What Is New in Cesarean Delivery?: Best Articles From the Past Year.

This month we focus on current research in cesarean delivery. Dr. Hansen discusses eight recent publications, which are concluded with a "bottom-line" that is the take-home message. A complete reference for each can be found on on this page along with direct links to abstracts.

The use of digital peripheral artery tonometry to detect endothelial dysfunction in pregnant women who smoke.

OBJECTIVE: We hypothesized that, as has been shown outside of pregnancy, endothelial dysfunction would be seen in a dose-dependent fashion among women who smoke in the midtrimester of pregnancy. STUDY DESIGN: Endothelial function in women with singleton pregnancies between 16 and 23 weeks was analyzed utilizing the Endo-PAT2000 device (Itamar Medical Ltd., Caesarea, Israel) and expressed as a reactive hyperemia ratio (RHI). Serum was drawn to check cotinine and high-sensitivity C-reactive protein (CRP) levels. SAS 9.2 (SAS Institute, Cary, NC) was used to perform statistical tests including Student t test, analysis of variance, Fisher exact test, and Pearson coefficient. RESULTS: Endothelial function was noninvasively examined in 29 smokers and 31 nonsmokers. Demographics including age, race, and parity were similar between groups. Mean RHI was not significantly different between smokers and nonsmokers (1.43 ± 0.32 versus 1.53 ± 0.39, p = 0.27). No correlation was noted when cotinine values were plotted against RHI or CRP values in smokers (rho = 0.24, p = 0.21 and rho = 0.26, p = 0.18, respectively). RHI did correlate with diastolic blood pressure (rho = -0.40, p = 0.002), systolic blood pressure (rho = -0.35, p = 0.006), and heart rate (rho = -0.37, p = 0.004). CONCLUSION: We did not find an association between smoking status and endothelial dysfunction in the midtrimester utilizing a noninvasive methodology.

Up-regulation of oxytocin receptor expression at term is related to maternal body mass index.

BACKGROUND: The likelihood of cesarean is in part related to maternal body mass index (BMI). Myometrial changes may be responsible. METHODS: Myometrial biopsies were collected from the upper edge of the hysterotomy from women undergoing scheduled cesarean with term, singleton gestations. Oxytocin receptor and connexin-43 mRNA protein expression was quantified with real-time polymerase chain reaction and Western blot. RESULTS: Twenty subjects were recruited: 13 repeat and 7 primary cesareans. Oxytocin receptor mRNA was associated with BMI among women undergoing primary (r = 0.75; p = 0.05) but not repeat cesarean (p > 0.05). Controlling for gestational age, this association strengthened (p = 0.004). Receptor protein expression showed a linear correlation with BMI in the primary cesarean group (p = 0.002). Connexin-43 mRNA expression was not related to BMI in women undergoing primary (r = -0.14, p = 0.76) or repeat (r = -0.01, p = 0.86) cesarean. CONCLUSIONS: Oxytocin receptor, but not connexin-43, expression is related to BMI, suggesting an alteration in oxytocin receptor expression or function related to obesity.

Headache and neurological disease in pregnancy.

A review of the approach in pregnancy to a very commonly encountered neurological disorder (headache), along with less commonly encountered neurological entities that none the less deserve the obstetrician's attention. Definitions of specific disorders and differential diagnoses are reviewed, along with treatment options and pregnancy-associated morbidities. Headache is reviewed first including the common primary headaches migraine and tension-type headache. The disabling neurological disorders-multiple sclerosis, cerebral palsy, and spinal cord injury are grouped due to common morbidities affecting pregnancy. Finally, Bell palsy is also reviewed.

Extreme morbid obesity and labor outcome in nulliparous women at term.

We examined the prevalence of cesarean delivery (CD) among women with morbid obesity and extreme morbid obesity. Using Kentucky birth certificate data, a cross-sectional analysis of nulliparous singleton gestations at term was performed. We examined the prevalence of CD by body mass index (BMI; in kg/m2) using the National Institutes of Health/World Health Organization schema and a modified schema that separates extreme morbid obesity (BMI ≥ 50) from morbid obesity (BMI ≥ 40 to < 50). Bivariate and multivariate analyses were performed. Multivariate modeling controlled for maternal age, estimated gestational age, birth weight, diabetes, and hypertensive disorders. Overall, 83,278 deliveries were analyzed. CD was most common among women with a prepregnancy BMI ≥ 50 (56.1%, 95% confidence interval 50.9 to 61.4%). Extreme morbid obesity was most strongly associated with CD (adjusted odds ratio 4.99, 95% confidence interval 4.00 to 6.22). Labor augmentation decreased the likelihood of CD among women with extreme morbid obesity, but this failed to reach statistical significance. We speculate a qualitative or quantitative deficiency in the hormonal regulation of labor exists in the morbidly obese parturient. More research is needed to better understand the influence of morbid obesity on labor.

Violence against women and postpartum depression.

BACKGROUND: Violence against women (VAW), including intimate partner violence (IPV) in its various forms (sexual, physical, or stalking), and childhood violence (sexual or physical) are common and are associated with depressive symptoms. We examined the association between these violence exposures and self-reported history of postpartum depression (PPD). METHODS: Women from the Kentucky Women's Health Registry (KWHR) who reported at least one live birth were included in this study. Individual IPV and child abuse histories were examined for association with self-reported history of PPD. Multivariate regression analysis estimated adjusted risk ratios (aRR) and 95% confidence intervals (95% CI), controlling for age, obstetrical history, and substance abuse history. RESULTS: The 5380 women in the KWHR reporting at least one live birth were included in this study. Of these women, 2508 (46.6%) reported a history of any VAW. A history of adult VAW was associated with a history of PPD (aRR 1.48, 95% CI 1.12-1.95). Physical IPV (aRR 1.48, 95% CI 1.12-1.95) and stalking IPV (aRR 1.39, 95% CI1.03-1.87) were individually associated with PPD. Other types of violence were not individually associated with a history of PPD. The strength of association increased with each additional type of violence experienced (aRR1.17, 95% CI 1.06-1.30). CONCLUSIONS: Adult VAW is associated with self-reported history of PPD. With an increase in the number of types of abuse experienced, this association became stronger. Our findings highlight the need for thorough VAW screening in obstetrical populations.

Factors associated with substance use during pregnancy: results from a national sample.

OBJECTIVE: To examine the prevalence and correlates of substance use during pregnancy among women in the United States. METHODS: We analyzed data from pregnant (n=1800) and non-pregnant women (n=37,527) aged 15-44 years who participated in the 2002 or 2003 National Survey on Drug Use and Health, a nationally representative epidemiologic survey. Study variables included demographics, any substance use in the prior 30 days, and possible current psychopathology. Data were analyzed using weighted chi-square and multiple logistic regressions that accounted for the complex survey design. RESULTS: The overall prevalence of any past month substance use during pregnancy was 25.8%; the prevalence rates of past month illicit drug, cigarette and alcohol use were 4.7%, 18.9% and 10%, respectively. Compared to the prevalence of substance use among women in their first trimester, use was significantly lower among women in their second or third trimesters. Women who reported using substances during pregnancy were significantly more likely to meet the criteria for possible current psychopathology and be White. Additionally, women who were employed, married, and in their second or third trimester compared to the first were significantly less likely to have used any substance during pregnancy, adjusting for age, ethnicity and income. CONCLUSIONS: Although the prevalence of substance use among pregnant women was significantly lower than non-pregnant women, some groups of women remain vulnerable to continued use, including those who are unemployed, unmarried, and experiencing possible current psychopathology. Prevention and intervention programs aimed at high-risk populations are warranted to reduce the deleterious effects of substance use on pregnancy outcomes.

Sonographic findings of trisomy 18 in the second trimester of pregnancy.

OBJECTIVE: The purpose of this study was to examine the sonographic findings in fetuses with trisomy 18 in the second trimester of pregnancy. METHODS: A retrospective review of the cytogenetic laboratory databases at 6 tertiary referral centers identified all cases of trisomy 18. The prenatal sonographic studies in fetuses at 15 to 21 weeks' gestation, done before invasive testing for the karyotype, were reviewed for anatomic and biometric findings. We defined abnormal fetal biometric findings as a biometric measurement (biparietal diameter, abdominal circumference, or femur length) below the fifth percentile in the second trimester. RESULTS: Of 98 fetuses with trisomy 18, 95 (97%) were detected sonographically; an anomaly was found in 92 (94%). A biometric measurement below the fifth percentile was noted in 50 (51%). Cardiac (63%) and central nervous system (34%) anomalies were most frequently detected. Although choroid plexus cysts were commonly seen, no fetuses with trisomy 18 and isolated choroid plexus cysts were found. CONCLUSIONS: Targeted sonography identified abnormal fetal anatomy or abnormal biometric findings in 97% of fetuses with trisomy 18 in the second trimester. A biometric measurement below the fifth percentile was noted in half of the cases in the second trimester.

The yeast connection: is Candida linked to breastfeeding associated pain?

OBJECTIVE: The objective of the study was to determine whether the isolation of Candida from breastfeeding women is associated with self-reported pain. STUDY DESIGN: A prospective cohort study was conducted from May 2004 to July 2006. Ninety-eight breastfeeding women were enrolled: 20 women reported breastfeeding associated pain, and 78 women were asymptomatic. Cultures were obtained from breast milk, areolae, and infants' oropharynx. RESULTS: Six of the 20 symptomatic women had breast milk cultures positive for yeast, compared with 6 of 78 controls (30% vs 7.7%, P = .015). Among the 12 women from whom yeast was isolated, 11 grew Candida albicans. Incidence of Staphylococcus aureus isolation did not differ significantly between groups (5 of 20 vs 15 of 78, P > .05). CONCLUSION: C. albicans is found more often in breastfeeding mothers who report pain as compared with asymptomatic breastfeeding mothers. Further studies, including treatment trials, are needed to determine whether Candida plays an etiologic role in breastfeeding associated pain.

Sonographic detection of trisomy 13 in the first and second trimesters of pregnancy.

OBJECTIVE: The purpose of this study was to examine sonographic findings in fetuses with trisomy 13. METHODS: A retrospective review of the cytogenetic laboratory databases at 6 tertiary referral centers identified all cases of trisomy 13. The prenatal sonographic studies in fetuses of less than 22 weeks' gestation, done before invasive testing for karyotype, were reviewed for anatomic and biometric findings. We defined abnormal fetal biometric findings as a biometric measurement (biparietal diameter, abdominal circumference, or femur length) below the fifth percentile in the second trimester. RESULTS: There were 8 cases of trisomy 13 found in the first trimester and 54 cases found in the second trimester, a total of 62 in all. In the first trimester, 6 of 8 had an anomaly identified (4 with cystic hygroma). In the second trimester, 49 of 54 were identified by sonography; 45 had an anomaly, and 4 had an abnormal fetal biometric measurement without an anomaly. The 5 missed diagnoses had early gestational age (<17 weeks; n = 3) or an inadequate survey secondary to poor visualization. Overall, 22 of 54 fetuses with trisomy 13 had an abnormal biometric measurement. The most common anomalies detected in the second trimester were heart defects (n = 34), central nervous system anomalies (n = 30), facial clefts (n = 19), abnormal hands (n = 13), and genitourinary anomalies (n = 9). CONCLUSIONS: Targeted sonography identified abnormal fetal anatomy or abnormal biometric measurements in 95% of fetuses with trisomy 13 in the second trimester after 17 weeks' gestation. A biometric measurement below the fifth percentile was noted in nearly half of cases in the second trimester.

Should we treat periodontal disease during gestation to improve pregnancy outcomes?

Until recently many physicians in the United States including obstetrician gynecologists have been relatively unconcerned with oral health. During most physical examinations, the oral cavity is given only a rudimentary examination. With the recognition of the oral-systemic health care link, physicians have been keenly interested in the findings from their dental colleagues in periodontal medicine which have convincingly linked periodontal disease with such diverse systemic health complications as aging, Alzheimer disease, cardiovascular disease, diabetes, and also pregnancy complications including low birth weight, preterm delivery, preeclampsia, and early pregnancy loss. Intervention trials designed to improve oral health during pregnancy have proven to be safe; however, the outcomes have been inconsistent. Further studies will be required to determine the nature of the association and the optimal timing and efficacy of intervention.

Metoclopramide effect on breastfeeding the preterm infant: a randomized trial.

OBJECTIVE: To investigate the effect of metoclopramide on breast milk volume and duration of breastfeeding in women delivering preterm. METHODS: Women who planned to breastfeed and delivered between 23 and 34 weeks of gestation were eligible to participate in this randomized, double-blind, placebo-controlled study. Women were randomized to receive 10 mg of metoclopramide or placebo 3 times a day for 10 days, starting within 96 hours of birth. Breastfeeding education was standardized for all women. Mothers recorded the volume of breast milk expressed at each pumping for 17 days. Duration of breastfeeding was measured by monthly follow-up phone calls to each subject. RESULTS: Sixty-nine women were enrolled and 57 (82%) women completed the study: 28 in the metoclopramide group and 29 in the placebo group. The 2 groups were similar in age, education, ethnicity, gestational age, and marital status. There was no significant difference between breast milk volumes in the metoclopramide and placebo groups at each of the 17 days of the study (P = .26 to .98; test for mean metoclopramide effect P = .80). There was no significant difference between groups in duration of breastfeeding, with a median of 8.8 weeks, an interquartile range of 3.4 to 12.0 weeks for the metoclopramide group and a median of 8.6 weeks, and an interquartile range of 5.6 to 16.9 weeks for the placebo group (P = .09). CONCLUSION: Metoclopramide did not improve breast milk volume or duration of breastfeeding in this population of women. Regardless of therapy received, breastfeeding duration in this study of preterm mothers was poor. LEVEL OF EVIDENCE: I.

Attitudes of faculty and students toward case-based learning in the third-year obstetrics and gynecology clerkship.

OBJECTIVE: This study was undertaken to compare the attitudes of faculty and medical students toward case-based learning and lecture format during the obstetrics and gynecology clerkship. STUDY DESIGN: For this prospective comparative study, student presentations were alternately assigned to traditional lecture- or case-based format every 6 weeks. Presentations were made to other students and a single faculty. A total of 31 faculty members, 30 student presenters, and 122 student participants completed evaluations. Teaching methods were compared. RESULTS Faculty members favored lecture format over case-based learning for "attentiveness and interaction of the group" (3.9 vs 4.5, P < .018) and for "meeting the objectives" (3.7 vs 4.5, P < .002). Student participants favored case-based learning in "understanding the relationship between knowledge and clinical practice" (4.34 vs 4.06, P < .05) and "enjoyed" (4.34 vs 3.90, P < .008). Student presenters showed no differences between groups. CONCLUSION: Faculty favored lecture format whereas student participants favored a case-based presentation. Student presenters were comfortable with both formats.

Pseudoaneurysm of the uterine artery requiring bilateral uterine artery embolization.

OBJECTIVE: To report a case of uterine artery pseudoaneurysm which initially failed unilateral uterine artery embolization that subsequently responded to bilateral embolization. DESIGN: A case report. SETTING: University hospital. PATIENT(S): 32-year-old G(2) P(1) female. INTERVENTION(S): Left uterine artery embolization followed by right uterine artery embolization 1 day later. MAIN OUTCOME MEASURE(S): Vaginal bleeding, hemoglobin. RESULTS: Unilateral uterine artery embolization failed to control vaginal bleeding. Repeat embolization of the contralateral side was successful. CONCLUSIONS: Uterine artery embolization is an effective method of treating delayed postpartum hemorrhage secondary to a pseudoaneurysm of the uterine artery.

Prenatal diagnosis of Apert syndrome.

OBJECTIVE: The role of the human fibroblast growth factor receptor (FGFR) gene family in current prenatal diagnosis and management of craniosynostosis syndromes and skeletal dysplasias is discussed. METHOD: We present the antenatal ultrasound findings, diagnosis, and management of 2 cases of Apert syndrome before and after molecular prenatal diagnosis was available. RESULTS AND CONCLUSION: Discovery of mutations in FGFR genes now allows the definitive antenatal diagnosis of Apert syndrome, other craniosynostosis syndromes, and skeletal dysplasias.

Detection of cesarean scars by transvaginal ultrasound.

OBJECTIVE: To assess the ability of transvaginal ultrasound to detect cesarean scars and their defects in the nonpregnant state. METHODS: Asymptomatic, parous volunteers underwent transvaginal ultrasound of the cervix, uterus, and adnexa. Uterine measurements, the presence or absence of a cesarean scar, and the presence of a scar defect, defined as fluid within the scar, were recorded. All subjects completed a self-report questionnaire regarding obstetric history. Sonographers and investigators were blinded to subject history. RESULTS: A total of 70 subjects were enrolled. Of these, 38 women had a prior vaginal delivery and 32 women a prior cesarean delivery. One woman with a bicornuate uterus and three cesarean deliveries was excluded from data analysis. Real-time transvaginal ultrasound proved 100% sensitive (exact 95% confidence interval [CI] 88.8, 100) and 100% specific (exact 95% CI 90.7, 100). Stored image review had a sensitivity of 87% (exact 95% CI 70.2, 96.4) and a specificity of 100% (exact 95% CI 90.7, 100). Fluid was visualized within the scars of 13 of 31 subjects (42%) with a prior cesarean delivery. All 13 were found among the 23 subjects (56%) who had labored prior to cesarean delivery. Moreover, women with cesarean scar defects had a greater number of cesarean deliveries (P <.04) than women without scar defects. CONCLUSIONS: Transvaginal ultrasound is highly accurate in detecting cesarean hysterotomy scars. Cesarean scar defect, defined by the presence of fluid within the incision site, was more common when labor preceded cesarean delivery and with multiple cesarean deliveries.

Safe prescribing practices in pregnancy and lactation.

Midwives and other health care providers face a dilemma when a pregnant woman develops a condition that usually is treated with a pharmacologic agent. Understanding of basic teratology associated with drugs as well as the FDA categorization of agents can assist professionals in recognizing which pharmaceuticals should be used or avoided. In addition to reviewing teratology, this article addresses the use of common drugs for the treatment of upper respiratory conditions, minor pain, gastrointestinal problems, psychiatric illnesses, and neurologic disorders. In each category, current evidence is presented pertaining to which agents should be recommended for pregnant women.

Placenta accreta postpartum.

BACKGROUND: Placenta accreta is the abnormal attachment of the placenta to the uterus. It occurs when the decidua basalis is either absent or incomplete. It is uncommon and most often presents with a retained placenta and hemorrhage. CASE: A 29-year-old gravida 1 had an uncomplicated antenatal course and delivery. The third stage of labor was complicated by a retained placenta necessitating manual removal. Her postpartum course was complicated by a persistent endometritis. The diagnosis of placenta accreta was made with the help of sonohysterography. CONCLUSION: Sonohysterography is a useful tool in discriminating a solid intracavitary mass from a placenta accreta postpartum.

Cystic fibrosis presenting as fetal anemia. A case report.

BACKGROUND: Cystic fibrosis in the fetus may present with meconium ileus, seen as dilated, hyperechogenic bowel on the prenatal ultrasound examination. Rarely does in utero bowel perforation occur with resulting peritoneal echogenicity, ascites or lack of bowel dilation. CASE: In a case of cystic fibrosis in a fetus, all three findings above occurred, as did anemia, most likely secondary to bleeding from perforated bowel. The anemia was detected following the finding of significantly elevated peak flow velocity in the middle cerebral artery (MCA). CONCLUSION: Fetuses with cystic fibrosis can develop anemia. MCA peak flow velocity measurements are helpful in detecting the anemia.