Lovepreet K. Mann

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.

Use of the Learning Curve-Cumulative Summation test for quantitative and individualized assessment of competency of a surgical procedure in obstetrics and gynecology: fetoscopic laser ablation as a model

OBJECTIVE We sought to determine the learning curve (LC) for fetoscopic laser photocoagulation (FLP) as a model for the evaluation of training in surgical procedures. STUDY DESIGN A retrospective review of consecutive case series of FLP from 2 centers with 3 operators (operator I [O-I], observer trained; operator II [O-II], hands-on trained; and operator III [O-III], clinical fellow) was performed and the LC-cumulative summation (CUSUM) test was plotted. RESULTS The acceptable and unacceptable success rates for at least 1 fetus survival after FLP were set at 82% and 70%, respectively, from a systematic review. A total of 171 consecutive cases were performed by the 3 operators (O-I, 91; O-II, 49; and O-III, 31). From LC-CUSUM test O-I needed 60 procedures, O-II needed 20 procedures, and O-III needed 20 procedures to reach an acceptable performance rate for at least 1 survivor. CONCLUSION The LC-CUSUM test can be used to accurately assess the LC in a surgical procedure in obstetrics and gynecology. Hands-on trained operators exhibit a shorter LC.

Chorioamnion separation as a risk for preterm premature rupture of membranes after laser therapy for twin-twin transfusion syndrome.

OBJECTIVE: To compare the outcomes in chorioamnion membrane separation with nonchorioamnion membrane separation cases after fetoscopic laser photocoagulation of placental anastomoses for the treatment of twin to twin transfusion syndrome. METHODS: We performed a retrospective cohort study of twin to twin transfusion syndrome cases that underwent laser ablation at the Texas Childrens Fetal Center from October 2007 to March 2009. The cases were identified from our database. We excluded triplet pregnancies. Chorioamnion membrane separation was identified by ultrasound examination performed within 24 hours of intervention. Preterm premature rupture of membranes (PROM) was defined as rupture of the membranes before 34 weeks of gestation. RESULTS: Ninety-seven cases were included in the analysis; 19 (19.6%) had chorioamnion membrane separation. There were no significant differences in preoperative and intraoperative variables, except for a lower recipient maximum vertical pocket (10.3±2.1 compared with 12.6±3.4; P<.01), and higher rate of iatrogenic septostomy (21% compared with 2.5%; P=.01) in the chorioamnion membrane separation group. Postoperatively, the incidence of preterm PROM was 74% in chorioamnion membrane separation group compared with 23% in the nonchorioamnion membrane separation group (relative risk 3.2, 95% confidence interval 1.9–4.4). The procedure-to-delivery interval was reduced by 20 days in the chorioamnion membrane separation group (P<.01). The neonatal survival rate was 63.2% in the chorioamnion membrane separation group compared with 84% in the nonchorioamnion membrane separation group (P=.016). CONCLUSION: A low preoperative recipient maximum vertical pocket is associated with increased risk of chorioamnion membrane separation. Postoperative chorioamnion membrane separation after laser surgery for twin to twin transfusion syndrome is a major risk factor for preterm PROM, early delivery, and an increase in perinatal mortality. LEVEL OF EVIDENCE: II

Changes in the recipient fetal Tei index in the peri‐operative period after laser photocoagulation of placental anastomoses for twin–twin transfusion syndrome

To assess serial changes in the Tei index of the recipient fetus secondary to fetoscopic laser photocoagulation of placental anastomoses (FLP) for twin‐twin transfusion syndrome (TTTS) during the peri‐operative period.

Fetal membrane patch and biomimetic adhesive coacervates as a sealant for fetoscopic defects

Iatrogenic preterm premature rupture of membranes after fetoscopic procedures affects 10-47% of patients, secondary to the non-healing nature of membranes and the separation of layers during the entry. In this study we developed an in vitro model to mimic the uterine wall-fetal membrane interface using a water column with one end sealed with human fetal membranes and poultry breast, and a defect was created with an 11 French trocar. Further, a fetal membrane patch in conjunction with multiphase adhesive coacervates modeled after the sandcastle worm bioadhesive was tested for sealing of an iatrogenic defect. The sealant withstood an additional traction of 12 g for 30-60 min and turbulence of the water column without leakage of fluid or slippage. The adhesive is non-toxic when in direct contact with human fetal membranes in an organ culture setting. A fetal membrane patch with multiphase adhesive complex coacervates may help to seal the defect and prevent iatrogenic preterm premature rupture of the membranes.

Risk factors associated with preterm delivery after fetoscopic laser ablation for twin–twin transfusion syndrome

Despite improved perinatal survival following fetoscopic laser ablation (FLA) for twin–twin transfusion syndrome (TTTS), prematurity remains an important contributor to perinatal mortality and morbidity. The objective of the study was to identify risk factors for complicated preterm delivery after FLA.

Absorbable gelatin plug does not prevent iatrogenic preterm premature rupture of membranes after fetoscopic laser surgery for twin–twin transfusion syndrome

Despite fetoscopic laser ablation (FLA) having emerged as an effective treatment for twin–twin transfusion syndrome (TTTS), major postintervention challenges, such as iatrogenic preterm premature rupture of membranes (iPPROM), remain. A chorioamniotic plug (CAP) made of absorbable gelatin sponge has been used to seal the trocar entry site in the chorioamniotic layers to promote healing and prevent iPPROM, yet the results have been equivocal. Our objective was to test the hypothesis that, following FLA for TTTS, iPPROM may be prevented by placement of an absorbable gelatin CAP.

Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

Background:Preterm premature rupture of membranes remains a major complication after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). We studied the histologic changes of fetal membranes post-FLS and investigated a possible impact of amniotic fluid (AF) dilution.Methods:Fetal membranes of 31 pregnancies that underwent FLS for TTTS were investigated histologically at delivery at different sites: trocar site of recipient sac and at distance, donor sac, and inter-twin membrane.Results:The trocar insertion site on the recipient sac showed no signs of histologic hallmarks of healing. Wide-spread alteration in collagen organization and higher apoptotic index in the amnion of the recipient sac which were absent in donor’s and reference membranes. To explain the mechanisms, we analyzed the AF composition of recipient sacs from TTTS pregnancies vs. GA-matched healthy singleton controls and found glucose, protein and lactate dehydrogenase activity were all significantly lower in TTTS sacs consistent with over-dilution of recipient’s AF (~2-fold). In-vitro exposure of healthy amniochorion to analogous dilutional stress conditions recapitulated the histologic changes and induced apoptosis and autophagy.Conclusion:Alteration in structural integrity of the recipient’s amniochorion, possibly in response to dilution stress, along with ineffective repair mechanisms may explain the increased incidence of preterm birth post-FLS.

Cerclage for cervical shortening at fetoscopic laser photocoagulation in twin-twin transfusion syndrome.

OBJECTIVE The purpose of this study was to evaluate the benefit of cervical cerclage for cervical length ≤ 25 mm at the time of fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome. STUDY DESIGN A multicenter, retrospective cohort study was conducted with 163 patients with a short cervix before FLP for twin-twin transfusion syndrome. Seventy-nine of the patients (48%) had cerclage placement at the surgeons discretion. The outcome measures that were compared were gestational age at delivery and perinatal mortality rates for patients with cerclage and those who were treated conservatively. Outcomes were evaluated with the use of comparative statistics. RESULTS There were no differences in the preoperative variables, except cerclage was performed more frequently for a cervical length of ≤ 15 mm (P < .001). There were no differences in the gestational age at delivery (28.8 ± 5.4 vs 29.1 ± 5.6 weeks with and without cerclage, respectively; P = .15); perinatal mortality rates were similar between the 2 groups. CONCLUSION The benefit of cerclage for patients with short cervix before FLP remains questionable.

Preterm prelabor rupture of membranes after fetoscopic laser surgery for twin–twin transfusion syndrome

To assess the incidence, clinical course, risk factors and outcomes of preterm prelabor rupture of membranes (PPROM) after fetoscopic laser surgery (FLS) for twin–twin transfusion syndrome (TTTS).