Biomedical subjects

N S Whitworth

Publications and source records attributed to N S Whitworth.

At least 19 recordsLinked to original sources

PubMed2002

Ultrasound estimation of amniotic fluid volume using the largest vertical pocket containing umbilical cord: measure to or through the cord?

OBJECTIVES: The purpose of this investigation was to determine the preferable method, either measuring to the umbilical cord or through the umbilical cord to the base of the pocket, of ultrasonically estimating amniotic fluid volume. SUBJECT AND METHODS: This was a prospective study carried out in singleton pregnancies undergoing a third-trimester amniocentesis. The amniotic fluid index (AFI) and single deepest pocket (SDP) were measured prior to amniocentesis. If measured spaces contained umbilical cord, measurements were made to and through the cord. Actual amniotic fluid volume was determined by the dye-dilution technique. RESULTS: One-hundred pregnancies were evaluated. Low dye-determined volume was identified in a significantly greater number of pregnancies using the AFI to the cord (7/28, 25%) compared to through the cord (2/28, 7%) (P = 0.025). The SDP technique to the cord was superior in low volumes (2/28, 7%) vs. (0/28, 0%) through the cord (although statistical significance could not be determined because there were no low through-the-cord measurements). CONCLUSIONS: For the detection of low amniotic fluid volumes, the AFI to the cord is better than through the cord. Measurement to the cord and through the cord had similar accuracy for both the AFI and SDP techniques in normal and high dye-determined amniotic fluid volumes.

Adolescent↗

PubMed2002

Dye-dilution techniques using aminohippurate sodium: do they accurately reflect amniotic fluid volume?

OBJECTIVE: To determine whether the dye-dilution technique using aminohippurate sodium accurately measures amniotic fluid volume. METHODS: Singleton pregnancies with intact membranes undergoing a Cesarean delivery had their amniotic fluid volume assessed by the dye-dilution technique and direct measurement. RESULTS: Fifteen women were prospectively assessed. Six patients had their amniocentesis on the delivery table and nine patients at 4-24 h prior to the Cesarean delivery. The six women undergoing an amniocentesis just before delivery had good concordance between the dye-determined and direct measurement of amniotic fluid volume (r = 0.99, p = < 0.001). Among the nine women with varying times from amniocentesis to direct measurement, the correlation was not significant (r = 0.36, p = 0.08). The percentage difference between the dye-determined and directly measured amniotic fluid volume was significantly smaller in the women undergoing amniocentesis just prior to delivery (7%) than in the women with varying times from amniocentesis to delivery (37%, P < 0.001). CONCLUSION: Dye-determined amniotic fluid volume accurately reflects actual amniotic fluid volume but the dye-determined concentrations, in vivo, may undergo rapid changes.

Adolescent↗

PubMed2001

Ultrasound estimate of amniotic fluid volume: color Doppler overdiagnosis of oligohydramnios.

OBJECTIVE: To determine if concurrent use of color Doppler affects ultrasound estimates of amniotic fluid (AF) volume. METHODS: Study gravidas underwent ultrasound estimations of AF volume subjectively (visualization without measurements) and objectively (using amniotic fluid index [AFI]) and single-deepest pocket techniques, without and with concurrent color Doppler. Amniocentesis with the dye-dilution technique to measure actual AF volume was utilized for comparison. RESULTS: Sixty-seven women at a mean gestational age of 37.1 +/- 2.5 weeks were entered into this investigation between June 1999 and March 2000. Dye-determined AF volume was classified as low in 18 patients and as high in seven, with the remaining 42 within normal range. Using either ultrasound technique with color Doppler produced significantly lower estimates of AF volume (9.3 +/- 4.9) compared to those without color ([11.6 +/- 5], P <.001) for the AFI and (3.7 +/- 1.5) with color compared to those without color ([4.5 +/- 1.5], P <.003) for the single-deepest pocket. Using AFI without color identified two of 67 (3%) of the pregnancies as having low fluid compared to 14 of 67 ([21%] P =.002) using color. The increased classification of oligohydramnios with color did not accurately identify a greater number of dye-determined low volumes; instead, the AFI with color mislabeled nine pregnancies with normal fluid as low. The diagnosis of dye-determined low and high fluid volumes was not significantly different with or without color. CONCLUSION: Concurrent use of color Doppler with AFI measurements leads to the overdiagnosis of oligohydramnios.

Adolescent↗

PubMed2001

Subjective versus objective evaluation of amniotic fluid volume of pregnancies of less than 24 weeks' gestation: how can we be accurate?

This study was undertaken to compare subjective versus objective ultrasonic evaluation of amniotic fluid volume in pregnancies of less than 24 weeks' gestation. Amniotic fluid volume was subjectively (visualization without ultrasonic measurements) and objectively (visual interpretation with ultrasonic measurements) evaluated in 42 singleton pregnancies undergoing termination. The actual amniotic fluid volume was then determined using a dye-dilution technique. The women evaluated were in their mid-20s, primarily African American, and between 15 and 23 weeks' gestation. There was no significant difference in the total number of correct estimates of amniotic fluid volume when the data were stratified by level of operator experience (P = .34), ultrasonic technique (P = .33), or the combined correct subjective versus combined correct objective estimates (P = .68). We have concluded that the accuracy of amniotic fluid volume assessment in pregnancies of less than 24 weeks is not influenced by the level of operator experience or the type of ultrasonic measurement.

Amniotic Fluid↗

PubMed2000

Amniotic fluid index and single deepest pocket: weak indicators of abnormal amniotic volumes.

OBJECTIVE: To compare amniotic fluid index (AFI) with the single deepest pocket in the identification of actual abnormal amniotic fluid (AF) volumes. METHODS: One hundred seventy-nine women with singleton pregnancies at the University of Mississippi between March 1994 and June 1999 had ultrasound estimations of AF volume sequentially using the AFI and single deepest pocket techniques. Each woman subsequently had ultrasound-directed amniocentesis with dye-dilution and spectrophotometric calculation of actual AF volume. RESULTS: Actual AF volumes were low (under 5% by volume for gestational age) in 62 women, normal (5-95%) in 100 women, and high (more than 95%) in 17 women. An AFI up to 5 cm (sensitivity 10%, specificity 96%) and a single deepest pocket up to 2 cm (sensitivity 5%, specificity 98%) were similarly inadequate in identifying dye-determined low AF volumes. Likewise, AFI above 20 (sensitivity 29%, specificity 97%) and a single-deepest pocket above 8 cm (sensitivity 29%, specificity 94%) were poor in identifying dye-determined abnormally high volumes. CONCLUSION: There was no difference between AFI and single deepest pocket techniques for identifying truly abnormal AF volumes. Both techniques were unreliable for identifying true AF volumes.

Adult↗

PubMed2000

Determination of amniotic fluid volume in twin pregnancies: ultrasonographic evaluation versus operator estimation.

OBJECTIVE: We sought to determine the accuracy of amniotic fluid volume estimation (visually) in diamniotic twin pregnancy versus ultrasonography techniques. STUDY DESIGN: In this prospective study the volume of each sac in 23 sets of diamniotic twin pregnancies was subjectively and objectively estimated by a second-year obstetric resident, nurse sonographer, maternal-fetal medicine fellow, and maternal-fetal medicine staff. The actual volume was confirmed by amniocentesis and a dye-dilution technique. RESULTS: There was no difference in the total number of correct estimates of volume by level of operator experience (P =.98), ultrasonography technique (P =.87), or combined subjective versus objective correct estimates (P =.87). Identification of low volume was not different among the four evaluators (P =.48), but the percentage of correct estimates was poor (7%-29%). The 2-diameter pocket was a better predictor of oligohydramnios (57%) than the amniotic fluid index or the largest vertical pocket (12.5%; P =.002). CONCLUSION: The extremes of volume (low or high) are poorly identified by the subjective or objective assessment of volume.

Adult↗

PubMed2000

Sonographic measurements of fetal parts to predict pulmonary maturity among twins and singletons.

To determine if sonographic examination of fetus can be readily utilized to predict a mature lecithin/sphingomyelin (L/S) ratio among twins and singletons. Twins (n = 36) undergoing amniocentesis for assessment of pulmonary maturity were matched with singleton (1:2) for maternal demographics, gestational age (GA), and indications for procedure. At the time of amniocentesis, twins and singletons with mature L/S ratios differed significantly in mean GA (33.2 +/- 2.7 vs 34.5 +/- 4.6 wks, p = 0.01), biparietal diameter (BPD), abdominal circumference (AC), femur length (FL) and estimate of birth weight (EFW). Based on ten receiver operating characteristics curves constructed, the following diagnostic thresholds predicted a mature L/S ratio with a true positive rate of 100% among twins and singletons, respectively: 1) BPD $84 and $92 mm; 2) head circumference $315 and $320 mm; 3) AC $295 and $350 mm; or 4) FL $64 and $72 mm; or 5) EFW $2400 and $3200 g. Using any one of these five criteria correctly identified pulmonary maturity among 59% of twins and 28% of singletons (p = 0.001). Sonographic measurement of fetal parts or EFW may be a noninvasive method to predict a mature L/S ration among twins as well as singletons.

Adult↗

PubMed1999

Antenatal testing among 1001 patients at high risk: the role of ultrasonographic estimate of amniotic fluid volume.

OBJECTIVE: Our goal was to compare the accuracy of the amniotic fluid index and the 2-diameter pocket technique with respect to accuracy in predicting an adverse pregnancy outcome among patients at high risk undergoing antenatal testing. STUDY DESIGN: All women with high-risk pregnancies and intact membranes who underwent antenatal testing during an 18-month period were prospectively enrolled. Ultrasonographic estimates of amniotic fluid volume were performed by means of the amniotic fluid index and the 2-diameter pocket technique. Relative risks with 95% confidence intervals and receiver operator characteristic curves were calculated for patients with an ultrasonographic estimate of oligohydramnios (amniotic fluid index of </=5 cm or 2-diameter pocket of </=15 cm2) versus normal fluid level (amniotic fluid index of >5 cm or 2-diameter pocket of >15 cm2). Outcome variables studied were intrapartum and neonatal complications. RESULTS: Among 1001 patients the mean (+/-SD) amniotic fluid index was 10.5 +/- 5 cm and the mean (+/-SD) 2-diameter pocket was 18.7 +/- 13.6 cm2. Significantly more patients (46%) were considered to have oligohydramnios according to the 2-diameter pocket criteria than according to the amniotic fluid index (21%, P <.0001, relative risk 1.7, 95% confidence interval 1.5-1.8). No significant differences in the incidences of nonreactive nonstress test results, meconium-stained amniotic fluid, cesarean delivery for fetal distress, low Apgar scores, or infants with cord pH of <7.10 were observed between the oligohydramnios and normal amniotic fluid groups (P >.05) when assessed by relative risk with confidence interval and by receiver operator characteristic curves. CONCLUSIONS: Current ultrasonographic measurements with the amniotic fluid index and the 2-diameter pocket technique are poor diagnostic tests to determine whether a patient is at high risk for an adverse perinatal outcome.

Adult↗

PubMed1999

Evaluation of fetal lung maturity in diamniotic twins.

OBJECTIVE: This study was undertaken to evaluate the correspondence in fetal lung development between diamniotic twins. STUDY DESIGN: Lecithin/sphingomyelin ratios were determined for amniotic fluid specimens collected from each sac in 58 diamniotic twin pregnancies. RESULTS: Overall, the lecithin/sphingomyelin ratios of twin A and twin B and those of the larger and smaller twins of each pair were closely correlated (r >/= 0.83, P <.001). When stratified by gestational age, however, the percentage disparity in lecithin/sphingomyelin ratios between members of twin pairs was significantly greater at </=32 weeks' gestation (25%) than at >32 weeks' gestation (15%, P =.027). An analysis of the lecithin/sphingomyelin ratios of twins with a large lecithin/sphingomyelin ratio disparity (>/=20%) suggested that this disparity was a result of 1 twin having a lecithin/sphingomyelin ratio that was advanced for gestational age with respect to that of the co-twin. Disparities in lecithin/sphingomyelin ratio were not significantly affected by fetal sex or by discordance in size between the twins. CONCLUSION: At relatively early stages of diamniotic twin gestation (</=32 weeks' gestation), lecithin/sphingomyelin ratios should be obtained for both amniotic sacs to ensure accurate assessment of fetal lung maturity in both twins.

Amniocentesis↗

PubMed1999

Low amniotic fluid volume is poorly identified in singleton and twin pregnancies using the 2 x 2 cm pocket technique of the biophysical profile.

BACKGROUND: This study was done to determine the accuracy of the 2 x 2 cm pocket identifying low amniotic fluid (AF) volume in singleton and twin pregnancies. METHODS: The AF volume was evaluated by ultrasonography for the presence of a 2 x 2 cm pocket before amniocentesis. The actual AF volume was then determined by a diazo-dye reaction with subsequent spectrophotometric analysis using paraminohippurate. RESULTS: The AF volume was low in 21 of the 79 singleton pregnancies and normal in 47; hydramnios was present in 11. Among amniotic sacs of the 60 twin pairs, oligohydramnios was found in 33 amniotic sacs. normal AF volume in 80 sacs, and high volume in 7. An AF pocket smaller than 2 x 2 cm was identified in only 3 of the 79 singleton pregnancies and in only 2 of the 120 twin amniotic sacs. CONCLUSIONS: Judging AF volume on the basis of a 2 x 2 cm pocket misses more than 90% of cases of oligohydramnios in singletons and twins.

Adolescent↗

PubMed1999

First-trimester human chorionic villi express both immunoregulatory and inflammatory cytokines: a role for interleukin-10 in regulating the cytokine network of pregnancy.

PROBLEM: T-helper 2 (TH2)-type cytokines [i.e., interleukin (IL)-6, IL-10, and IL-13] and transforming growth factor (TGF)-beta are expressed by the murine decidua and/or placenta and are likely to suppress inflammatory cytokine [i.e., IL-2, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-1 alpha, and IL-1 beta] production at the maternal-fetal interface. In addition, class I IFNs may protect the fetus from immunologic rejection and viral infections. This study examines the expression of inflammatory/immunoregulatory cytokines and IL-10 production by first-trimester chorionic villi. METHOD OF STUDY: Gestational tissues (n = 5) were obtained following elective terminations performed between 7 and 9 weeks of gestation. Chorionic villous tissues were separated from fetal membranes and decidua, and total RNA was extracted. Cytokine expression was assessed by a reverse transcriptase-polymerase chain reaction technique. Chorionic villi (n = 9; 6-12 weeks gestation) were maintained in organ culture, and human chorionic gonadotropin (hCG) and IL-10 levels were determined by immunoradiometric and enzyme-linked immunosorbent assays, respectively. RESULTS: IFN-gamma and IL-2 were generally not expressed by first-trimester chorionic villi. Low to moderate levels of expression were noted for IL-1 alpha, IL-1 beta, and TNF-alpha. High levels of mRNA were noted for IFN-alpha and IFN-beta, but IFN-tau was not expressed. In all tissues, TGF-beta 1 and IL-13 were either weakly expressed or not expressed. In contrast, moderate to high levels of IL-6 and IL-10 mRNA were detected in each chorionic villous sample. In chorionic villous explants obtained at 6-11 weeks gestation production of hCG and IL-10 was greatest during the first 24 hr ([hCG] = 6961 +/- 815 mIU/mL, [IL-10] = 92 +/- 11 pg/mL) and then declined through 72 hr. CONCLUSIONS: TH1-type cytokines (IL-2, IFN-gamma) are not expressed by first-trimester chorionic villous tissues: This is possibly due to local production of IL-10. In contrast, macrophage-associated cytokines (IL-1 beta and TNF-alpha) are expressed and their regulation may be critical for fetal survival. Finally, class 1 IFNs expressed by early chorionic tissues may protect the fetus from maternal rejection and viral transmission.

Abortion, Induced↗

PubMed1998

Can we decrease postdatism in women with an unfavorable cervix and a negative fetal fibronectin test result at term by serial membrane sweeping?

OBJECTIVE: Our purpose was to determine whether the risk for postdatism can be reduced by serial membrane sweeping in women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result. STUDY DESIGN: Women with uncomplicated pregnancies, who were candidates for a vaginal delivery with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result were asked to participate in this investigation. Patients were chosen at random and assigned to a group for membrane sweeping every 3 days or to a control group who received gentle examinations every 3 days. RESULTS: Sixty-five women were selected at random for serial membrane sweeping (n = 33) or for the control group (n = 32). Although gestational age and Bishop score at study entry were similar, the gestational age on admission for delivery was earlier in the membrane sweeping group (39.9 +/- 0.3) versus the control group (41.5 +/- 0.6, P < .0001). The Bishop score on admission to labor and delivery was greater (8.8 +/- 2.1) in the membrane sweeping group than in the control group (6.2 +/- 2.7, P < .0001). The number of women admitted for labor inductions at 42 weeks' gestation was 18 of 32 (56%) in the control group versus none (0 of 24) in the membrane-sweeping group (P < .0001). CONCLUSIONS: Women with an unfavorable cervix at 39 weeks' gestation and a negative fetal fibronectin test result are at risk for not being delivered by 41 completed weeks and thus may require postdates induction or antenatal testing. Serial membrane sweeping significantly reduces the risk of postdatism and induction of labor.

Cervical Ripening↗

PubMed1998

Effect of amniotic fluid volume on neonatal outcome in diamniotic twin pregnancies.

PROBLEM: We assessed neonatal outcome of normal diamniotic twin pregnancies with known amniotic fluid (AF) volume. METHOD: The AF volume was empirically determined in 39 diamniotic twin gestations. The neonates were stratified by AF volume and evaluated for clinical outcome, gestational age, lecithin-sphingomyelin (L/S) ratio, and birth weight. RESULTS: Neonatal complications did not significantly differ among infants delivered from pregnancies with low (155 to 404 mL), moderate (405 to 807 mL), or high (808 to 5,430 mL) volumes of AF. Relatively constant volumes of AF were maintained throughout the 27 to 38 week range of gestational age, with no apparent correlation between AF volume and gestational age. Variations in the L/S ratio and newborn birth weights were also independent of AF volume. Gestational age was the only significant determinant of the frequency of neonatal complications. CONCLUSION: Amniotic fluid volume does not greatly affect neonatal outcome in normal diamniotic twin pregnancies.

Adult↗

PubMed1998

Do multiple measurements employing different ultrasonic techniques improve the accuracy of amniotic fluid volume assessment?

This investigation was undertaken to determine if the accuracy of the ultrasound assessment of abnormal amniotic fluid volume (oligohydramnios or polyhydramnios) is improved by employing multiple sonographic amniotic fluid measurements. Four ultrasound techniques consisting of the subjective assessment (ultrasonic visualization without measurement), largest vertical pocket, amniotic fluid index and 2-diameter pocket technique were performed followed by amniocentesis and dye-dilution confirmation of amniotic fluid volume in 66 singleton pregnancies. The ultrasound accuracy to detect abnormal amniotic fluid volume ranged from 61% with the largest vertical pocket to 70% with the 2-diameter pocket procedure used separately. Receiver operator characteristic curves demonstrated that combining the 4 ultrasonic measurements did not improve the accuracy of identifying amniotic fluid volumes.

Adolescent↗

PubMed1997

The accuracy of ultrasound evaluation of amniotic fluid volume in singleton pregnancies: the effect of operator experience and ultrasound interpretative technique.

The objective of this study was to evaluate the effect of operator experience and ultrasound interpretation technique on the accuracy of ultrasound estimates of amniotic fluid volume. Ultrasound evaluation was carried out by an obstetric resident, a nurse sonographer, a maternal-fetal medicine fellow, and a maternal-fetal medicine staff member to subjectively estimate (visual interpretation without sonographic measurements) amniotic fluid volume in 63 pregnancies. Amniotic fluid volume was also evaluated using ultrasound measurements based on the largest vertical pocket technique, the amniotic fluid index, and the two-diameter pocket method. The accuracy of these ultrasound estimates was assessed by comparing the ultrasound results to actual amniotic fluid volume as determined by a dye-dilution technique. For analysis, amniotic fluid volumes were classified as oligohydramnios, normal, or hydramnios using established volumetric criteria for singleton pregnancies. Subjective estimates ranged from 65% to 70% correct and did not differ by operator experience except for the more accurate diagnosis of hydramnios by the maternal-fetal medicine staff. The three sonographic measurements were similar in overall accuracy (59-67%). The two-diameter pocket method was, however, significantly more accurate in identifying oligohydramnios. It appears that neither operator experience nor sonographic technique greatly affects the accuracy of ultrasound estimates of amniotic fluid volume.

Adolescent↗

PubMed1997

The accuracy of the summated amniotic fluid index in evaluating amniotic fluid volume in twin pregnancies.

OBJECTIVE: Our purpose was to determine the accuracy of the summated amniotic fluid index designed to estimate the total amniotic fluid volume in twin pregnancies. STUDY DESIGN: The summated amniotic fluid index was measured in 62 normal diamniotic twin pregnancies by adding the deepest vertical pockets in the four quadrants. Actual amniotic fluid volume was then determined in all 124 amniotic sacs by amniocentesis and a dye-dilution technique. For data analysis, amniotic fluid volumes were classified by percentile with use of previously reported norms. RESULTS: There were significant differences in the percentile distribution of amniotic fluid volume as estimated by the summated amniotic fluid index and the actual volume as determined by dye dilution (p < 0.001). The summated amniotic fluid index has a sensitivity of only 13% in predicting amniotic sac volume. CONCLUSION: The summated amniotic fluid index is a poor predictor of intertwin differences in amniotic fluid volume and cannot identify twin pairs at risk for oligohydramnios and hydramnios.

Adult↗

PubMed1997

Ultrasonographic assessment of amniotic fluid does not reflect actual amniotic fluid volume.

OBJECTIVE: Our objective was to compare the ability of two methods of amniotic fluid assessment (two-diameter amniotic fluid pocket versus the amniotic fluid index) to predict oligohydramnios (actual amniotic fluid volume < 500 ml) or polyhydramnios (actual amniotic fluid volume > 1500 ml). STUDY DESIGN: The amniotic fluid index and the two-diameter amniotic fluid pocket were assessed before amniocentesis and determination of amniotic fluid volume with the dye (aminohippurate sodium)-dilution technique. To assess the detection of either oligohydramnios or polyhydramnios, the areas under the receiver-operator characteristic curves (+/-SE) were estimated by the point-to-point trapezoidal method of integration. Prediction limits were calculated by regression analysis of amniotic fluid index or two-diameter amniotic fluid pocket versus actual amniotic fluid volume and determination of 95th percentile ranges for amniotic fluid volume. RESULTS: We studied 144 patients with a mean (+/-SD) gestational age of 31.7 +/- 5.5 weeks; mean (+/-SD) amniotic fluid index and two-diameter amniotic fluid pocket were 12.6 +/- 6.1 cm and 21.2 +/- 18.4 cm2, respectively. Mean (+/-SD) actual amniotic fluid volume was 722 +/- 735 ml (range 101 to 4318 ml). The areas under the four receiver-operator characteristic curves were not significantly different from the nondiagnostic line (p < 0.05). Regression slopes (r values) for amniotic fluid index and two-diameter amniotic fluid pocket versus actual amniotic fluid volume were 0.34 and 0.23, respectively. Calculation of the prediction limit for 95% confidence that oligohydramnios is absent requires that the amniotic fluid index be 30 cm and the two-dimension amniotic fluid pocket be 90 cm2, both thresholds of which are currently considered to represent clinical polyhdramnios. CONCLUSIONS: Both amniotic fluid index and two-dimension amniotic fluid pocket appear to be inaccurate predictors of actual oligohydramnios or polyhydramnios when compared with dye-dilution calculations of actual amniotic fluid volume.

Adult↗

PubMed1997

Amniotic fluid volume in normal singleton pregnancies.

OBJECTIVE: To evaluate the amniotic fluid (AF) volume in normal singleton pregnancies from 15 to 40 weeks. METHODS: This prospective study evaluated the AF volume in singleton pregnancies undergoing amniocentesis for genetic assessment of fetal karyotype, preterm labor, or fetal lung maturity. Amniotic fluid volume was determined using a dye dilution technique. To assess the relationship between AF volume and estimated gestational age, a nonlinear regression model was applied. RESULTS: One hundred forty-four normal singleton pregnancies had AF volume evaluated. There was wide variability in the measured AF volumes with a significant (P < .01) increase in AF volume as a function of gestational age. Growth curve modeling estimated that AF volume continued to increase until 40 weeks' gestation. Analyses of the observed AF volume indicated that AF volume nearly doubled after 30 weeks' gestation. CONCLUSION: In contrast to other reports indicating that maximal AF volume in singleton gestations is expected early in the third trimester, we observed the attainment of maximal AF volume near term.

Adult↗