Robin B. Kalish

Intraobserver and interobserver reproducibility of fetal biometry

To assess the intra‐ and interobserver reproducibility of ultrasound measurements of fetal biometric parameters.

Birthweight discordance in multiple pregnancy.

This paper reviews several aspects of discordant growth in multiple pregnancies. Discordant growth is not a chance event and therefore several patterns can be discerned. About 75% of twins exhibit < 15% discordance (concordant), 20% are 15-25% (mildly) discordant, and about 5% are more than 25% (severely) discordant. Higher frequencies and increased severity are seen among triplets. Five observations regarding discordance became generally accepted: (a) not all discordant pairs are similar; (b) the larger the discordance level the greater is the risk for an adverse outcome; (c) discordant growth does not necessarily represent growth restriction; (d) a discordance level may have a different clinical implication in different gestational ages; and (e) the smaller fetuses in severely discordant pairs are at disproportionate risk for neonatal mortality. Mild discordance may represent a normal variation between sibs whereas severely discordant pairs often exhibit patterns of growth restriction. Not infrequently, discordance may represent an adaptation to the limited intrauterine space in order to increase gestational age.

First trimester prediction of growth discordance in twin gestations

OBJECTIVE The purpose of this study was to determine whether first trimester ultrasound scanning can identify twin gestations that are at risk for subsequent growth discordance. STUDY DESIGN Ultrasound examinations of dichorionic twin pregnancies between 11 and 14 weeks of gestation were evaluated for growth discordance with crown-rump length. Pregnancies that were complicated by fetal death or anomalies were excluded from the analysis. Birth weight discordance was defined as >or=20% difference in birth weight, relative to the larger twin. Fishers exact, Mann Whitney U, and Spearman rho tests were used for statistical analysis. RESULTS Of 130 twin pregnancies, 16 pregnancies (12.3%) had discordant birth weight. Crown-rump length disparity was correlated positively with birth weight discordance (r=0.31; P<.001). Of pregnancies with a discrepancy of <or=3 days in estimated gestational age, only 9.2% were discordant at birth compared with 45.5% of pregnancies with >3 days discrepancy (P=.004), which resulted in a likelihood ratio of 5.9 for having discordant birth weight. CONCLUSION Twins who are ultimately discordant at birth may exhibit differences in growth as early as 11 to 14 weeks of gestation.

Intrapartum elective cesarean delivery: A previously unrecognized clinical entity

OBJECTIVE: The purpose of the study was to investigate the incidence of intrapartum patient choice cesarean delivery—patients’ requesting cesarean delivery and physicians’ offering it during labor—and factors possibly influencing these requests and offers. METHODS: For a 6-month period from May 1, 2002, to October 31, 2002, obstetricians were asked to complete a questionnaire after all intrapartum cesarean deliveries regarding whether cesarean delivery was offered by the obstetrician or requested by the patient before being medically indicated. Patient medical records and physician demographic information were reviewed. RESULTS: There were 422 cases that met inclusion criteria. Questionnaires were completed in 100% of cases. Cesarean delivery was offered in 13% before a clear medical indication and requested in 8.8%. Older obstetricians, maternal–fetal medicine specialists, and full-time faculty were significantly more likely to offer cesarean delivery (P = .009, P < .001, and P = .015, respectively). Patients who were unmarried or undergoing labor induction were less likely to request cesarean delivery (P = .029 and P = .035, respectively). Maternal age, parity, stage or length of labor, epidural use, gestational age, insurance status, day of week, and time of delivery did not affect whether patients requested or were offered cesarean delivery. CONCLUSION: This study documents a heretofore unrecognized clinical entity: intrapartum elective cesarean delivery. Physician characteristics, as opposed to patient characteristics or intrapartum factors, are a major determinant of whether laboring patients are being offered cesarean delivery. LEVEL OF EVIDENCE: III

First-trimester screening for aneuploidy with fetal nuchal translucency in a United States population

To examine the detection rate of chromosomal abnormalities using a combination of nuchal translucency (NT) and maternal age in a United States population.

Interleukin-1 receptor antagonist gene polymorphism and multifetal pregnancy outcome.

OBJECTIVE The purpose of this study was to determine whether interleukin-1 receptor antagonist and/or interleukin-1beta gene polymorphisms influence multifetal pregnancy outcome. STUDY DESIGN Maternal and neonatal buccal swabs from 51 multifetal gestations were analyzed for interleukin-1 receptor antagonist and interleukin-1beta alleles. Outcome data were obtained subsequently. RESULTS Fetal carriage of interleukin-1 receptor antagonist allele 1 was more than twice as prevalent as the carriage of allele 2. Preterm premature rupture of membranes was observed in 12 of 24 pregnancies (50.0%) in which 2 fetuses tested positive for interleukin-1 receptor antagonist allele 2, as opposed to only 3 of 27 pregnancies (11.1%) in which 1 or neither fetus tested positive for interleukin-1 receptor antagonist allele 2 (P=.005). Similarly, 20 of 26 neonates (76.9%) with documented morbidity tested positive for interleukin-1 receptor antagonist allele 2, as compared with 36 of 78 neonates (46.2%) without morbidity (P=.007). Fetal or maternal interleukin-1beta polymorphisms or maternal interleukin-1 receptor antagonist polymorphisms were unrelated to pregnancy outcome. CONCLUSION Fetal carriage of interleukin-1 receptor antagonist allele 2 was associated with both preterm premature rupture of membranes and neonatal morbidity in women with multifetal pregnancies.

Contemporary practice patterns and beliefs regarding tocolysis among u.s. Maternal-fetal medicine specialists.

OBJECTIVE: To estimate maternal–fetal medicine specialists’ practice patterns and perceived risks and benefits to tocolysis. METHODS: We performed a mail-based survey of all Society for Maternal–Fetal Medicine (SMFM) members in the United States. Subjects were asked whether they would recommend tocolysis and what would be their first-line tocolytic in five scenarios: 1) acute preterm labor; 2) maintenance tocolysis after arrested preterm labor; 3) repeat acute preterm labor; 4) preterm premature rupture of membranes (PROM) without contractions; and 5) preterm PROM with contractions. RESULTS: A total of 827 (46%) SMFM members responded. Ninety-six percent, 56%, 56%, 32%, and 29% would recommend tocolysis for acute preterm labor, repeat acute preterm labor, preterm PROM with contractions, preterm PROM without contractions, and maintenance tocolysis, respectively. The most common first-line tocolytic was magnesium for acute preterm labor (45%) and repeat acute preterm labor (41%); nifedipine was the most common maintenance tocolysis (79%). Eighty percent believed tocolysis was associated with moderate or significant benefit in the setting of acute preterm labor; however, fewer than 50% responded similarly for the other four scenarios. In all five scenarios, more than 50% of respondents indicated there was minimal or no risk associated with tocolysis. Having a nonacademic practice was independently associated with the recommendation for tocolysis. CONCLUSION: Almost all maternal–fetal medicine specialists recommend tocolysis in the setting of acute preterm labor, and many recommend tocolysis for other indications. Magnesium and nifedipine are the most commonly prescribed first-line tocolytics. LEVEL OF EVIDENCE: III

The recommendation for bed rest in the setting of arrested preterm labor and premature rupture of membranes

OBJECTIVE The objective of the study was to estimate practice patterns regarding bed rest in women with preterm premature rupture of membranes (PPROM) and arrested preterm labor. STUDY DESIGN This was a mail-based survey of all Society for Maternal-Fetal Medicine members in the United States asking whether they would recommend bed rest in the setting of arrested preterm labor or PPROM at 26 weeks. Bed rest was defined as no more than 1-2 hours per day out of bed, with permitted activities including bathroom use, bathing, and brief ambulation inside the home/hospital. RESULTS Seventy-one percent and 87% would recommend bed rest for women with cervical dilation and arrested preterm labor and women with PPROM, respectively, even though the majority believed bed rest was associated with minimal or no benefit. Female sex, nonacademic practice, and practice location in the South or West were independently associated with the recommendation for bed rest. CONCLUSION Despite the belief that bed rest is associated with minimal or no benefit, most maternal-fetal medicine specialists recommend bed rest for arrested preterm labor and PPROM. Randomized, prospective trials are needed to evaluate the efficacy of bed rest in these settings.

Patient choice cesarean delivery: ethical issues.

Purpose of review We have recently identified three salient questions within the patient choice cesarean delivery controversy. First, is performing cesarean delivery on maternal request consistent with good professional medial practice? Second, how should physicians respond to or counsel patients who request patient choice cesarean delivery? Third, should patient choice cesarean delivery be routinely offered to all pregnant women? Recent findings In a well informed patient, performing a cesarean delivery on maternal request is medically and ethically acceptable. Physicians, as patient advocates and promoters of overall health and welfare of their patients, however, should, in the absence of an accepted medical indication, recommend against medically unindicated cesarean delivery. While we believe that current evidence supports a physicians decision to accede to an informed patients request for such a delivery, it does not follow that obstetricians should routinely offer elective cesareans to all patients. Summary When a patient makes a request for an elective cesarean delivery, obstetricians, in their capacity as patient advocate, must help guide their patient through the labyrinth of detailed medical information toward a decision that respects both the patients autonomy and the physicians obligation to optimize the health of both the mother and the newborn.

SONOGRAPHIC DETERMINATION OF GESTATIONAL AGE

Appropriate assessment of gestational age is paramount in obstetric care. Making appropriate management decisions requires accurate appraisal of gestational age. Accurate pregnancy dating may assist obstetricians in appropriately counseling women who are at risk of a preterm delivery about likely neonatal outcomes and is also essential in the evaluation of fetal growth and the detection of intrauterine growth restriction. Accurate gestational age is also important in the interpretation of biochemical serum screening test or for counselling patients regarding the option of pregnancy termination. Since clinical data such as the menstrual cycle or uterine size often are not reliable, the most precise parameter for pregnancy dating should be determined by the obstetrician by ultrasound early in the pregnancy. Ultrasound is an accurate and useful modality for the assessment of gestational age in the first and second trimester of pregnancy and, as a routine part of prenatal care, can greatly impact obstetric management and improve antepartum care.