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REPLY We would like to thank Ds Ceyhan, Safer, and Cintosun for their interest in our article and for sharing their considerable expertise on the assessment of total body fat by bioelectrical impedance analysis (BIA). They raise several points that could have improved the precision of our measurements. They point out that ideal measurements require “.performance of the BIA at the same time of the day at all times, with no food or beverage intake for 4 hours before testing and with the bladder emptied immediately before the measurement.” They also refer to a study that indicated that the measurement of fat mass with BIA may be influenced by differences in arm length, slenderness, including arm diameter, and the relative distribution of body water (extracellular water/total body water), which may differ by ethnicity.1 They cite other limitations of the use of the only 2 available sets of equations to determine total body water from BIA2 and the conversion of total body water to fat mass in pregnant women.3 Nonetheless, as noted in the article, using these equations, we found values for total body water and fat mass similar to that found in studies that measured these variables by other techniques in pregnant women. Our study was designed to test the use of BIA in a clinical setting as a potential improvement over body mass index as an estimate of body fat. This demands a study that can be done in diverse subjects and with minimal preparation, which is not compatible with the requirements to which they have alluded. It is very likely that controlling for the factors cited by the correspondents would have improved the precision of the study. However, not using these might cause us to miss
Letters to the Editors differences but was unlikely to lead to false conclusions. Thus, we are confident that the findings we made under clinically practical conditions indicate a potential tool for future clinical studies and usage. Lindsay K. Sween, MD Louisiana State University Health Sciences Center School of Public Health New Orleans, LA Andrew D. Althouse, PhD Magee-Womens Research Institute Department of Obstetrics, Gynecology and Reproductive Sciences University of Pittsburgh Pittsburgh, PA James M. Roberts, MD Magee-Womens Research Institute Departments of Obstetrics, Gynecology and Reproductive Sciences and of Epidemiology and Clinical and Translational Research University of Pittsburgh, PA The authors report no conflict of interest.
REFERENCES 1. Deurenberg P, Deurenberg-Yap M, Schouten FJM. Validity of total and segmental impedance measurements for prediction of body composition across ethnic population groups. Eur J Clin Nutr 2002;56:214-20. 2. Lukaski HC, Siders WA, Nielsen EJ, Hall CB. Total body water in pregnancy: assessment by using bioelectrical impedance. Am J Clin Nutr 1994;59:578-85. 3. Van Raaij JM, Peek ME, Vermaat-Miedema SH, Schonk CM, Hautvast JG. New equations for estimating body fat mass in pregnancy from body density or total body water. Am J Clin Nutr 1988;48:24-9. ª 2015 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ajog.2014. 09.034
Methotrexate for ectopic pregnancy: success rates and avoidance of embryopathy TO THE EDITORS: Cohen et al1 present a welcome study of a large cohort (409) treated with methotrexate (MTX) for ectopic pregnancy (EP). They worry that the success rates were lower than previously thought. However, their success rate is a quite high 88% for human chorionic gonadotrophin (b-hCG) level 1500-2000 IU/mL and a reasonably good 65.5% for b-hCG level >4500 IU/mL, thus supporting MTX as an appropriate/preferred treatment in early nonresolving EP (in agreement with several other studies). Remarkably, 62% of women eligible for b-hCG follow-up had 15% daily decline of b-hCG and did not need treatment.1 This higher percentage may be due to different admixture true EPs and pregnancies of unknown location. National Health Service Hospitals in the UK avoid transvaginal scans before 6 weeks unless there is significant pain, and hence may have fewer pregnancies of unknown location.
A recent randomized controlled trial2 is sometimes quoted as evidence that expectant management is as effective as MTX in EP with plateauing b-hCG. It recruited a very small number of women (39 for MTX and 32 for expectant) with fairly low b-hCG levels (median SD of 535 500 IU/mL and 708 376 IU/mL, respectively) at randomization (day 4). At least in some women the b-hCG may have been already falling because the inclusion criteria were
REPLY We would like to thank Ds Ceyhan, Safer, and Cintosun for their interest in our article and for sharing their considerable expertise on the assessment of total body fat by bioelectrical impedance analysis (BIA). They raise several points that could have improved the precision of our measurements. They point out that ideal measurements require “.performance of the BIA at the same time of the day at all times, with no food or beverage intake for 4 hours before testing and with the bladder emptied immediately before the measurement.” They also refer to a study that indicated that the measurement of fat mass with BIA may be influenced by differences in arm length, slenderness, including arm diameter, and the relative distribution of body water (extracellular water/total body water), which may differ by ethnicity.1 They cite other limitations of the use of the only 2 available sets of equations to determine total body water from BIA2 and the conversion of total body water to fat mass in pregnant women.3 Nonetheless, as noted in the article, using these equations, we found values for total body water and fat mass similar to that found in studies that measured these variables by other techniques in pregnant women. Our study was designed to test the use of BIA in a clinical setting as a potential improvement over body mass index as an estimate of body fat. This demands a study that can be done in diverse subjects and with minimal preparation, which is not compatible with the requirements to which they have alluded. It is very likely that controlling for the factors cited by the correspondents would have improved the precision of the study. However, not using these might cause us to miss
Letters to the Editors differences but was unlikely to lead to false conclusions. Thus, we are confident that the findings we made under clinically practical conditions indicate a potential tool for future clinical studies and usage. Lindsay K. Sween, MD Louisiana State University Health Sciences Center School of Public Health New Orleans, LA Andrew D. Althouse, PhD Magee-Womens Research Institute Department of Obstetrics, Gynecology and Reproductive Sciences University of Pittsburgh Pittsburgh, PA James M. Roberts, MD Magee-Womens Research Institute Departments of Obstetrics, Gynecology and Reproductive Sciences and of Epidemiology and Clinical and Translational Research University of Pittsburgh, PA The authors report no conflict of interest.
REFERENCES 1. Deurenberg P, Deurenberg-Yap M, Schouten FJM. Validity of total and segmental impedance measurements for prediction of body composition across ethnic population groups. Eur J Clin Nutr 2002;56:214-20. 2. Lukaski HC, Siders WA, Nielsen EJ, Hall CB. Total body water in pregnancy: assessment by using bioelectrical impedance. Am J Clin Nutr 1994;59:578-85. 3. Van Raaij JM, Peek ME, Vermaat-Miedema SH, Schonk CM, Hautvast JG. New equations for estimating body fat mass in pregnancy from body density or total body water. Am J Clin Nutr 1988;48:24-9. ª 2015 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.ajog.2014. 09.034
Methotrexate for ectopic pregnancy: success rates and avoidance of embryopathy TO THE EDITORS: Cohen et al1 present a welcome study of a large cohort (409) treated with methotrexate (MTX) for ectopic pregnancy (EP). They worry that the success rates were lower than previously thought. However, their success rate is a quite high 88% for human chorionic gonadotrophin (b-hCG) level 1500-2000 IU/mL and a reasonably good 65.5% for b-hCG level >4500 IU/mL, thus supporting MTX as an appropriate/preferred treatment in early nonresolving EP (in agreement with several other studies). Remarkably, 62% of women eligible for b-hCG follow-up had 15% daily decline of b-hCG and did not need treatment.1 This higher percentage may be due to different admixture true EPs and pregnancies of unknown location. National Health Service Hospitals in the UK avoid transvaginal scans before 6 weeks unless there is significant pain, and hence may have fewer pregnancies of unknown location.
A recent randomized controlled trial2 is sometimes quoted as evidence that expectant management is as effective as MTX in EP with plateauing b-hCG. It recruited a very small number of women (39 for MTX and 32 for expectant) with fairly low b-hCG levels (median SD of 535 500 IU/mL and 708 376 IU/mL, respectively) at randomization (day 4). At least in some women the b-hCG may have been already falling because the inclusion criteria were
