J. Christopher Glantz

Vertical skin incisions and wound complications in the obese parturient

OBJECTIVE To examine the relationship between the type of skin incision and postoperative wound complications in an obese population. METHODS A hospital-based perinatal database was used to identify women with a body mass index (BMI) of greater than 35 undergoing their first cesarean delivery. Hospital and outpatient medical records were reviewed for the following variables: age, insurance status, BMI, gestational age at delivery, birth weight, smoking history, prior abdominal surgery, existing comorbidities, preoperative hematocrit, chorioamnionitis, duration of labor and membrane rupture, dilation at time of cesarean delivery, type of skin and uterine incision, estimated blood loss, operative time, antibiotic prophylaxis, use of subcutaneous drains or sutures, endometritis, and length of stay. The primary outcome variable was any wound complication requiring opening the incision. Multiple logistic regression analysis was completed to determine which of these factors contributed to the incidence of wound complications. RESULTS From 1994 to 2000, 239 women with a BMI greater than 35 undergoing a primary cesarean delivery were identified. The overall incidence of wound complications in this group of severely obese patients was 12.1%. Factors associated with wound complications included vertical skin incisions (odds ratio [OR] 12.4, P < .001) and endometritis (OR 3.4, P = .03). A high preoperative hematocrit was protective (OR .87, P = .03). No other factors were found to impact wound complications. CONCLUSION Primary cesarean delivery in the severely obese parturient has a high incidence of wound complications. Our data indicate that a vertical skin incision is associated with a higher rate of wound complications than a transverse incision.

Term Labor Induction Compared With Expectant Management

OBJECTIVE: To determine whether changing the definition of the group to which induction is being compared (ie, noninduced delivering during the same week as those induced compared with two definitions of expectant management) changes the association of labor induction and increased cesarean risk. METHODS: A New York State birth-certificate database was used to estimate odds ratios for cesarean delivery associated with labor induction at term. The analyses used three definitions of controls: cesarean delivery after induction compared with after spontaneous labor by week (week-to-week), induction at a given gestation age compared with expectant management of all other women after gestational age (all above), or induction at a given gestational age compared with expectant management of all other women at or after that gestational age (at or above). Chi-square logistic regression was used for comparisons and adjustment for possible confounders. RESULTS: All variations of comparison groups were associated with increased unadjusted cesarean risk after induction, although not after 39 weeks in the all-above group. After adjustment, increased risk persisted from 37 to 41 weeks using the week-to-week group and from 38 to 41 weeks in the at-or-above group (odds ratios 1.24 to 1.45) but was no longer significant in the all-above group. The excess cesarean delivery risk associated with labor induction is between 1 and 2 per 25 inductions. CONCLUSION: Labor induction is associated with increased cesarean risk whether using a week-to-week comparison group or an expectant group that includes women the same week or beyond that of the index induction, even after adjustment for parity, high-risk factors, and demographic variables. Although the magnitude of increased risk for a given woman undergoing induction is not large, women nonetheless should be informed of this increased risk. LEVEL OF EVIDENCE: II

Protein/creatinine ratio in preeclampsia: A systematic review

OBJECTIVE: To estimate the accuracy of the protein/creatinine ratio in predicting 300 mg of protein in 24-hour urine collection in pregnant patients with suspected preeclampsia. DATA SOURCES: Articles were identified through electronic databases (MEDLINE, CINHAL, and Cochrane) using the terms “preeclampsia,” “protein/creatinine ratio,” and “diagnosis,” during the period January 1966 to October 2007. The relevant citations were hand searched. METHODS OF STUDY SELECTION: Included studies evaluated patients for suspected preeclampsia with a 24-hour urine sample and a protein/creatinine ratio. Only English-language articles were included. Studies including patients with only chronic illness such as chronic hypertension, diabetes mellitus, or renal impairment were excluded. Using the Quality Assessment of Diagnostic Accuracy Studies questionnaire, we created group 1 satisfying all the required criteria and group 2 not satisfying all of it. Two researchers independently extracted the accuracy data. A graph comparing six receiver operating characteristic curves was plotted. TABULATION, INTEGRATION, AND RESULTS: Twenty-one studies were identified, but only seven met our inclusion criteria (1,717 total patients). Group 1, with three studies, had 510 patients. The studies evaluated different cut points for positivity of protein/creatinine ratio from 130 mg/g to 700 mg/g. For protein/creatinine ratio 130–150 mg/g, sensitivity ranged from 90–99%, and specificity ranged from 33–65%; for protein/creatinine ratio 300 mg/g, sensitivity ranged from 81–98% and specificity ranged from 52–99%; for protein/creatinine ratio 600–700mg/g, sensitivity ranged from 85–87%, and specificity ranged from 96–97%. CONCLUSION: Random protein/creatinine ratio determinations are helpful primarily when they are below 130–150 mg/g, in that 300 mg or more proteinuria is unlikely below this threshold. Midrange protein/creatinine ratio (300 mg/g) has poor sensitivity and specificity, requiring a full 24-hour urine for accurate results. Higher thresholds have not been adequately studied.

Cesarean delivery risk adjustment for regional interhospital comparisons.

OBJECTIVE The aim of this study was to determine the effect of adjustment for patient population mix on observed, expected, and standardized cesarean delivery rates in regional hospitals. STUDY DESIGN Multiple logistic regression was applied to a large regional perinatal database comprising 16 hospitals. Variables significantly associated with cesarean delivery were used to calculate cesarean delivery probabilities for individual patients. Probabilities were summed across hospitals to derive expected hospital cesarean delivery rates. A standardized rate for each hospital was then calculated by dividing the observed rate by the expected rate and multiplying by the regional rate. RESULTS The regional cesarean delivery rate was 21.9% for 6798 women. Observed hospital rates varied from 17.1% to 39.2%. Twenty-two variables were associated with cesarean delivery. Expected cesarean delivery rates ranged from 18.1% to 26.0%. Among the 5 hospitals with the lowest observed cesarean delivery rates only 2 had rates significantly lower than those of the rest of the region, and only 1 of those 2 rates remained significantly lower after adjustment. One other hospital that had an adjusted rate significantly lower than the crude rate had not appeared statistically different from the rest of the region before standardization. Among the 5 hospitals with the highest cesarean delivery rates, 4 had rates significantly higher than the rest of the region, and 3 of them had significantly higher observed rates than expected rates. CONCLUSIONS Compared with using observed (crude) cesarean delivery rates, adjustment for differences in patient risk factor mix facilitates more accurate comparison of cesarean delivery rates among hospitals within a region.

Inflammatory cytokines and antioxidants in midtrimester amniotic fluid: correlation with pregnancy outcome

OBJECTIVE Elevated interleukin-6 (IL-6) level in midtrimester amniotic fluid is associated with preterm delivery. We hypothesized that, in patients with elevated IL-6, vitamin C and alpha-fetoprotein may provide protection from spontaneous preterm delivery through antioxidant functions. STUDY DESIGN Antioxidant potential of alpha-fetoprotein was assessed in vitro. Amniotic fluid was collected from a prospective cohort of patients who underwent midtrimester amniocentesis. In patients with IL-6 >600 pg/mL, alpha-fetoprotein, vitamin C, tumor necrosis factor-alpha, tumor necrosis factor receptors, and antioxidant capacity were compared between subjects with spontaneous preterm and term deliveries. RESULTS Alpha-fetoprotein demonstrated 75% the antioxidant capacity of albumin in vitro. Of 388 subjects, 73 women had elevated IL-6 levels. Among these subjects, alpha-fetoprotein, but not vitamin C, was significantly lower in 9 women with preterm birth. Antioxidant capacity correlated with vitamin C and tumor necrosis factor receptors, but not with alpha-fetoprotein or pregnancy outcome. CONCLUSION Amniotic fluid alpha-fetoprotein, but not vitamin C, may protect against preterm birth in patients with elevated midtrimester IL-6 levels.

Birth Outcomes Across Three Rural-Urban Typologies in the Finger Lakes Region of New York

PURPOSE The study is a descriptive, population-based analysis of birth outcomes in the New York State Finger Lakes region designed to determine whether perinatal outcomes differed across 3 rural typologies. METHODS Hospital birth data for the Finger Lakes region from 2006 to 2007 were used to identify births classified as low birthweight (LBW), small for gestational age (SGA), and preterm delivery (PTD). Maternal residences were defined using 3 existing ZIP code-level rural-urban typologies: Census Bureau ZIP codes, Rural-Urban Commuting Area codes, and Primary Service Areas. Within each typology, rural maternal characteristics and birth outcomes were compared to those in urban areas using multivariable logistic regression models. FINDINGS In bivariate analyses, rurality was associated with LBW and SGA for all typologies, whereas PTD was associated with residence in the Census Bureau typology only. After controlling for demographic characteristics, births to mothers in the most rural level of the Census Bureau typology and to all rural mothers in the Rural-Urban Commuting Area (RUCA) and Primary Service Area typologies were more likely to be LBW and PTD. SGA was not consistently associated with residence across typologies. CONCLUSIONS The typologies produced similar results for these outcomes, although effects were of greater magnitude in the RUCA and Primary Service Area typologies than in the Census Bureau typology. Comparison across typologies can have practical implications for researchers and policy makers interested in understanding the dynamics of rurality and birth outcomes in their regions.

Risk factors for wound complications in morbidly obese women undergoing primary cesarean delivery

Objective: To determine factors influencing separation and infectious type wound complications (WCs) in morbidly obese women undergoing primary cesarean delivery (CD). Methods: Retrospective cohort study evaluating infectious and separation WC in morbidly obese (body mass index [BMI] > 35 kg/m2) women undergoing primary CD between January 1994 and December 2008. Chi-square, Fisher’s exact and Student’s t tests used to assess associated factors; backward logistic regression to determine unadjusted and adjusted odds ratios. Results: Of 623 women, low transverse skin incisions were performed in 588 (94.4%), vertical in 35 (7%). Overall WC rate was 13.5%, which varied by incision type (vertical 45.7% vs. 11.6% transverse; p < 0.01), but not BMI class. Incision type and unscheduled CD were associated with infection risk, while incision type, BMI, race and drain use were associated with wound separation. Conclusion: In morbidly obese women both infectious and separation type WC are more common in vertical than low transverse incisions; therefore transverse should be preferred.

Significance of Echogenic Foci in the Left Ventricle of the Fetal Heart in a Low-Risk Population

Objective: To determine if there exists a significant association between prenatally detected left ventricular echogenic foci and chromosomal abnormalities. Methods: Over a 10-month period the presence of intracardiac echogenic foci was recorded on all low-risk patients referred for anatomical assessment. The study group consisted of 113 singleton fetuses and was compared to a control group with no foci. Results: Among the study group with echogenic foci, 5 chromosomal abnormalities (three trisomies) were detected. In the control group only one chromosomal abnormality was diagnosed. Conclusion: An association exists between the finding of intracardiac echogenic foci in the fetus and the presence of chromosomal abnormalities.

Cost-Effectiveness of Routine Antenatal Varicella Screening

Objective To evaluate the cost-effectiveness of routine antenatal varicella serologic screening of pregnant women with negative or indeterminate varicella histories. Methods Routine antenatal varicella screening was evaluated using a decision analytic model. Outcomes were varicella cases, deaths, and life-years. Probabilities were derived from the literature, and sensitivity analysis was performed when data were imprecise or subject to variation. The analysis was repeated to include the effect of a policy of routine screening and vaccination of all adults. Results Routine antenatal varicella screening of history-negative women was not cost-effective unless the cost of screening was decreased six-fold, varicella exposure rates were greater than 6%, or there was a greater than three-fold decrease in varicella exposure in women testing nonimmune compared with unscreened women. These results were not sensitive to alterations in varicella-zoster immunoglobulin (Ig) effectiveness, varicella communicability, rates and timing of contact reporting, costs (per case, pneumonia, and death), or serologic test performance. If performed as part of a policy of universal screening of all history-negative adults (with vaccination of the majority of those testing nonimmune), routine antenatal varicella testing became cost-effective. Conclusion Routine antenatal varicella screening of all pregnant women with negative or indeterminate varicella histories is not cost-effective. It could be cost-effective in groups of women with increased exposure risk, or if part of a policy of screening and vaccination of all adults.

Obstetrical Issues in Substance Abuse

Substance abuse complicates between 10% and 25% of pregnancies, and has been associated with increased perinatal morbidity and mortality. The mechanisms of action of certain drugs predispose to specific types of complications, but the explanations for obstetrical effects of other drugs are more obscure. It is often difficult to differentiate the effects of drugs from the socioeconomic issues surrounding the drug abuser. There is no doubt, however, that the infants of pregnant drug abusers suffer from increased risks of low birthweight, preterm delivery, possible teratogenic effects, fetal dependence and withdrawal, and possible neurobehavioral effects. Health-care providers must encourage these patients to seek prenatal care early and to continue care throughout pregnancy. With a coordinated system for antenatal monitoring and support, these risks hopefully can be decreased and the perinatal outcome improved.