Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2020;42(9):529-534
The purpose of the present study was to analyze the influence of chorionicity in the biometric parameters crown-rump length (CRL), birthweight (BW), crown-rump length discordancy (CRLD) and birthweight discordancy (BWD), determine the correlation between these latter two in cases of intertwin discordancy, and to analyze the influence of chronicity in the presence of these discordancies with clinical relevance (> 10% and > 15%, respectively).
The present study was a retrospective study based on the twin pregnancy database of the Centro Hospitalar S. João (2010-2015), including 486 fetuses among 66 monochorionic (MC) and 177 dichorionic gestations (DC). The inclusion criteria were multiple pregnancies with 2 fetuses and healthy twin gestations. The exclusion criteria were trichorionic gestations and pregnancies with inconclusive chorionicity, multiple pregnancy with ≥ 3 fetuses and pathological twin gestations.
No statistically significant difference was found in BW (p = 0.09) and in its discordancy (p = 0.06) nor in CRL (p = 0.48) and its discordancy (p = 0.74) between MCs and DCs. Crown-rump length discordancy and birthweight discordancy were correlated by the regression line “BWD = 0.8864 x CRLD + 0.0743,” with r2 = 0.1599. Crown-rump length discordancy > 10% was found in 7.58% of monochorionic and in 13.56% of dichorionic twins. Birthweight discordancy > 15% was detected in 16.67% of monochorionic and in 31.64% of dichorionic twins.
No statistically significant influence of chorionicity was identified in both birthweight and birthweight discordancy, as in crown-rump length and crown-rump length discordancy. Birthweight discordancy was correlated to crown-rump length discordancy in 20% of cases.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 1999;21(10):569-576
DOI 10.1590/S0100-72031999001000002
Purpose: to estimate growth curves and tables of average biparietal diameter and average head circumference of twin gestations and to compare them with published growth curves for singletons and twins. Methods: growth curves and tables of average biparietal diameter and average head circumference were obtained from sonographic examinations of 34 patients with twin gestations without maternal and fetal complications. Sonographic examinations were performed each 2 or 3 weeks by a single observer. The parameters were compared with existing growth curves for singletons and twins. Results: curves and tables of biparietal diameter and head circumference in relation to gestational age were obtained. The study revealed difference in growth pattern mainly regarding the 3rd trimester in relation to singletons (Hadlock et al.15). The difference between the average values were 6 mm (biparietal diameter) and 2.0 cm (head circumference) at the 39th week of gestation. Also, some differences were observed relative to the twin studies. Conclusion: this study revealed that growth curves for average biparietal diameter and average head circumference of singletons are not appropriate to determine gestational age in twin gestations of the studiced population principally at the 3rd trimester
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2000;22(5):281-286
DOI 10.1590/S0100-72032000000500005
Purpose: to evaluate the effectiveness of the transverse cerebellar diameter (TCD), by ultrasonography, in the evolution of the fetal growth, and to relate it to gestational age, biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Method: a prospective and longitudinal study was performed on 254 pregnant women considered of low risk, with a gestational age from 20 to 40 weeks. Only 55 pregnant women were included in the study, according to inclusion and exclusion criteria. All the examinations, 217 ultrasonographic evaluations, were done by the author (LN), at least three and at most six examinations for each pregnant woman being accomplished at an interval of one to five weeks. Normality patterns were established between the 10 and 90 percentiles for each gestational age and confirmed postnatally. Results: the transverse cerebellar diameter presented a good correlation with the gestational age either as a dependent variable (R² = 0.90) or as an independent variable (R² = 0.92). A significant relationship was found in the evaluation of the fetal growth between the TCD and the several fetal parameters: BPD and HC (R² = 0.92), FL (R² = 0.90) and AC (R² = 0.89). Conclusions: the transverse cerebellar diameter is a parameter that should be used in the follow-up of development and of fetal growth because of the ascending pattern of its growth curve. Any up- or downward alteration in the growth curve can be useful for the detection of deviations of fetal growth.
Summary
Revista Brasileira de Ginecologia e Obstetrícia. 2001;23(4):247-251
DOI 10.1590/S0100-72032001000400008
Purpose: to determine the feasibility of early ultrasonographic identification of fetal gender. Methods: a prospective study in a University Department of Obstetrics and Gynecology. A total of 592 women underwent ultrasonography at 11-14 weeks of gestation. Fetal gender was identified according to genital tubercle position (vertical or horizontal) at sagittal plane and confirmed at birth or by karyotype analysis. Results: the overall accuracy of correctly assigning fetal gender was 84%. The success of identification increased with gestational age, being 72%, 85% and 89% at 11, 12 and 13 weeks, respectively. The accuracy of correctly identifying fetal sex significantly changed with operator training, being 83.5% at the beginning and 93.6% at the end of the study. Conclusion: ultrasound determination of fetal gender is feasible, with good accuracy and may be of potential use to avoid invasive testing in family histories of X-linked disorders.