Homa Ahmadzia

Obstetric surgical site infections: 2 grams compared with 3 grams of cefazolin in morbidly obese women

OBJECTIVE: To estimate whether morbidly obese gravid patients were less likely to develop a surgical site infection after receiving a higher dose of preoperative prophylactic antibiotics. METHODS: A retrospective cohort study of morbidly obese pregnant women undergoing cesarean delivery was conducted at two tertiary care centers from 2008 to 2013. Exposure was defined as receiving 2 g compared with 3 g cefazolin preoperatively. Disease was defined by diagnosis of a surgical site infection using Centers for Disease Control and Prevention criteria. We estimated a sample size of 141 patients in each group for a 67% reduction (15% to 5%) in risk for a surgical site infection. RESULTS: There were 335 women included in the cohort with a median absolute weight of 310 (interquartile range 299–333) pounds. Forty-four (13.1%) women were diagnosed with a surgical site infection. There was no difference in surgical site infection among those women who received 2 g compared with 3 g cefazolin (13.1% [23/175] compared with 13.1% [21/160]; P=.996). Labor (crude odds ratio [OR] 2.31, 95% confidence interval [CI] 1.21–4.40), internal labor monitoring (OR 2.78, 1.45–5.31), blood loss greater than 1,500 mL (OR 2.15, 1.09–5.78), and staple closure (OR 2.2, 1.15–4.21) were associated with a surgical site infection among the entire cohort. After multivariable analysis, blood loss greater than 1,500 mL (adjusted OR 3.32, 1.32–8.37) and staple closure (adjusted OR 2.45, 1.19–5.02) remained associated with an increased risk for a surgical site infection, whereas 3 g cefazolin still was not associated with reduced risk for a surgical site infection (adjusted OR 1.33, 0.64–2.74). CONCLUSION: In our multicenter retrospective cohort study, preoperative 3 g cefazolin prophylaxis administered to morbidly obese gravid patients did not reduce surgical site infections. LEVEL OF EVIDENCE: III

Fetal intracranial hemorrhage: role of fetal MRI

To date, prenatal diagnosis of intracranial hemorrhage (ICH) is mainly based on ultrasound (US) findings rather than magnetic resonance imaging (MRI). We aimed to investigate the role of MRI in the diagnosis of fetal ICH among pregnancies referred to fetal MRI and to characterize the topography of fetal ICH using MRI.

Can we improve the gestation-adjusted projection (GAP) method for prediction of birth weight in morbidly obese women?

Abstract Objective: The gestation-adjusted projection (GAP) is a method to predict birthweight using population birth data and third trimester ultrasound fetal weight. This method usually utilizes population birth weight data from almost 40 years ago. In 2011, a large cohort of racially diverse infants across the US was included to validate updated birth curves. Our objective was to determine if the updated data would improve the accuracy of the GAP method during the third trimester among obese women. Methods: This secondary analysis of a cohort study included singleton pregnancies of obese women who had fetal growth assessment(s) in the third trimester. The first subgroup (N = 235) included women with a BMI >40 kg/m2 who had ultrasounds during 30 + 0–35 + 0 weeks (EARLY) and greater than 35 + 0 weeks (LATE). The second subgroup (N = 431) included women with a BMI 30–35, 40–50, or >50 kg/m2 who had an ultrasound during 34 + 0–36 + 6 weeks. Mean absolute percent error was calculated for all GAP methods and compared using paired t-tests. Sensitivity, specificity, and area under the curve for diagnosis of birth weight >4000 grams were also estimated for each GAP method. Results: The mean absolute percent error for the first subgroup (N = 235) using historical population birth weights was 7.4–7.9%. After using updated population birth weight curves using all neonates, the mean absolute percent error for the first subgroup ranged between 7.6 and 9.4%. GAP predictions using all neonates, as well as male and female-specific birth data compared to the historical population data during both the EARLY and LATE periods were significantly worse (p < .01). The mean absolute percent error for the second subgroup (N = 431) using historical population birth weights ranged from 7.2 to 7.9%. The absolute percent error using gender-specific compared to historical data was significant in the BMI 30–35 group (male 8.1% versus historical 7.6%, p < .01, female 8.1% versus historical 7.6%, p < .01). The differences in absolute percent error between historical and updated population data became less evident in the BMI 40–50 and >50-kg/m2 groups (p = .05 and p = .15, respectively) though still overall performed worse with the updated data. Conclusions: Prediction of birth weight using the GAP method does not seem to be improved among obese women after using updated population data. Alternatively, modeling techniques may need to be applied to improve the accuracy of the GAP method.

Using antifibrinolytics in the peripartum period – concern for a hypercoagulable effect?

INTRODUCTION Although antifibrinolytic agents are used to prevent and treat hemorrhage, there are concerns about a potential increased risk for peripartum venous thromboembolism. We sought to determine the impact of tranexamic acid and ɛ-aminocaproic acid on in vitro clotting properties in pregnancy. METHODS Blood samples were obtained from healthy pregnant, obese, and preeclamptic pregnant women (n = 10 in each group) prior to delivery as well as from healthy non-pregnant controls (n = 10). Maximum clot firmness (MCF) and clotting time (CT) were measured using rotation thromboelastometry in the presence of tranexamic acid (3, 30, or 300 μg/mL) or ɛ-aminocaproic acid (30, 300, or 3000 μg/mL). ANOVA and regression analyses were performed. RESULTS Mean whole blood MCF was significantly higher in healthy pregnant vs. non-pregnant women (66.5 vs. 57.5 mm, p < 0.001). Among healthy pregnant women, there was no significant difference between mean MCF (whole blood alone, and with increasing tranexamic acid doses = 66.5, 66.1, 66.4, 66.3 mm, respectively; p = 0.25) or mean CT (409, 412, 420, 424 sec; p = 0.30) after addition of tranexamic acid. Similar results were found using ɛ-aminocaproic acid. Preeclamptic women had a higher mean MCF after the addition of ɛ-aminocaproic acid and tranexamic acid (p = 0.05 and p = 0.04, respectively) compared to whole blood alone. CONCLUSIONS Pregnancy is a hypercoagulable state, as reflected by an increased MCF compared to non-pregnant women. Addition of antifibrinolytic therapy in vitro does not appear to increase MCF or CT for non-pregnant, pregnant, and obese women. Whether antifibrinolytics are safe in preeclampsia may require further study.

Obstetric hemorrhage survey: Attitudes and practices of maternal-fetal medicine fellows

OBJECTIVE To evaluate experiences related to obstetric hemorrhage and suspected abnormal placentation among first year maternal-fetal medicine fellows. STUDY DESIGN A cross-sectional anonymous survey was administered at the Society for Maternal-Fetal Medicine fellow retreat in March 2013. Fellows were asked about management strategies that reflected both their individual and institutional practices. RESULTS There was a 56% response rate (55/98). In cases of postpartum hemorrhage due to uterine atony, there was variable use of the uterine tamponade device. The median incremental time for balloon deflation was every 5 hours (IQR = 2-12). Compared to the east coast, fellows from the west coast performed more hysterectomies (mean±SD; 2.9±2.4 vs. 1.2±1.2, p = 0.004). During a peripartum hysterectomy, 29% of fellows used a handheld cautery device such as Ligasure® or Gyrus®. Fifty-six percent responded that their institution never recommend planned delayed hysterectomies for abnormal placental implantation. CONCLUSION There is wide variation in practice among first year maternal-fetal medicine fellows in management of peripartum hysterectomy and postpartum hemorrhage.

Survey of Peripartum Hysterectomy Experiences: Anticipated, Unplanned, or Averted

INTRODUCTION: To evaluate the experiences related to peripartum hysterectomy among first-year maternal-fetal medicine Fellows in the United States. METHODS: A cross-sectional anonymous survey was administered at the Society for Maternal-Fetal Medicine first-year Fellow annual retreat in March 2013. Fellows were asked about prior experiences, management strategies for suspected abnormal placentation, uterine tamponade devices, and antifibrinolytic agents. Statistical analysis was performed using univariate and bivariate methods. RESULTS: There was a 56% response rate (55/99) for completed surveys. Compared with the East Coast, Fellows from West Coast programs have performed more hysterectomies (mean values with standard deviations 2.9±2.4 compared with 1.2±1.2, P=.004). Only 25% of responders felt adequately trained to perform a peripartum hysterectomy as the supervising physician. Handheld cautery devices such as the Ligasure or Gyrus were used by 29% during a peripartum hysterectomy. In situations in which preoperative ultrasonography showed abnormal placentation, only 16% always obtained a preoperative magnetic resonance image. Sixty-five percent responded that their institution never recommend planned delayed hysterectomies. In cases of postpartum hemorrhage resulting from uterine atony, there was a wide variation in the use and management of uterine balloon tamponade devices. The median incremental time for balloon deflation was every 5 hours (interquartile range 2–12) by 25% (interquartile range 20–50). CONCLUSIONS: There is wide variation in practice among first-year maternal-fetal medicine Fellows in management of anticipated, unplanned, or averted peripartum hysterectomies. Given the serious morbidity and mortality associated with these clinical situations, development of management guidelines is warranted.