Jeffrey L. Ecker

Birth weight as a predictor of brachial plexus injury

Objective To examine the relationship between birth weight and brachial plexus injury and estimate the number of cesareans needed to reduce such injuries. Methods All 80 neonatal records coded for brachial plexus injury from October 1985 to September 1993 at the Brigham and Womens Hospital in Boston, Massachusetts, were studied along with linked maternal files. Birth weight, method of delivery, presence or absence of shoulder dystocia, and any diagnosis of maternal gestational or nongestational diabetes were abstracted. Data for the group with brachial plexus injury were compared with data for live-born infants without this injury during the same period. The sensitivity and specificity of birth weight as a predictor of brachial plexus injury were calculated. Further, the number of cesarean deliveries necessary to prevent a single brachial plexus injury was estimated using various weight cutoffs (4000, 4500, and 5000 g) for elective cesarean delivery. Results Among 77,616 consecutive deliveries, there were 80 brachial plexus injuries identified, for an incidence of 1.03 per 1000 live births. The incidence of brachial plexus injury increased with increasing birth weight, operative vaginal delivery, and the presence of glucose intolerance. In the group of women without diabetes, between 19 and 162 cesarean deliveries would have been necessary to prevent a single immediate brachial plexus injury. Among women with diabetes, between five and 48 additional cesareans would have been required. Conclusion Although birth weight is a predictor of brachial plexus injury, the number of cesarean deliveries necessary to prevent a single injury is high at most birth weights. Because of the large number of cesarean deliveries needed to prevent a single brachial plexus injury in infants born to women without diabetes, it is difficult to recommend routine cesarean delivery for suspected macrosomia in these women.

Postpartum diabetes screening in women with a history of gestational diabetes.

OBJECTIVE: Women with a history of gestational diabetes mellitus (GDM) are at high risk for developing type 2 diabetes (diabetes mellitus, DM). The American Diabetes Association recommends regular postpartum diabetes screening for women with a history of GDM, but the American College of Obstetricians and Gynecologists (ACOG) is not as directive. We sought to examine postpartum glycemic testing in women diagnosed with GDM. METHODS: We conducted an observational cohort study of women diagnosed with GDM at one of two large academic medical centers between 2000 and 2001. Kaplan-Meier estimates of the time from delivery to the first postpartum DM screening tests were determined, and predictors of postpartum DM screening were examined using Cox proportional hazards testing. RESULTS: Only 37% of eligible women underwent the postpartum diabetes screening tests recommended by the American Diabetes Association (fasting glucose or oral glucose tolerance test [OGTT]), with a median time from delivery to the first such testing of 428 days. By comparison, 94% of women underwent postpartum cervical cancer screening using a Papanicolaou (Pap) test, with a median time from delivery to Pap testing of 49 days. Even when random glucose testing was included in a broad definition of postpartum DM screening (random or fasting glucose, glycosylated hemoglobin, or OGTT), only two thirds of women (67%) received a postpartum glycemic assessment. CONCLUSION: In the population studied, only 37% of women with a history of GDM were screened for postpartum DM according to guidelines published by the American Diabetes Association. Efforts to improve postpartum DM screening in this high-risk group are warranted. LEVEL OF EVIDENCE: II-2

The sonographic diagnosis of Dandy-Walker and Dandy-Walker variant: associated findings and outcomes.

Outcomes of pregnancies with sonographically diagnosed Dandy–Walker (DW) or Dandy–Walker variant (DWV) syndromes vary widely. We examined our own experience with these diagnoses in an effort to identify those sonographic features that best predicted neonatal outcome. We identified 50 fetuses with DW and 49 with DWV diagnosed sonographically. Eighty‐six per cent of fetuses with DW and 85% of fetuses with DWV had other sonographically identifiable anomalies, the most common being ventriculomegaly (DW: 32%; DWV: 27%) and cardiac defects (DW:38%; DWV: 41%). Forty‐six per cent and 36% of available karyotypes in cases of DW and DWV, respectively, were abnormal. 50 out of 99 women in our series elected pregnancy termination. Only three pregnancies with DW resulted in a living infant, and only one of these had a normal paediatric examination at six‐week follow‐up. Thirteen out of 49 infants with DWV survived the neonatal period and 7 of 13 were reported initially as normal infants, including six with an isolated finding of DWV. We conclude that overall, the prognosis for these posterior fossa defects is grim but not uniformly fatal. The presence of other anomalies is associated with the worst prognosis. Isolated Dandy–Walker variant has the highest chance of leading to a normal neonate. Copyright

Is a Rising Cesarean Delivery Rate Inevitable? Trends in Industrialized Countries, 1987 to 2007

BACKGROUND  Cesarean delivery rates have been rising rapidly in many countries in the last decade. The objective of this research is to examine cesarean rates in industrialized countries and assess patterns in the trends toward increasing rates. METHODS We examined cesarean delivery rates per 1,000 live births from 1987 to 2007 in 22 industrialized countries. To enhance comparability, the inclusion criteria were at least 50,000 births annually and a per capita gross domestic product of at least U.S.

First Trimester Vitamin D, Vitamin D Binding Protein, and Subsequent Preeclampsia

10,000 in 2007. Poisson regression was selected to model the cesarean delivery rates of countries across time. RESULTS  We examined overall cesarean delivery rates, absolute changes in these rates, and changes in trend lines for cesarean rates for the period from 1987 to 2007. In 2007, 11 of the 21 countries reported overall cesarean rates of more than 25 percent, led by Italy (39%), Portugal (35%), the United States (32%), and Switzerland (32%). Five countries, the Slovak Republic, Czech Republic, Ireland, Austria, and Hungary more than doubled their cesarean delivery rate between 1992 and 2007. Comparing changes in rates across time periods, 14 countries experienced a greater increase in rates in the period between 1998 and 2002 compared with the period between 1993 and 1997. Comparing trends from 2003-2007 to 1998-2002, eighteen countries experienced a slowing down of rate increases across these two periods. CONCLUSION  Although cesarean delivery rates continue to rise, the rate of increase appears to be slowing down in most industrialized countries.

Outcomes, Safety, and Resource Utilization in a Collaborative Care Birth Center Program Compared With Traditional Physician-Based Perinatal Care

Previous studies report an association between vitamin D deficiency and hypertension, including the pregnancy-specific disorder preeclampsia. Circulating vitamin D is almost entirely bound to vitamin D binding protein, which increases 2-fold during pregnancy and previous studies have not examined vitamin D binding protein or free vitamin D levels. We performed a nested case-control study within the Massachusetts General Hospital Obstetric Maternal Study, measuring first trimester total 25-hydroxyvitamin D (25[OH]D) and vitamin D binding protein and calculating free 25(OH)D levels. We compared these levels from pregnancies complicated by subsequent preeclampsia (cases, n=39) with those from normotensive pregnancies (controls, n=131). First trimester total 25(OH)D levels were similar in cases and controls (27.4±1.9 versus 28.8±0.80 ng/mL; P=0.435). Despite an association between higher first trimester blood pressures and subsequent preeclampsia, first trimester total 25(OH)D was not associated with first trimester systolic (r=0.11; P=0.16) or diastolic blood pressures (r=0.03; P=0.72). Although there was a trend toward increased risk of preeclampsia with 25(OH)D levels <15 ng/mL (odds ratio: 2.5 [95% CI: 0.89 to 6.90]), this was attenuated after adjustment for body mass index and other covariates (odds ratio: 1.35 [95% CI: 0.40 to 4.50]). First trimester vitamin D binding protein and free 25(OH)D levels were similar in cases and controls and were not associated with first trimester blood pressures. These data suggest that first trimester total and free 25(OH)D levels are not independently associated with first trimester blood pressure or subsequent preeclampsia.

Insulin Resistance and Alterations in Angiogenesis. Additive Insults That May Lead to Preeclampsia

OBJECTIVE We compared outcomes, safety, and resource utilization in a collaborative management birth center model of perinatal care versus traditional physician-based care. METHODS We studied 2957 low-risk, low-income women: 1808 receiving collaborative care and 1149 receiving traditional care. RESULTS Major antepartum (adjusted risk difference [RD] = -0.5%; 95% confidence interval [CI] = -2.5, 1.5), intrapartum (adjusted RD = 0.8%; 95% CI = -2.4, 4.0), and neonatal (adjusted RD = -1.8%; 95% CI = -3.8, 0.1) complications were similar, as were neonatal intensive care unit admissions (adjusted RD = -1.3%; 95% CI = -3.8, 1.1). Collaborative care had a greater number of normal spontaneous vaginal deliveries (adjusted RD = 14.9%; 95% CI = 11.5, 18.3) and less use of epidural anesthesia (adjusted RD = -35.7%; 95% CI = -39.5, -31.8). CONCLUSIONS For low-risk women, both scenarios result in safe outcomes for mothers and babies. However, fewer operative deliveries and medical resources were used in collaborative care.

A DECLINE IN MYOMETRIAL NITRIC OXIDE SYNTHASE EXPRESSION IS ASSOCIATED WITH LABOR AND DELIVERY

Abstract—Altered angiogenesis and insulin resistance, which are intimately related at a molecular level, characterize preeclampsia. To test if an epidemiological interaction exists between these two alterations, we performed a nested case-control study of 28 women who developed preeclampsia and 57 contemporaneous controls. Serum samples at 12 weeks of gestation were measured for sex hormone binding globulin (SHBG; low levels correlate with insulin resistance) and placental growth factor (PlGF; a proangiogenic molecule). Compared with controls, women who developed preeclampsia had lower serum levels of SHBG (208±116 versus 256±101 nmol/L, P =0.05) and PlGF (16±14 versus 67±150 pg/mL, P <0.001), and in multivariable analysis, women with serum levels of PlGF ≤20 pg/mL had an increased risk of developing preeclampsia (odds ratio [OR] 7.6, 95% CI 1.4 to 38.4). Stratified by levels of serum SHBG (≤175 versus >175 mg/dL), women with low levels of SHBG and PlGF had a 25.5-fold increased risk of developing preeclampsia (P =0.10), compared with 1.8 (P =0.38) among women with high levels of SHBG and low levels of PlGF. Formal testing for interaction (PlGF×SHBG) was significant (P =0.02). In a model with 3 (n−1) interaction terms (high PlGF and high SHBG, reference), the risk for developing preeclampsia was as follows: low PlGF and low SHBG, OR 15.1, 95% CI 1.7 to 134.9; high PlGF and low SHBG, OR 4.1, 95% CI 0.45 to 38.2; low PlGF and high SHBG, OR 8.7, 95% CI 1.2 to 60.3. Altered angiogenesis and insulin resistance are additive insults that lead to preeclampsia.

The clinical utility of serum uric acid measurements in hypertensive diseases of pregnancy.

The mechanisms that maintain relative uterine quiescence during pregnancy remain largely unknown. A possible role for nitric oxide has recently emerged, however, the expression of nitric oxide synthase within human myometrium at midgestation, a time when the uterus is normally quiescent, has not been investigated. The purpose of this study was to identify cell types in human myometrium that contain inducible nitric oxide synthase (iNOS), and to examine changes in its expression during pregnancy and labor. We found that iNOS is expressed in smooth muscle cells of pregnant myometrium. Expression of iNOS was highest in myometrium of preterm not-in-labor patients. At term, iNOS expression fell by 75%, and was barely detectable in preterm in-labor or term in-labor specimens. There was no staining in the myocytes of nonpregnant myometrium. Western blotting also revealed a similar pattern of changes in iNOS expression. In summary, iNOS expression in the myocytes of human myometrium is increased greatly during pregnancy, and declines towards term or with labor. Significantly, preterm inlabor patients also had a large decline in iNOS expression. These data suggest that changes in myometrial iNOS expression may participate in the regulation of uterine activity during human pregnancy.

Hirschsprung's disease: Associated abnormalities and demography

OBJECTIVE Our purpose was to evaluate the clinical utility of serum uric acid measurements in the hypertensive diseases of pregnancy. STUDY DESIGN We performed a nested case-control study to assess the clinical utility of serum uric acid measurements in women with hypertensive diseases of pregnancy. We identified 344 women who had serum uric acid measurements at term and categorized them into five diagnostic groups according to definitions of hypertensive diseases in pregnancy published by the National Working Group on Hypertension in Pregnancy: transient hypertension of pregnancy (n = 69), preeclampsia (n = 130), chronic hypertension (n = 23), chronic hypertension with superimposed preeclampsia (n = 29), and normal (n = 93). We compared the mean uric acid concentration for each group with use of a one-way analysis of variance and Scheffes post hoc test and calculated the sensitivities and specificities in diagnosing preeclampsia as well as the likelihood ratios for serum uric acid values of 5.5, 6.0, and 6.5 mg/dl. We also examined the correlation between serum uric acid levels and several clinical outcome measures in women with hypertensive diseases of pregnancy. RESULTS The mean serum uric acid values for women with preeclampsia (6.2 +/- 1.4 mg/dl) and transient hypertension (5.6 +/- 1.7 mg/dl) were significantly higher than those of controls (4.3 +/- 0.8 mg/dl, p < 0.05). The difference in mean serum uric acid values between women with chronic hypertension (4.9 +/- 1.0 mg/dl) and superimposed preeclampsia (5.8 +/- 1.4 mg/dl) were not statistically significant. The likelihood ratio of having preeclampsia with a serum uric acid value of 5.5 mg/dl was 1.41 in gestational hypertension of pregnancy and 2.5 in chronic hypertension. With use of a receiver-operator characteristic curve, we were unable to identify a serum uric acid value that could be used to differentiate various hypertensive diseases of pregnancy. There was a weak correlation between serum uric acid values and several clinical outcome measures of preeclampsia (r = 0.06 to 0.26). CONCLUSION Although mean serum uric acid values are elevated in women with preeclampsia, the clinical utility of serum uric acid values in differentiating various hypertensive diseases of pregnancy appears to be limited. In the setting of chronic hypertension, however, a serum uric acid level of > or = 5.5 mg/dl could identify women with an increased likelihood of having superimposed preeclampsia.