13% probability). The IUGR score performed best in patients with accurate dating by early ultrasound (US), but even among patients lacking accurate dating, the performance of the IUGR score was superior to that previously reported for any single sonographic parameter. The IUGR score can be used in any US facility to diagnose or exclude third-trimester IUGR.

Changes in placental blood flow in the normal human fetus with gestational age.

We assessed fetoplacental blood volume flow and placental resistance prospectively with Doppler sonography in 74 normal human fetuses of 19 to 42 wk gestation to determine the changes in placental perfusion with gestational age. Placental blood volume flow was assessed from the umbilical vein as the product of the mean flow velocity integral and the cross-sectional area of the umbilical vein. Placental resistance was assessed as the ratio of maximum systolic and minimum diastolic blood flow velocities from an umbilical artery. Umbilical vein blood volume flow increased exponentially (r = 0.86) with gestational age from 19 wk to term, and did not decrease in postdate fetuses. Umbilical vein blood volume flow increased linearly with fetal weight (r = 0.77), although volume flow per unit body weight changed little with gestational age. Umbilical artery velocity ratio decreased progressively, indicating diminishing placental resistance with gestational age, but did not correlate closely with umbilical vein blood volume flow. We submit that fetoplacental blood volume flow can be readily calculated directly from the umbilical vein with Doppler ultrasound and may provide a better index of placental perfusion than the umbilical artery velocity ratio.

The cardiac, obstetric, and anesthetic management of pregnancy complicated by acute myocardial infarction.

Myocardial infarction (MI) occurring during pregnancy is a rare but potentially lethal event for both mother and fetus, particularly when it occurs in the third trimester or peripartum period. The authors report two cases of MI occurring in the third trimester of pregnancy and review the literature. Management of the acute infarct and the medical, obstetric, and anesthetic considerations in such patients during labor and delivery are discussed. Successful use of percutaneous transluminal coronary angioplasty is described in a patient with evolving MI and ongoing pain. The preferred method of delivery in the pregnant MI patient is addressed, with emphasis on the need for individualization of care and coordination between the cardiac, obstetric, and anesthetic teams. Finally, the authors review the risks of subsequent pregnancy in this patient population.

Abnormal karyotype of fetuses with omphalocele: prediction based on omphalocele contents.

The majority of fetuses with omphalocele have other congenital abnormalities and, in many cases, an abnormal karyotype. We retrospectively studied 22 consecutive fetuses with sonographically diagnosed omphalocele and available karyotype to determine whether the contents of the omphalocele could predict the karyotype. Of these 22 fetuses, 18 had normal and four had abnormal karyotypes. Sixteen of the karyotypically normal fetuses had liver herniated into the omphalocele and two had only bowel present in the defect. All four of the fetuses with abnormal chromosomes had only bowel in the defect.

Sonographic diagnosis of abnormal fetal genitalia.

Sonographic fetal gender determination is undertaken as part of many prenatal ultrasound examinations. We describe three abnormalities of the fetal phallus, two that were related to family history and one that was associated with other genitourinary tract abnormalities of the fetus. Examination of the fetal genitalia is an important part of the sonographic examination, particularly when there is a genitourinary fetal anomaly or a family history of abnormal genitalia, because the external genitals are a part of the genitourinary tract that can occasionally be malformed. Caution is advisable in the sonographic gender determination in these cases.

Prematurity among insulin-requiring diabetic gravid women.

From Jan. 1, 1983, through Dec. 31, 1987, 420 gravidas with insulin-requiring diabetes antedating pregnancy delivered on the Joslin Clinic service. Among them, 110 pregnancies (26.2% of the total) delivered before 37 completed weeks of gestation compared with a 9.7% incidence (906/9368) for the general population at the Brigham and Women's Hospital during calendar year 1985. Thirty-three percent of all premature deliveries were the result of the development of preeclampsia. The relative risk of prematurity for diabetic patients with any hypertensive complication was 2.0 (95% confidence interval, 1.40 to 2.87) compared with normotensive diabetic subjects. Compared with the general population, most of the excess risk of prematurity was confined to hypertensive diabetics and normotensive patients of more advanced White class. A history of having had a previous premature delivery, increasing duration of diabetes antedating pregnancy, and carrying a male fetus in the index pregnancy were significantly associated with premature delivery. Future efforts to reduce the incidence of prematurity among diabetic gravidas should be directed toward reducing the incidence of preeclampsia.

Sonographic evaluation of hydrops fetalis.

Sonographic criteria were developed to aid in determining the cause of hydrops fetalis in 26 consecutive cases diagnosed antenatally. This enabled us to predict whether the hydrops was due to anemia-related causes (isoimmunization, fetomaternal hemorrhage, alpha-thalassemia) or non-anemia-related causes. Fetuses without anemia as the cause of hydrops most often exhibited pleural effusions (87%) or marked edema (62.5%). A combination of pleural effusions and marked edema was evident in fetuses without anemia 56.3% of the time. Those with anemia as the cause of hydrops were significantly less likely to exhibit pleural effusions (20%), marked edema (10%), or pleural effusions and marked edema (10%). A thickened placenta occurred significantly more frequently (80 versus 37%) in anemia-associated hydrops. With the use of cordocentesis and intravascular in utero transfusion, the early recognition and treatment of hydrops fetalis due to anemia should lead to improved outcome in fetuses so affected.

Sonographic sign suggesting the prenatal diagnosis of coarctation of the aorta.

Coarctation of the aorta is a serious heart defect that can be successfully treated if identified early. Actual narrowing of the aortic isthmus is very difficult if not impossible to demonstrate on prenatal sonography; however, the indirect sign of discrepant ventricular sizes (right ventricle [RV] greater than left ventricle [LV]) is potentially useful to identify fetuses at risk for having coarctation of the aorta. We report on nine fetuses, 18 to 38 weeks gestation, in which the left ventricle was smaller than the right ventricle. After birth, four of the nine had coarctation of the aorta. One infant with Down's syndrome had a patent ductus arteriosus as well as foramen ovale. Another infant had a small left ventricle and parachute mitral valve but no coarctation. The last three infants had a normal cardiac workup at birth. We conclude that a small left ventricle compared to the right ventricle on prenatal sonography can be a sign of congenital heart disease and that one of the defects that can give this appearance is aortic coarctation. Careful neonatal follow-up is warranted.

Early amniocentesis for prenatal cytogenetic evaluation.

Early amniocentesis at 11-14 weeks gestation was evaluated in 100 consecutive patients to see how this technique compares with later amniocentesis. There were no complications as a consequence of the procedure or related pregnancy losses of chromosomally normal fetuses. Samples obtained from three (3%) patients showed insufficient cell growth; two of these patients elected a repeat procedure, which yielded a normal karyotype in each case. There were five abnormal karyotypes, one of which was a culture artifact; in the latter case, repeat amniocentesis at 15 weeks yielded a normal result. Of the 95 pregnancies with normal karyotypes, 94 were progressing normally at follow-up, and one patient elected pregnancy termination because of maternal indications. It appears that early amniocentesis may be an attractive alternative to traditional amniocentesis, in that it provides results at an earlier gestational age and may avoid certain disadvantages of chorionic villus sampling.

Management of isoimmunized pregnancy by use of intravascular techniques.

Twenty-two patients who had 23 pregnancies complicated by isoimmunization were managed by the use of intravascular methods on an outpatient basis. Nine patients underwent 30 percutaneous fetal blood sampling procedures to determine fetal blood type or hematocrit, without complication. Thirteen patients underwent 45 intrauterine fetal transfusions via the umbilical vessels and 16 intraperitoneal fetal transfusions. The overall survival rate in this series was 85.7%. Survival among fetuses that were hydropic at initial evaluation was 83.3%. The procedure-related perinatal mortality rate for intravascular intrauterine transfusions was 2.2%. Knowledge of fetal blood type and hematocrit allowed treatment individualized to the specific needs of each patient. In particular, the ability to transfuse blood directly into the vascular system of the hydropic fetus proved to be lifesaving in those patients.

Improved prediction of intrauterine growth retardation with use of multiple parameters.

Several sonographic parameters have been proposed for predicting intrauterine growth retardation (IUGR), but each has been shown to have a low positive predictive value. To predict IUGR more reliably, the authors developed a multiparameter approach based on sonographic and clinical data from 62 fetuses with IUGR and 91 normal fetuses. Logistic regression analysis revealed that the combination of sonographically estimated fetal weight, amniotic fluid volume, and maternal blood pressure status best correlates with the presence or absence of IUGR and produced an IUGR scoring system based on these three parameters. The scoring system, which has a range of 0-100, was tested on a second set of fetuses (47 with IUGR, 81 normal) to determine its performance characteristics. An IUGR score below 50 virtually excludes the diagnosis of IUGR (0.9% likelihood of IUGR, or negative predictive value of 99.1%). A score above 75 allows confident diagnosis of IUGR (positive predictive value, 82%). A score of 50-75 is equivocal, in that it is associated with an intermediate (24%) likelihood of IUGR. The IUGR score is a practical tool that can be easily used in any ultrasound facility.

Fetal cystic adenomatoid malformation of the lung: apparent improvement in utero.

Fetal cystic adenomatoid malformation is a rare pulmonary abnormality, usually involving only a part of the lung, that is characterized by excessive growth of the terminal respiratory elements. The natural history of this lesion and hence the prognosis after antenatal detection is still unclear. We report two cases of large cystic adenomatoid malformation, diagnosed prenatally, in which the size of the mass diminished visibly during the third trimester. Both fetuses had excellent outcomes after surgery. These findings suggest that when a cystic adenomatoid malformation is diagnosed antenatally, the initial impression concerning the size of the mass and final prognosis may not necessarily predict outcome, because there may be improvement during fetal life.

Fetal abnormalities: diagnosis or treatment with percutaneous umbilical blood sampling under continuous US guidance.

Percutaneous umbilical blood sampling has become an important tool in maternal-fetal medicine and allows direct access to fetal blood. In 52 patients, 100 successful consecutive blood sampling procedures were done for a variety of indications, including 20 intravascular intrauterine fetal transfusions for isoimmune disease. Indications, technique, and complications in this series of percutaneous umbilical blood sampling procedures are described.