Fetal Doppler changes 1 week after endoscopic equatorial laser for twin-to-twin transfusion syndrome: A longitudinal study.

OBJECTIVE: To investigate sequential Doppler changes in donors and recipients before and 1 week after endoscopic laser for twin-to-twin transfusion syndrome (TTTS) and to examine factors that may be associated with such changes. METHODS: In TTTS pregnancies undergoing laser treatment, we examined fetal Doppler changes before and 1 week postintervention. Intrauterine death rates and preoperative factors were analyzed in relation to Doppler changes. RESULTS: Among 129 (85.4%) donors surviving at 1 week after laser, there was normalization of umbilical artery flow in 26 (72.2%) of 36 cases with preoperative abnormal Dopplers. In the remaining 10 (27.8%) fetuses, abnormal findings persisted. The rate of later intrauterine death was significantly higher in the latter group (6 of 10, 60.0%) compared with fetuses in which Doppler findings normalized (4 of 26, 15.4%; P < .05), with no difference in the rate of severe donor growth restriction between the 2 groups (80.0% vs 65.4%, respectively; P = .688). CONCLUSIONS: In about 70% of TTTS donors with preoperative abnormal umbilical artery Doppler, there was normalization 1 week after endoscopic laser. The incidence of fetal growth restriction was not significantly different in donors with persistence of Doppler abnormalities compared with those with normalized findings.

Correlation between Subpubic Arch Angle and Mode of Delivery in Large-for-Gestational-Age Fetuses.

OBJECTIVES: A narrow subpubic arch angle (SPA) has been associated with a higher risk of operative delivery and prolonged labor. The aim of this study was to evaluate the correlation between SPA and labor outcome in a cohort of women delivering a large-for-gestational-age (LGA) fetus. METHODS: An observational study involving two Italian tertiary centers (Parma and Rome) was carried out. Nulliparous women referred to the antepartum clinic between 35 and 39 weeks due to an increased risk of having an LGA fetus at birth were prospectively selected for the study purpose. Within the study cohort, SPA measurements were obtained by means of transperineal 3D ultrasound. Elective caesarean section and birth weight below 3,750 g represented exclusion criteria. In the final study group, SPA values were compared between the patients who underwent spontaneous vaginal delivery (SVD) and those who were submitted to unplanned obstetric intervention (UOI) due to prolonged or arrested labor (vacuum delivery or caesarean section). RESULTS: Overall, 129 women were included, and the mean birthweight of the neonates was 4,066 ± 263.03 g. SVD occurred in 63 patients (48.8%), whereas UOI due to prolonged or arrested labor was performed in 66 (51.2%), including 21 cases of vacuum delivery and 45 caesarean sections. The SPA was significantly smaller among women who underwent UOI than in those who achieved SVD (107.9 ± 13.4 vs. 120.7 ± 9.4°, p < 0.001). Furthermore, SPA width was inversely correlated with labor length (p < 0.001). Multivariable logistic regression analysis showed that a smaller SPA (OR 1.091, 95% CI 1.051-1.134, p < 0.001) and an increased birthweight (OR 1.002, 95% CI 1.000-1.004, p = 0.037) were independent risk factors for operative delivery. CONCLUSION: SPA measurement before labor is helpful in predicting the risk of operative delivery due to prolonged or arrested labor among nulliparous women delivering LGA fetuses.

Fetal head circumference and subpubic angle are independent risk factors for unplanned cesarean and operative delivery.

INTRODUCTION: The aim of this study was to ascertain whether combined ultrasound assessment of fetal head circumference (HC) and maternal subpubic angle (SPA) prior to the onset of labor may predict the likelihood of an unplanned operative delivery (UOD) in nulliparous women at term. MATERIAL AND METHODS: Prospective cohort study of singleton pregnancies in cephalic presentation. Pregnancies experiencing UOD secondary to fetal distress were excluded. HC was assessed transabdominally and SPA values were obtained from a reconstructed coronal plane on three-dimensional (3D) ultrasound performed translabially at 36-38 weeks of gestation. Maternal characteristics, HC expressed as multiple of median, and SPA were compared according to the mode of delivery. Logistic regression and receiver operating characteristics curve analyses were used to analyze the data. RESULTS: 597 pregnancies were included in the study. Spontaneous vaginal delivery occurred in 70.2% of the cases and UOD was required in 29.8%. There was no difference in pregnancy characteristics and birthweight between women who had a spontaneous vaginal birth compared with UOD. The HC multiple of median was larger (1.00 ± 0.02 vs. 1.03 ± 0.02, p ≤ 0.0001), whereas SPA was narrower in the UOD group (124.02 ± 13.64 vs. 102.61 ± 16.13, p ≤ 0.0001). At logistic regression, SPA (OR 0.91, 95% CI 0.89-0.93), HC multiple of median (OR 1.13, 95% CI 1.09-1.17) and maternal height (OR 0.95, 95% CI 0.92-0.99) were independently associated with UOD. When combined, the diagnostic accuracy of a predictive model integrating HC, SPA and maternal height was highly predictive of UOD with an area under the curve of 0.904 (95% CI 0.88-0.93). CONCLUSIONS: Ultrasound assessment of fetal HC and maternal SPA after 36 weeks of gestation can identify a subset of women at higher risk of UOD during labor, for whom early planned delivery might be beneficial.

Are There Differences in Placental Volume and Uterine Artery Doppler in Pregnancies Resulting From the Transfer of Fresh Versus Frozen-Thawed Embryos Through In Vitro Fertilization.

OBJECTIVE: To compare uterine artery pulsatility index (PI) and 3-dimensional (3D) placental volume values in first-trimester pregnancies conceived naturally or through in vitro fertilization (IVF) technique using either fresh or cryopreserved embryo and to relate these measurements with preeclampsia (PE) development. METHODS: Uterine artery PI and placental volume were measured at 11 + 0 to 13 + 6 weeks of gestation in 266 IVF pregnancies (139 women with fresh embryo and 127 women with frozen-thawed embryo transfer) and in 266 spontaneously conceived pregnancies matched for maternal age. Nulliparous women with singleton pregnancies were recruited. The mean, highest, and lowest uterine artery PI and placental volume values measured were converted to multiples of the expected normal median (MoM) adjusted for gestational age. The MoM values of IVF pregnancies were compared with those of the naturally conceived group and related to PE development. RESULTS: No differences were found in uterine artery PI MoM between the 3 groups. Placental volume was significantly lower than in both IVF groups when compared to the controls (fresh embryo IVF Z = 9.33; P ≤ .0001; frozen-thawed embryos IVF Z = 3.1; P = .04). The IVF pregnancies with fresh embryos showed placental volume MoM values significantly lower than in the frozen-thawed embryo IVF pregnancies (U = 5.4; P ≤ .0001). In fresh embryo IVF pregnancies developing PE placental volume values resulted lower than in the normotensive ones (U = 2.11; P = .03), while no differences were found for uterine artery PI values. CONCLUSION: First-trimester placental volume, as assessed by 3D ultrasound, is reduced in IVF pregnancies, and these differences are more marked in those obtained with fresh embryos than those obtained with cryopreservation. This may explain the better obstetrical and perinatal outcomes occurring with the former technique.

The effect of fetal sex on customized fetal growth charts.

OBJECTIVE: To evaluate the effect of fetal sex on singleton pregnancy growth charts customized for parental characteristics, race, and parity Methods: In a multicentric cross-sectional study, 8070 ultrasonographic examinations from low-risk singleton pregnancies between 16 and 40 weeks of gestation were considered. The fetal measurements obtained were biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Quantile regression was used to examine the impact of fetal sex across the biometric percentiles of the fetal measurements considered together with parents' height, weight, parity, and race. RESULTS: Fetal gender resulted to be a significant covariate for BDP, HC, and AC with higher values for male fetuses (p ≤ 0.0009). Minimal differences were found among sexes for FL. Parity, maternal race, paternal height and maternal height, and weight resulted significantly related to the fetal biometric parameters considered independently from fetal gender. CONCLUSION: In this study, we constructed customized biometric growth charts for fetal sex, parental, and obstetrical characteristics using quantile regression. The use of gender-specific charts offers the advantage to define individualized normal ranges of fetal biometric parameters at each specific centile. This approach may improve the antenatal identification of abnormal fetal growth.

The feasibility of using 5D CNS software in obtaining standard fetal head measurements from volumes acquired by three-dimensional ultrasonography: comparison with two-dimensional ultrasound.

OBJECTIVE: To evaluate the performance of a new software (5D CNS) developed to automatically recognize the axial planes of the fetal brain from three-dimensional volumes and to obtain the basic standard biometric measurements. The accuracy, reproducibility, and time required for analysis of 5D CNS were compared with that of two-dimensional (2D) ultrasound. METHODS: This was a prospective study of 120 uncomplicated singleton pregnancies undergoing routine second trimester examination. For every pregnancy standard biometric measurements including biparietal diameter, head circumference, distal lateral ventricle width, transverse cerebellar diameter and cisterna magna width were obtained using 2D ultrasound and three-dimensional (3D) ultrasound with 5D CNS software. Reliability and agreement of the two techniques were evaluated using intraclass correlation coefficients (ICCs) and proportionate Bland-Altman plots were constructed. The time necessary to complete the measurements with either technique was compared and intraobserver and interobserver agreements of measurements calculated. RESULTS: In 118/120 (98.3%), 5D CNS successfully reconstructed the axial diagnostic planes and calculated all the basic biometric head and brain measurements. The agreement between the two techniques was high for all the measurements considered (all ICCS > 0.920). The time necessary to measure the biometric variables considered was significantly shorter with 5D CNS (54 versus 115 s, p < 0.0001) than with 2D ultrasonography. No significant differences were found in 5D CNS repeated measurements obtained either by the same observer or by two independent observers. CONCLUSION: 5D CNS software allows us to obtain reliable biometric measurements of the fetal brain and to reduce the examination time. Its application may improve work-flow efficiency in ultrasonographic practices.

Ultrasonographic assessment of cervical length in pregnancies scheduled for a cesarean delivery: prediction of early spontaneous onset of labor.

AIM: To investigate whether the cervical length measured by transvaginal ultrasound at 35 to 36 weeks of gestation is predictive of spontaneous early onset of labor in pregnancies scheduled for elective cesarean section (CS). STUDY DESIGN: This was a prospective observational study on 167 women scheduled for elective CS at 39 weeks of gestation. The cervical length was measured ultrasonographycally at 35 to 36 weeks of gestation and the pregnancies characteristics were recorded. The presence or absence of spontaneous onset of labor before the time scheduled for elective CS was related to cervical length and pregnancies characteristics. RESULTS: Of the 167 pregnancies enrolled, 25 (14.97%) underwent early spontaneous onset of labor before the time scheduled for the elective CS. The cervical length was significantly shorter in these women when compared with those delivering with an elective CS (21 vs. 30 mm z=5.49 P<0.0001). The presence of ≥2 previous CS as an indicator for elective CS resulted a significant predictor of early onset of labor in univariate analysis (P=0.01). Multivariate logistic regression analysis showed that cervical length (adjusted odds ratio 1.40; 95% confidence interval (CI) 1.22-1.61; P≤0.0001) was the only predictor for the early onset of labor. The area under the receiver-operating characteristics curve for the prediction of early onset of labor was 0.844 (95% CI 0.738-0.950) for cervical length as test variable. Kaplan-Meier analysis demonstrated that a cervical length <24 mm was significantly associated with a short time interval to delivery (log rank test χ2=99,98; P≤0.0001). CONCLUSION: Cervical length at 35-36 weeks of gestation provides information about the likelihood of spontaneous early onset of labor in pregnancies scheduled for CS and may be useful in individualizing the gestational age for elective CS.

Does fetal macrosomia affect umbilical artery Doppler velocity waveforms in pregnancies complicated by gestational diabetes?

OBJECTIVES: We aimed to establish whether macrosomic fetuses in pregnancies complicated by gestational diabetes (GDM) show different Pulsatility Index (PI) values in umbilical artery (UA) than in non-macrosomic fetuses. METHODS: We considered 106 pregnant women with GDM. Doppler recordings of UA-PI were performed at 34-41 weeks and related to neonatal birthweight. Pregnancies were divided in two groups according to birthweight, macrosomic group (>4000 g) and controls (<4000 g), and according to birthweight centile, >90th centile and <90th centile. Differences in UA-PI and maternal and fetal characteristics between groups were tested. RESULTS: Mean UA-PI was significantly lower in newborns with birthweight >4000 g than in controls (PI = 0.69; 95% CI 0.64-0.74 versus PI = 0.87; 95% CI 0.84-0.90, p < 000.1). Mean UA-PI was significantly lower in newborns with birthweight centile >90th centile than in controls (PI = 0.79; 95% CI 0.74-0.84 versus PI = 0.87; 95% CI 0.83-0.90; t = 2.653; p = 0.01). Linear regression analysis revealed a significant correlation between UA-PI and neonatal birthweight and between UA-PI and neonatal birthweight centile. CONCLUSIONS: Macrosomic fetuses of pregnancies complicated by GDM show lower values of UA-PI compared with controls. Despite UA-PI results, a variable related to macrosomia its role in the management of these pregnancies remains to be established.

Modelling umbilical vein blood flow normograms at 14-40 weeks of gestation by quantile regression analysis.

OBJECTIVE: To construct reference limits for gestation of umbilical vein blood flow (UVBF) in normal singleton pregnancies between 14 and 40 weeks of gestation using quantile regression. METHODS: We ultrasonographycally examined 852 fetuses from low-risk pregnancies between 16 and 40 weeks of gestation in a prospective cross-sectional study. UV diameter and time-averaged maximum velocity (TAMXV) were measured in UV intra-abdominal portion by real time and Doppler ultrasonography. A semi-automatic measurement software was used to obtain UV diameter values. UVBF was then calculated from UV diameter and TAMXV measurements and expressed both as absolute value and as value normalized for fetal abdominal circumference (UVBF/AC). Individual centile values of the variables investigated were established by quantile regression in the gestational interval considered. In 50 cases UVBF was measured twice by the same investigator or by a second investigator and the intra- and inter-observer agreement were calculated. RESULTS: A significant increase in UV diameter, TAMXV, UVBF absolute value and UVBF/AC was evidenced in the gestational period considered. Growth charts were established based on these measurements. The intra- and inter-observer intraclass correlation coefficients resulted as 0.92 (0.87-0.96) and 0.89 (0.84-0.97), respectively, for UBVF. CONCLUSIONS: In this study we constructed UVBF charts using quantile regression in a large cohort of low-risk pregnancies. These charts offer the advantage of specific estimated regression parameters for each percentile, better defining the normal range of UVBF. This promises to be useful in the diagnosis and management of fetuses with abnormal fetal growth.