Você pesquisou por y - Revista Brasileira de Ginecologia e Obstetrícia
You searched for:"Patrícia Spara"
We found (13) results for your search.Summary
Rev Bras Ginecol Obstet. 1999;21(3):141-146
DOI 10.1590/S0100-72031999000300004
Purpose: to study fetal oxygen saturation (SpO2) levels during labor by continuous pulse oximetry tecnique, and its relation to umbilical artery (UA) pH. Patients and Methods: fetal SpO2 levels were measured during labor by the pulse oximetry technique in 50 subjects. Average values of SpO2 were compared between the first and second stage of labor, with the first stage further subdivided into phases, according to cervical dilatation of (<=4 cm, 5-7 cm and 8-9 cm). SpO2 values were studied in relation to umbilical artery pH at birth ( > or = 7.20 and <7.20). SpO2 > or = 30.0% was considered normal. Results: fetal SpO2 averages during the first stage were 53.0 ± 7.3% and 44.2 ± 6.8% (UA pH > or = 7.20 and <7.20, respectively; p<0.01). When the first stage was subdivided, the fetal SpO2 averages (UA pH > or = 7.20) were 55.1 ± 5.1% (<=4 cm), 52.3 ± 4.6% (5-7 cm) and 51.5 ± 7.2% (8-9 cm); for UA pH <7.20, the fetal SpO2 averages were 46.3 ± 5.1% (<=4 cm), 43.6 ± 6.7% (5-7 cm) and 42.8 ± 5.8% (8-9 cm). Considering the UA pH, these differences were statistically significant (p<0.01). Conclusion: a significant decrease of oxygen saturation values was observed during labor when fetal pulse oximetry was used.
Summary
Rev Bras Ginecol Obstet. 1999;21(3):141-146
DOI 10.1590/S0100-72031999000300004
Purpose: to study fetal oxygen saturation (SpO2) levels during labor by continuous pulse oximetry tecnique, and its relation to umbilical artery (UA) pH. Patients and Methods: fetal SpO2 levels were measured during labor by the pulse oximetry technique in 50 subjects. Average values of SpO2 were compared between the first and second stage of labor, with the first stage further subdivided into phases, according to cervical dilatation of (<=4 cm, 5-7 cm and 8-9 cm). SpO2 values were studied in relation to umbilical artery pH at birth ( > or = 7.20 and <7.20). SpO2 > or = 30.0% was considered normal. Results: fetal SpO2 averages during the first stage were 53.0 ± 7.3% and 44.2 ± 6.8% (UA pH > or = 7.20 and <7.20, respectively; p<0.01). When the first stage was subdivided, the fetal SpO2 averages (UA pH > or = 7.20) were 55.1 ± 5.1% (<=4 cm), 52.3 ± 4.6% (5-7 cm) and 51.5 ± 7.2% (8-9 cm); for UA pH <7.20, the fetal SpO2 averages were 46.3 ± 5.1% (<=4 cm), 43.6 ± 6.7% (5-7 cm) and 42.8 ± 5.8% (8-9 cm). Considering the UA pH, these differences were statistically significant (p<0.01). Conclusion: a significant decrease of oxygen saturation values was observed during labor when fetal pulse oximetry was used.
Summary
Rev Bras Ginecol Obstet. 2004;26(2):147-151
DOI 10.1590/S0100-72032004000200010
PURPOSE: to assess the length of the uterine cervix by transvaginal ultrasonography in pregnant women with preterm premature rupture of membranes. METHODS: the study group (Ge) consisted of 26 pregnant women with gestational age between 24 and 36 weeks and the control group (Gc) of 49 clinically normal patients at the same gestational age. The patients were evaluated between the 24th to 28th, 28th to 32th and 32th to 36th weeks. The groups were divided into subgroups Ge24-28, Ge28-32, Ge32-36 and Gc24-28, Gc28-32, Gc32-36, according to the study or control group. The cervix length was measured by transvaginal ultrasonography as the linear distance between the internal and external cervical os. RESULTS: we observed significant differences in cervix length between Ge24-28 and Gc24-28 groups whose values were, respectively, 24.3 and 33.0 mm (p=0.04), and between Ge32-36 and Gc32-36, 20.1 and 28.0 mm, respectively (p=0.005). The latency periods of Ge24-28, Ge28-32 and Ge32-36 were, respectively, seven, five and three days, showing a positive correlation with cervix length (r=0.66) and a negative correlation with gestational age (r=-0.27). CONCLUSIONS: the length of the uterine cervix varied with the gestational age when premature preterm rupture of the membranes was detected, with the length being shorter in the study group than in the control group betweeen the 24th and 28th and 32th and 36th weeks. In addition, it was demonstrated that, the shorter the cervix length, the shorter the latency time, with a reduction in the latency period with increasing gestational age at the time of rupture.
Summary
Rev Bras Ginecol Obstet. 2004;26(2):147-151
DOI 10.1590/S0100-72032004000200010
PURPOSE: to assess the length of the uterine cervix by transvaginal ultrasonography in pregnant women with preterm premature rupture of membranes. METHODS: the study group (Ge) consisted of 26 pregnant women with gestational age between 24 and 36 weeks and the control group (Gc) of 49 clinically normal patients at the same gestational age. The patients were evaluated between the 24th to 28th, 28th to 32th and 32th to 36th weeks. The groups were divided into subgroups Ge24-28, Ge28-32, Ge32-36 and Gc24-28, Gc28-32, Gc32-36, according to the study or control group. The cervix length was measured by transvaginal ultrasonography as the linear distance between the internal and external cervical os. RESULTS: we observed significant differences in cervix length between Ge24-28 and Gc24-28 groups whose values were, respectively, 24.3 and 33.0 mm (p=0.04), and between Ge32-36 and Gc32-36, 20.1 and 28.0 mm, respectively (p=0.005). The latency periods of Ge24-28, Ge28-32 and Ge32-36 were, respectively, seven, five and three days, showing a positive correlation with cervix length (r=0.66) and a negative correlation with gestational age (r=-0.27). CONCLUSIONS: the length of the uterine cervix varied with the gestational age when premature preterm rupture of the membranes was detected, with the length being shorter in the study group than in the control group betweeen the 24th and 28th and 32th and 36th weeks. In addition, it was demonstrated that, the shorter the cervix length, the shorter the latency time, with a reduction in the latency period with increasing gestational age at the time of rupture.
Summary
Rev Bras Ginecol Obstet. 1998;20(1):25-32
DOI 10.1590/S0100-72031998000100005
It is universally accepted that prenatal care has a beneficial impact on perinatal outcome. However, it is unclear whether access to early and frequent prenatal care influences the impact of pregnancy complications on birth weight. The objective of the present study was to determine the effectiveness of prenatal care, concerning antenatal visits (number and time of the first one), on gestational age and fetal weight at birth. We assessed prospectively the effect of the antenatal care in a group of 648 infants born consecutively at the University Hospital of Santa Maria, weighing from <1000 to >4000 g, and from <28 to >40 weeks of gestational age. Preterm delivery (<37 weeks) accounted for 17.7% of all deliveries, low birth-weight infants (<2500 g) for 20.5%, and very low birth-weight infants (<1000 g) for 2.8%. When the first antenatal visit was performed before the 12th week, only 5.1% of the babies were born with <37 weeks of gestational age or weight at birth of <2500 g. However, when the first visit was after the 28th week, the percentage of preterm delivery was 41.3% and of birth weight <2500 g was 43.5%. A significant association between higher frequency of antenatal visits, early care and decrease in preterm delivery frequency and low birth-weight infants was noted (p <0.001). We conclude that increase in the number of antenatal visits and early care can reduce the preterm delivery and low-birth weight infant rates.
Summary
Rev Bras Ginecol Obstet. 1998;20(1):25-32
DOI 10.1590/S0100-72031998000100005
It is universally accepted that prenatal care has a beneficial impact on perinatal outcome. However, it is unclear whether access to early and frequent prenatal care influences the impact of pregnancy complications on birth weight. The objective of the present study was to determine the effectiveness of prenatal care, concerning antenatal visits (number and time of the first one), on gestational age and fetal weight at birth. We assessed prospectively the effect of the antenatal care in a group of 648 infants born consecutively at the University Hospital of Santa Maria, weighing from <1000 to >4000 g, and from <28 to >40 weeks of gestational age. Preterm delivery (<37 weeks) accounted for 17.7% of all deliveries, low birth-weight infants (<2500 g) for 20.5%, and very low birth-weight infants (<1000 g) for 2.8%. When the first antenatal visit was performed before the 12th week, only 5.1% of the babies were born with <37 weeks of gestational age or weight at birth of <2500 g. However, when the first visit was after the 28th week, the percentage of preterm delivery was 41.3% and of birth weight <2500 g was 43.5%. A significant association between higher frequency of antenatal visits, early care and decrease in preterm delivery frequency and low birth-weight infants was noted (p <0.001). We conclude that increase in the number of antenatal visits and early care can reduce the preterm delivery and low-birth weight infant rates.
Summary
Rev Bras Ginecol Obstet. 1999;21(6):335-339
DOI 10.1590/S0100-72031999000600006
Purpose: to study the sensitivity and specificity based on fetal oxygen saturation (SpO2) values and fetal heart rate (FHR) patterns during labor, for the prognosis of acidotic fetuses at birth. Patients and Methods: SpO2 values were obtained by fetal pulse oximetry technique. A fetal SpO2 value > or = 30% was considered normal, and an SpO2 which remained <30.0% for more than 10 min between contractions was considered abnormal. Fetal SpO2 and FHR tracings were obtained during the first and second stage of labor. FHR classification used in the study has been derived from the National Institute of Child Health and Human Development19. Results: a total of 72 subjects were studied. The sensitivity and specificity, based on SpO2, were 61.5% and 96.6%, respectively, whereas the sensitivity and specificity based on FHR patterns were 69.2% and 66.1%. Positive and negative predictive values based on SpO2 were 80% and 91.9%, respectively, and based on FHR patterns were 31% and 90.7%, respectively. Conclusions: a good fetal SpO2 specificity for prognosis of acidotic fetuses at birth was found, if compared with FHR pattern specificity, whereas sensitivity was poor for both methods. However, the number of acidotic fetuses was too small to allow more conclusions
Summary
Rev Bras Ginecol Obstet. 1999;21(6):335-339
DOI 10.1590/S0100-72031999000600006
Purpose: to study the sensitivity and specificity based on fetal oxygen saturation (SpO2) values and fetal heart rate (FHR) patterns during labor, for the prognosis of acidotic fetuses at birth. Patients and Methods: SpO2 values were obtained by fetal pulse oximetry technique. A fetal SpO2 value > or = 30% was considered normal, and an SpO2 which remained <30.0% for more than 10 min between contractions was considered abnormal. Fetal SpO2 and FHR tracings were obtained during the first and second stage of labor. FHR classification used in the study has been derived from the National Institute of Child Health and Human Development19. Results: a total of 72 subjects were studied. The sensitivity and specificity, based on SpO2, were 61.5% and 96.6%, respectively, whereas the sensitivity and specificity based on FHR patterns were 69.2% and 66.1%. Positive and negative predictive values based on SpO2 were 80% and 91.9%, respectively, and based on FHR patterns were 31% and 90.7%, respectively. Conclusions: a good fetal SpO2 specificity for prognosis of acidotic fetuses at birth was found, if compared with FHR pattern specificity, whereas sensitivity was poor for both methods. However, the number of acidotic fetuses was too small to allow more conclusions
Summary
Rev Bras Ginecol Obstet. 2005;27(1):37-43
DOI 10.1590/S0100-72032005000100008
PURPOSE: to investigate the normal peak expiratory flow values in healthy pregnant women employing a portable expiratory apparatus (Mini-Wright Peak Flow Meter), and to relate the obtained measurements to each patient's height, body mass index (BMI) and age, along gestation. METHODS: a longitudinal prospective study including 26 pregnant women followed up from the first trimester to the 36th week of gestation and examined every four weeks. On the occasion of seven visits, the pregnant women performed forced exhaling into a portable expiratory apparatus three times, with the highest value being considered the peak expiratory flow. All measurements were made under the same investigator's supervision in order to reduce the margin of error. Pearson coefficient was used to calculate the correlation between flow and BMI, between flow and patient's height, and between flow and patient's age. RESULTS: the variation in flow values during pregnancy can be determined by flow = 328.32 -0.07 x week, with a Pearson coefficient equal to zero. To determine whether there was a difference in the correlation coefficients between BMI and flow, we compared the lowest coefficient (0.47 for week 30, flow = 123.49 + 7.64 x BMI) with the highest coefficient (0.59 for week 34, flow = 87.77 + 9.05 x BMI) of each studied time interval and obtained a value of 0.22, indicating a good correlation between the flow and BMI variables. There was a positive correlation between height and flow (Pearson = 0.61), with flow = -477.47 + 497.38 x height. The correlation coefficient between flow and age was 0.24, with the equation obtained in this case being non-linear. CONCLUSIONS: peak expiratory flow values did not change along gestation. Higher flows were observed in taller women. Pregnant women with a higher BMI before gestation presented higher flows. There was no correlation between flow and maternal age.
Summary
Rev Bras Ginecol Obstet. 2005;27(1):37-43
DOI 10.1590/S0100-72032005000100008
PURPOSE: to investigate the normal peak expiratory flow values in healthy pregnant women employing a portable expiratory apparatus (Mini-Wright Peak Flow Meter), and to relate the obtained measurements to each patient's height, body mass index (BMI) and age, along gestation. METHODS: a longitudinal prospective study including 26 pregnant women followed up from the first trimester to the 36th week of gestation and examined every four weeks. On the occasion of seven visits, the pregnant women performed forced exhaling into a portable expiratory apparatus three times, with the highest value being considered the peak expiratory flow. All measurements were made under the same investigator's supervision in order to reduce the margin of error. Pearson coefficient was used to calculate the correlation between flow and BMI, between flow and patient's height, and between flow and patient's age. RESULTS: the variation in flow values during pregnancy can be determined by flow = 328.32 -0.07 x week, with a Pearson coefficient equal to zero. To determine whether there was a difference in the correlation coefficients between BMI and flow, we compared the lowest coefficient (0.47 for week 30, flow = 123.49 + 7.64 x BMI) with the highest coefficient (0.59 for week 34, flow = 87.77 + 9.05 x BMI) of each studied time interval and obtained a value of 0.22, indicating a good correlation between the flow and BMI variables. There was a positive correlation between height and flow (Pearson = 0.61), with flow = -477.47 + 497.38 x height. The correlation coefficient between flow and age was 0.24, with the equation obtained in this case being non-linear. CONCLUSIONS: peak expiratory flow values did not change along gestation. Higher flows were observed in taller women. Pregnant women with a higher BMI before gestation presented higher flows. There was no correlation between flow and maternal age.
Summary
Rev Bras Ginecol Obstet. 2006;28(1):38-43
DOI 10.1590/S0100-72032006000100007
PURPOSE: to determine the intraobserver and interobserver reproducibility of endometrial volume measurements using the VOCAL®-imaging program (Virtual Organ Computer-aided AnaLysis). METHODS: one three-dimensional (3-D) ultrasound dataset of the endometrium was obtained from each of five infertile women with different endometrial volumes. For each 3-D dataset, the endometrial volume was calculated by two different observers using the manual mode in four different rotational steps (30º, 15º, 9º and 6º). Ten measurements were obtained with each method and observer from each 3-D dataset. We have used one-way ANOVA and the Tukey post-test to verify the differences among means and the intraclass correlation coefficient to test reliability. RESULTS: rotational methods employing a rotation step of 30º were associated with lower endometrial volume readings in 3 of the 5 patients. There were no significant differences between the means obtained by the 15º, 9º or 6º step rotation. No significant difference was found between the means obtained by the two different observers. The intraclass correlation coefficients were significantly lower with 30º (all under 0.984) than with the other step rotations (all above 0.996). CONCLUSIONS: the use of a rotational step of 15º or less provides reliable readings of endometrial volume: there were no significant differences between the means calculated by the two observers, associated with highintraclass correlation coefficient (>0.996). We recommend the 15º step rotation because it is quicker to be performed than 6º and 9º.
Summary
Rev Bras Ginecol Obstet. 2006;28(1):38-43
DOI 10.1590/S0100-72032006000100007
PURPOSE: to determine the intraobserver and interobserver reproducibility of endometrial volume measurements using the VOCAL®-imaging program (Virtual Organ Computer-aided AnaLysis). METHODS: one three-dimensional (3-D) ultrasound dataset of the endometrium was obtained from each of five infertile women with different endometrial volumes. For each 3-D dataset, the endometrial volume was calculated by two different observers using the manual mode in four different rotational steps (30º, 15º, 9º and 6º). Ten measurements were obtained with each method and observer from each 3-D dataset. We have used one-way ANOVA and the Tukey post-test to verify the differences among means and the intraclass correlation coefficient to test reliability. RESULTS: rotational methods employing a rotation step of 30º were associated with lower endometrial volume readings in 3 of the 5 patients. There were no significant differences between the means obtained by the 15º, 9º or 6º step rotation. No significant difference was found between the means obtained by the two different observers. The intraclass correlation coefficients were significantly lower with 30º (all under 0.984) than with the other step rotations (all above 0.996). CONCLUSIONS: the use of a rotational step of 15º or less provides reliable readings of endometrial volume: there were no significant differences between the means calculated by the two observers, associated with highintraclass correlation coefficient (>0.996). We recommend the 15º step rotation because it is quicker to be performed than 6º and 9º.
Summary
Rev Bras Ginecol Obstet. 2005;27(7):387-392
DOI 10.1590/S0100-72032005000700004
PURPOSE: to assess peak systolic velocity (PSV) and the resistance index (RI) in the middle cerebral artery (MCA), suprarenal aorta (SRA) and infrarenal aorta (IRA) of the fetus and in the umbilical artery (UA) between the 22nd and 38th week of gestation. METHODS: a prospective study which evaluated the parameters of 33 normal fetuses in the 22nd, 26th, 30th, and 38th week of gestation. Pregnant women with a singleton fetus with no diseases or complications and who agreed to participate were included in the study. Exclusion criteria were fetal malformations, discontinuation of prenatal care visits and mothers who smoked, used alcohol or illicit drugs. Ultrasound examinations were performed by a single observer. For the acquisition of the Doppler velocimetry tracing in the MCA, SRA, IRA and UA, the sample volume was 1 to 2 mm, placed in the center of the arteries. The insonation angle was 5º to 19º in the MCA, below 45º in the SRA and IRA, and less than 60º in the UA. We used a wall filter of 50-100 Hz. The parameters were calculated automatically with the frozen image, three measurements being made. The final result was obtained by the arithmetic mean of the three values. Data were analyzed by analysis of variance (ANOVA), post hoc Bonferroni test, Pearson's correlation, and regression analysis. The level of significance was set at p<0.05 in all analyses. RESULTS: PSV increased from 26.3 to 57.7 cm/s in the MCA between the 22nd and the 38th week of gestation (p<0.05). In the SRA and in the IRA, PSV increased between the 22nd and 34th week of gestation, from 74.6 and 59.0 cm/s to 106.0 and 86.6 cm/s, respectively (p<0.05). In the UA, PSV increased between the 22nd and the 34th week of gestation, but decreased from 55.5 to 46.2 cm/s between the 34th and the 38th week of gestation. In the MCA, the RI was lower in the 22nd (0.81) and 38th week of gestation (0.75) and higher (0.85) in the 26th week (p<0.05). In the SRA, the RI values were stable in all weeks and in the IRA they were stable in most weeks (p>0.05). In the UA, RI decreased from 0.69 to 0.56 between the 22nd and 38th week of gestation (p<0.05). CONCLUSION: in normal fetuses, in the second half of gestation PSV increased in the MCA, SRA and IRA, decreasing in the UA between the 34th and 38th week of gestation. RI was lower in the 22nd and 38th weeks of gestation in the MCA, decreased between the 22nd and the 38th week in the UA, and was constant in most of the gestational weeks in the SRA and IRA.
Summary
Rev Bras Ginecol Obstet. 2005;27(7):387-392
DOI 10.1590/S0100-72032005000700004
PURPOSE: to assess peak systolic velocity (PSV) and the resistance index (RI) in the middle cerebral artery (MCA), suprarenal aorta (SRA) and infrarenal aorta (IRA) of the fetus and in the umbilical artery (UA) between the 22nd and 38th week of gestation. METHODS: a prospective study which evaluated the parameters of 33 normal fetuses in the 22nd, 26th, 30th, and 38th week of gestation. Pregnant women with a singleton fetus with no diseases or complications and who agreed to participate were included in the study. Exclusion criteria were fetal malformations, discontinuation of prenatal care visits and mothers who smoked, used alcohol or illicit drugs. Ultrasound examinations were performed by a single observer. For the acquisition of the Doppler velocimetry tracing in the MCA, SRA, IRA and UA, the sample volume was 1 to 2 mm, placed in the center of the arteries. The insonation angle was 5º to 19º in the MCA, below 45º in the SRA and IRA, and less than 60º in the UA. We used a wall filter of 50-100 Hz. The parameters were calculated automatically with the frozen image, three measurements being made. The final result was obtained by the arithmetic mean of the three values. Data were analyzed by analysis of variance (ANOVA), post hoc Bonferroni test, Pearson's correlation, and regression analysis. The level of significance was set at p<0.05 in all analyses. RESULTS: PSV increased from 26.3 to 57.7 cm/s in the MCA between the 22nd and the 38th week of gestation (p<0.05). In the SRA and in the IRA, PSV increased between the 22nd and 34th week of gestation, from 74.6 and 59.0 cm/s to 106.0 and 86.6 cm/s, respectively (p<0.05). In the UA, PSV increased between the 22nd and the 34th week of gestation, but decreased from 55.5 to 46.2 cm/s between the 34th and the 38th week of gestation. In the MCA, the RI was lower in the 22nd (0.81) and 38th week of gestation (0.75) and higher (0.85) in the 26th week (p<0.05). In the SRA, the RI values were stable in all weeks and in the IRA they were stable in most weeks (p>0.05). In the UA, RI decreased from 0.69 to 0.56 between the 22nd and 38th week of gestation (p<0.05). CONCLUSION: in normal fetuses, in the second half of gestation PSV increased in the MCA, SRA and IRA, decreasing in the UA between the 34th and 38th week of gestation. RI was lower in the 22nd and 38th weeks of gestation in the MCA, decreased between the 22nd and the 38th week in the UA, and was constant in most of the gestational weeks in the SRA and IRA.
Summary
Rev Bras Ginecol Obstet. 2003;25(6):437-442
DOI 10.1590/S0100-72032003000600009
PURPOSE: to study the evolution of the resistance and pulsatility indices, maximum velocity, final diastolic velocity and time of acceleration of the middle cerebral artery of fetuses between 22 and 38 weeks of gestation. METHODS: a prospective and longitudinal observational study was conducted on 33 fetuses of normal pregnant women evaluated between 22 and 38 weeks of pregnancy. The gestational age was determined on the basis of the date of the last menstruation and/or by ultrasound examination during the first trimester. Doppler ultrasound examination was performed by a single observer using an Image Point 1800 (Hewlett Packard) apparatus equipped with a multiple frequency transducer. For the acquisition of the Doppler tracing of the middle cerebral artery, the sample indicator was calibrated for a sample volume of 1 mm³ and placed on the anterior middle cerebral artery as close as possible to the skullcap. The insonation angle was kept between 5º and 19º and the filter was adjusted to a frequency of 50-100 Hz. The newborn infants were evaluated in order to confirm that the fetuses were vigorous and adequate for gestational age. RESULTS: the results obtained for the resistance and pulsatility indices revealed a 2nd-degree equation, representing a parabola whose values for the resistance index were 0.81 during the 22nd week and 0.75 during the 38th week. The pulsatility index was 1.59 during the 22nd week and 1.45 during the 38th week. Maximum systolic velocity increased progressively along pregnancy, with values of 26.3 cm/s during the 22nd week and 57.7 cm/s during the 38th week. Final diastolic velocity increased progressively from the 26th week (5.21 cm/s) to term (14.6 cm/s). Acceleration time increased significantly only between 26 and 30 weeks, with values of 0.04 s during the 26th week and 0.05 s during the 30th week. CONCLUSION: it was concluded that the evolution of the resistance and pulsatility indices and of maximum systolic velocity were similar to those of most studies described in the literature. Acceleration time presented few modifications during the evaluated gestational weeks.
Summary
Rev Bras Ginecol Obstet. 2003;25(6):437-442
DOI 10.1590/S0100-72032003000600009
PURPOSE: to study the evolution of the resistance and pulsatility indices, maximum velocity, final diastolic velocity and time of acceleration of the middle cerebral artery of fetuses between 22 and 38 weeks of gestation. METHODS: a prospective and longitudinal observational study was conducted on 33 fetuses of normal pregnant women evaluated between 22 and 38 weeks of pregnancy. The gestational age was determined on the basis of the date of the last menstruation and/or by ultrasound examination during the first trimester. Doppler ultrasound examination was performed by a single observer using an Image Point 1800 (Hewlett Packard) apparatus equipped with a multiple frequency transducer. For the acquisition of the Doppler tracing of the middle cerebral artery, the sample indicator was calibrated for a sample volume of 1 mm³ and placed on the anterior middle cerebral artery as close as possible to the skullcap. The insonation angle was kept between 5º and 19º and the filter was adjusted to a frequency of 50-100 Hz. The newborn infants were evaluated in order to confirm that the fetuses were vigorous and adequate for gestational age. RESULTS: the results obtained for the resistance and pulsatility indices revealed a 2nd-degree equation, representing a parabola whose values for the resistance index were 0.81 during the 22nd week and 0.75 during the 38th week. The pulsatility index was 1.59 during the 22nd week and 1.45 during the 38th week. Maximum systolic velocity increased progressively along pregnancy, with values of 26.3 cm/s during the 22nd week and 57.7 cm/s during the 38th week. Final diastolic velocity increased progressively from the 26th week (5.21 cm/s) to term (14.6 cm/s). Acceleration time increased significantly only between 26 and 30 weeks, with values of 0.04 s during the 26th week and 0.05 s during the 30th week. CONCLUSION: it was concluded that the evolution of the resistance and pulsatility indices and of maximum systolic velocity were similar to those of most studies described in the literature. Acceleration time presented few modifications during the evaluated gestational weeks.
