The vertebroplacental ratio as an alternative to the cerebroplacental ratio in the evaluation of the fetus at the end of pregnancy.

OBJECTIVE: Low cerebroplacental ratio (CPR) near term has emerged as a marker of fetal adverse outcome. The aim of this study was to evaluate the predictive accuracy of an alternative ratio using the vertebral artery (VA) (vertebroplacental ratio or VPR) for acid-base status at birth. METHODS: This was a prospective cohort study of 1470 pregnancies undergoing an ultrasound assessment of the umbilical artery, middle cerebral artery and VA Doppler beyond 34 weeks' gestation within 14 days of delivery. The CPR multiples of the median (MoM) and VPR MoM were calculated to adjust for gestational age. The relationship between the fetal Dopplers and the umbilical cord pH (arterial and venous) was evaluated statistically, and depicted graphically using three-dimensional (3D) trend surfaces, 2D contour graphs and ROC curves. RESULTS: All the studied parameters were poorly associated with neonatal acid-base status, although this association was slightly better for venous pH. The importance of BW centile was smaller than that of CPR and VPR MoM, however, both hemodynamic parameters were similarly associated with neonatal pH. CONCLUSIONS: Concerning fetal surveillance near term, the importance of cerebroplacental hemodynamics surpasses that of BW. Furthermore, in the evaluation of fetal wellbeing VPR behaves as a valid alternative to CPR.

Progression of Doppler changes in early-onset small for gestational age fetuses. How frequent are the different progression sequences?

OBJECTIVE: To evaluate the progression of Doppler abnormalities in early-onset fetal smallness (SGA). METHODS: A total of 948 Doppler examinations of the umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV), belonging to 405 early-onset SGA fetuses, were studied, evaluating the sequences of Doppler progression, the interval examination-labor at which Doppler became abnormal and the cumulative sum of Doppler anomalies in relation with labor proximity. RESULTS: The most frequent sequences were that in which only the UA pulsatility index (PI) became abnormal (42.1%) and that in which an abnormal UA PI appeared first, followed by an abnormal MCA PI (24.2%). In general, 71.3% of the fetuses followed the classical progression sequence UA→MCA→DV, mostly in the early stages of growth restriction (84.1%). In addition, the UA PI was the first parameter to be affected (9 weeks before delivery), followed by the MCA PI and the DV PIV (1 and 0 weeks). Finally, the UA PI began to sum anomalies 5 weeks before delivery, while the MCA and DV did it at 3 and 1 weeks before the pregnancy ended. CONCLUSIONS: In early-onset SGA fetuses, Doppler progression tends to follow a predictable order, with sequential changes in the umbilical, cerebral and DV impedances.

Doppler study of the fetal vertebral artery in small for gestational age fetuses with intrauterine growth restriction.

OBJECTIVES: The purposes of this study were to evaluate the Doppler resistive index of the fetal vertebral artery in small for gestational age (SGA) fetuses and to examine the ability of the vertebral artery resistive index in the diagnosis of intrauterine growth restriction (IUGR). METHODS: A total of 437 Doppler examinations of the vertebral and umbilical artery resistive indices were performed in 437 fetuses between 26 and 41 weeks' gestation. According to birth weight, fetuses were classified into 5 groups: 1, above the 10th percentile; 2, between the 10th and 5th percentiles; 3, between the 5th and 3rd percentiles; 4, below the 3rd percentile; and 5, below the 3rd percentile with an umbilical artery resistive index above the 95th percentile. Subsequently, vertebral artery resistive index values were converted into multiples of the median, and box and whisker charts were generated to evaluate differences. Finally, receiver operating characteristic curves were calculated to assess the accuracy of the vertebral artery resistive index for predicting IUGR and a low Apgar score. RESULTS: Compared to normally grown fetuses, vertebral artery resistive index values were lower in fetuses with birth weight below the 3rd percentile, and this difference was greater in fetuses with birth weight below the 3rd percentile and Doppler anomalies of the umbilical artery. The receiver operating characteristic analysis showed that the vertebral artery resistive index diagnosed SGA fetuses and low Apgar scores poorly. However, it performed better in cases of severe IUGR with high umbilical artery resistive index values. CONCLUSIONS: Preliminary data show that the vertebral artery resistive index diminishes in growth-restricted SGA fetuses. Doppler examination of the vertebral artery seems to identify a group of fetuses with brain sparing and severe IUGR.

Outcome of fetuses with diagnosis of isolated short femur in the second half of pregnancy.

Objectives. To assess the outcome of fetuses with isolated short femur detected at 19-41 weeks and determine to what extent this incidental finding should be a cause of concern in fetuses with a normal previous follow-up. Methods. 156 fetuses with isolated short femur were compared with a control group of 637 fetuses with normal femur length. FL values were converted into Z-scores and classified into 4 groups: control group: Z-score over -2, group 1: Z-score between -2 and -3, group 2: Z-score between -3 and -4, and group 3: Z-score below -4. FL values were plotted with the curves representing Z-scores -2, -3, and -4. To assess fetal outcome, the frequency of SGA, IUGR, abnormal umbilical Doppler (AUD), Down's syndrome, and skeletal dysplasia was determined for each group after delivery, and the relative risk in comparison with the control group was obtained. Finally, ROC curves were drawn in order to evaluate the FL diagnostic ability for the conditions appearing with increased frequency. Results. SGA, IUGR, and AUD were more frequent in the fetuses with short femur. Conversely, none of them presented Down's syndrome or skeletal dysplasia. According to ROC analysis, FL measurement behaved as a good diagnostic test for SGA and IUGR. Conclusions. A short femur diagnosis in a fetus with an otherwise normal follow-up determines just a higher risk of being small (SGA or IUGR).

Doppler impedance changes at the fetal brain vessels in a pregnancy affected with a multiple combination of uteroplacental anomalies.

A fetus with a very rare five-fold combination of uteroplacental anomalies, bicornuate uterus, short cervix with cervical incompetence, multilobed placenta succenturiata, accessory cotyledon within the cervical funneling, and umbilical cord insertion into the anomalous cervical cotyledon, presented an early and marked decrease at the vertebral and middle cerebral arteries Doppler resistances. This cerebral low-impedance state, usually found before labor, and considered an adaptive mechanism developed to protect the fetus at term from labor asphyxia, was present for an unknown reason at 20 weeks. After the patient was treated with vaginal progesterone, the cervix shortening improved and markedly, at the same time, the cerebral vascular resistances increased and maintained an adequate for gestational age impedance until delivery at 34 weeks. As the described uteroplacental anomalies determined a high risk of preterm delivery, due to cervical dilation, cord compresion, and placental haemorrhage, these fluctuating brain vascular changes might be the result of the fetal adaptation to the changes preceding an imminent delivery.

Fetal vertebral artery Doppler reference values at 19-41 weeks of gestation.

OBJECTIVES: To establish Doppler reference values for the fetal vertebral artery resistance index (VA RI), pulsatility index (VA PI) and peak systolic velocity (VA PSV), and describe their normal ratios to the umbilical artery (UA) throughout the second and third trimester of pregnancy. METHODS: Between 19 and 41 weeks of gestation, 484 ultrasound examinations of the fetal VA and UA were performed on singleton pregnant women with uncomplicated pregnancies. The VA was examined at the anatomical point where the artery surrounds the lateral masses of the atlas between the first cervical vertebra and the occipital bone, and values were obtained for the VA RI, VA PI and VA PSV. The 10th, 50th and 90th percentiles were subsequently generated for these parameters and their ratios to the UA. RESULTS: The VA RI and VA PI reached their maximum values at the end of the second trimester. Both indexes subsequently decreased due to an increase in the diastolic flow. Conversely, the VA PSV values increased progressively until the end of gestation. As for the VA/UA ratios, the RI and PI were higher in the middle of the third trimester and decreased slightly afterwards. On the other hand, the PSV increased progressively until the end of pregnancy. CONCLUSIONS: The fetal VA can be visualized with Doppler ultrasound as early as 19 weeks' gestation. In this study, reference values of the VA RI, PI and PSV and their ratios to the UA during the second half of pregnancy have been provided for fetal research. However, future work is necessary to further explore the possible applications of VA Doppler examination in fetal medicine.

Bicervical normal uterus with normal vagina and anteroposterior disposition of the double cervix.

We report a very uncommon uterine anomaly consisting on a normal uterus, a double cervix with an anteroposterior disposition, and absence of vaginal septum. A 36-years-old woman with one child and absence of past reproductive disorders was examined for a routine checkup. Clinical and transvaginal ultrasound examinations showed a normal uterus with a double cervix disposed in an anteroposterior fashion with the absence of vaginal septum. A review of the theories concerning müllerian fusion is done, and implications of this case in relation with these theories are discussed. This is the first case of a normal uterus with a double cervix situated in an anteroposterior fashion and absence of vaginal septum. This case is in concordance with theories that consider the fusion of the caudal part of Müllerian ducts to be the result of a complex process. It proves that at least in some cases the most caudal part of müllerian ducts is fused in an anteroposterior disposition.