The role of the PLGF in the management of pregnancies complicated with fetal microsomia.

PURPOSE: To explore the contribution of maternal and fetal parameters in predicting the time interval between diagnosis and development of adverse events leading to delivery in singleton pregnancies complicated with fetal microsomia. METHODS: Prospective study on singleton pregnancies referred to a tertiary center because of suspicion of fetal smallness in the third trimester. The study cohort included cases with fetal abdominal circumference (AC) ≤ 10th centile or estimated fetal weight ≤ 10th centile or umbilical artery pulsatitlity index ≥ 90th centile. Development of pre-eclampsia, fetal demise, and fetal deterioration diagnosed by fetal Doppler studies or fetal heart rate monitoring and leading to delivery were considered as adverse events. Maternal demographics, obstetric history, blood pressure, serum PLGF, and fetal Doppler studies were explored as predictors of the time interval between the first visit to the clinic and the diagnosis of complications. RESULTS: In 59 women, the median incubation period from presentation to the clinic to an adverse event was 6, 2 weeks, whereas half of the pregnancies (52.5%) did not develop any adverse event. PLGF was the strongest predictor of adverse events. Both PLGF in raw values and PLGF MOM had equally good predictive ability (AUC 0.82 and 0.78 respectively). Optimal cut-off points were 177.7 pg/ml for PLGF raw values (sensitivity 83% and specificity 66.7%) and 0.277 MoM (sensitivity 76% and specificity 86.7%). On multiple Cox regression analysis, maternal systolic blood pressure, PLGF, fetal increased umbilical artery PI, and reduced CP ratio were independently associated with adverse events. Half of the pregnancies with low PLGF and only one in ten with high PLGF were delivered within two weeks after the initial visit. CONCLUSION: Half of the pregnancies carrying a small fetus in the third trimester will not develop maternal or fetal complications. PLGF is a strong predictor of adverse events that can be used to customize antenatal care.

The role of the PLGF in the prediction of the outcome in pregnancies with a small for gestational age fetus.

PURPOSE: To explore the value of measuring maternal serum PLGF in the prediction of the outcome of small for gestational age fetuses (SGA). METHODS: Singleton pregnancies referred with suspicion of SGA in the third trimester were included if they had: no indication for nor signs of imminent delivery, fetal abdominal circumference (AC) at or below the 10th centile and/or estimated fetal weight (EFW) at or below the 10th centile and/or umbilical artery pulsatility index (Umb-PI) at or above the 90th centile for gestation. Women with pre-eclampsia at presentation were excluded. Maternal blood was drawn at the first (index) visit and analyzed retrospectively. RESULTS: Fifty-one fetuses were examined. Multiple regression analysis showed that family history of microsomia, index EFW and PLGF were significant predictors of the birthweight centile; index femur length centile and PLGF were significant predictors of pre-eclampsia; PLGF and index systolic blood pressure were significant predictors of iatrogenic preterm delivery < 37 weeks, whereas PLGF and index EFW were significant predictors of birthweight ≤ 5th centile and admission to the neonatal intensive care unit. For all outcomes, the addition of maternal-fetal parameters did not improve the prediction compared to PLGF alone. Using a cutoff of 0.3 MoM for PLGF would identify 94.1% of the pregnancies with iatrogenic preterm delivery and/or intra-uterine death and all of the cases that developed pre-eclampsia, for a screen positive rate of 54.9%. Women with PLGF ≤ 0.3 MoM had a poor fetal/maternal outcome (iatrogenic preterm delivery, pre-eclampsia, intra-uterine death) in 61.5% of cases. CONCLUSION: In pregnancies complicated by SGA, PLGF identifies a very high-risk group that may benefit from intense surveillance.

Screening vs. no screening for preterm delivery in low-risk singleton pregnancies: comparison by propensity score analysis.

PURPOSE: To compare the effect of a policy of screening for spontaneous preterm delivery (SPD) by transvaginal cervical length (CL) measurement versus a no screening policy in the prevention of severe prematurity. METHODS: Retrospective study on low-risk singleton pregnancies examined at 20-24 weeks. Two cohorts, one with SPD screening and the other without screening, were matched using propensity analysis to create the study groups. Women with short CL were treated with vaginal progesterone and/or cervical cerclage/pessary. The outcomes examined were SPD < 32 weeks (SPD 32) and SPD between 20 and 32 weeks (SPD 20-32). RESULTS: Screening for SPD was associated with a significant reduction in the rate of SPD at less than 32 weeks (0.3 vs. 0.8%, p = 0.001 in the screened and no screened pregnancies, respectively) and in the rate of SPD 20-32 (0.3 vs. 0.9%, p = 0.005 in the screened and no screened pregnancies, respectively). After adjusting for maternal age, parity, body mass index, smoking and mode of conception, the screening group had significantly lower hazard for SPD 20-32 (HR = 0.36, 95% CI: 0.18-0.75, p = 0.006) and SPD32 (HR = 0.39, 95% CI: 0.19-0.82, p = 0.013). CONCLUSION: Screening for SPD by transvaginal CL measurement in mid-pregnancy may reduce the incidence of severe prematurity in low-risk singleton pregnancies.

Very short cervix in low-risk asymptomatic singleton pregnancies: Outcome according to treatment and cervical length at diagnosis.

INTRODUCTION: The aim of this study was to explore the outcome of low-risk singleton pregnancies with very short cervical length (CL ≤15 mm) according to method of treatment and CL at diagnosis. MATERIAL AND METHODS: Retrospective study on singleton pregnancies devoid of risk factors for spontaneous preterm delivery identified in the course of universal screening programs by vaginal sonography at 20-24 weeks of gestation to have very short CL ≤ 15 mm. RESULTS: The study group consisted of 233 pregnancies with CL ≤ 15 mm of which 88 had cervical cerclage inserted and the remaining 145 were treated with vaginal progesterone. Mean CL at diagnosis was significantly shorter in the cerclage group (5 mm) compared with the progesterone group (12 mm). Regardless of treatment there was no difference in the rate of spontaneous preterm delivery at <32 weeks of gestation in women with CL ≥ 9 mm at screening (11% and 12% in the cerclage and progesterone groups, respectively). In contrast, in the subgroup with CL ≤ 8 mm cervical cerclage resulted in significantly lower rates of spontaneous preterm delivery at <32 weeks of gestation compared with progesterone treatment (20% and 45%, respectively, P = .009) and the median gestational age at birth was significantly greater (37 weeks vs 36 weeks, respectively, P = .013). CONCLUSIONS: The majority of asymptomatic singleton pregnancies with short CL will remain undelivered until 32 weeks of gestation whether treated with progesterone or cerclage. Women with extreme cervical shortening appear to benefit more from cervical cerclage.

Cervical length at 11-40 weeks: unconditional and conditional longitudinal reference ranges.

INTRODUCTION: Our aim was to establish unconditional and conditional longitudinal reference ranges for cervical length throughout pregnancy. MATERIAL AND METHODS: Prospective longitudinal study. In singleton pregnancies repeated cervical length measurements were carried out by transvaginal ultrasound throughout gestation. Multilevel modeling was applied to establish cervical length reference ranges from 11 to 40 weeks. RESULTS: In all, 4397 women contributed to 13 765 cervical length measurements. A linear mixed effects random intercept-random slope model was fitted to the data. Mean cervical length had a negative non-linear polynomial association with gestational age. Unconditional ranges were developed. Terms that allow the construction of personalized cervical length charts conditional to a previous measurement were calculated. CONCLUSIONS: We constructed longitudinal reference charts for cervical length in singleton pregnancies. Cervical length should be adjusted according to specific gestational-age-dependent ranges. Individualization of cervical assessment is feasible by the application of charts conditional to previous measurements.

Predicting fetal growth deviation in parous women: combining the birth weight of the previous pregnancy and third trimester ultrasound scan.

AIM: To investigate the value of the birth weight of the previous pregnancy (BW1) alone and combined with the third trimester ultrasonographically estimated fetal weight (EFW) and Doppler studies in the prediction of small (SGA) and large for gestational age (LGA) neonates in the index pregnancy (BW2). METHOD: Some 1298 parous women with uncomplicated singleton pregnancies who had a third trimester ultrasound scan were considered as samples in this retrospective cohort study. Maternal and pregnancy characteristics, BW1, EFW, umbilical artery, and middle cerebral artery pulsatility indices were investigated as predictors of SGA and LGA. RESULTS: BW1, maternal weight, mode of conception, and smoking status were associated with BW2 (R2=0.39) with BW1 being the strongest predictor (R2=0.37). The addition of EFW conferred significant improvement (R2=0.63), whereas the addition of the Doppler indices did not. The sensitivity of BW1 alone in the prediction of SGA was 75% for 25% screen positive rate and increased to 92% with the addition of EFW. The equivalent figures for LGA were 68% and 93%, respectively. CONCLUSIONS: BW1 used as a continuous variable is predictive of growth deviations in the index pregnancy. Incorporating EFW enhanced the sensitivity for the detection of both conditions.

Prediction of Preterm Delivery by Late Cervical Length Measurement after 24 Weeks.

OBJECTIVE: To examine the value of the cervical length (CL) measurement at 24-30 gestational weeks in the prediction of spontaneous preterm delivery (SPD) between 30 and 34 weeks (SPD34) and between 34 and 37 weeks (SPD37). METHODS: We performed a prospective cross-sectional study. CL was measured once by transvaginal ultrasound examination between 24 and 30 weeks. RESULTS: The study sample consisted of 1,180 low-risk singleton pregnancies. 10 women (0.85%) had a SPD34 and 60 (5.08%) had a SPD37. CL was shorter (p < 0.001) in the women who had a SPD34 (median 11 mm) compared to the women who delivered after 34 weeks (median 31 mm). CL was shorter (p < 0.001) in the women who had a SPD37 (median 22 mm) compared to the women who delivered after 37 weeks (median 31 mm). CL predicted SPD34 (OR = 0.837, R² = 0.2768, AUC = 0.9406, p < 0.001) and SPD37 (OR = 0.907, R² = 0.1085, AUC = 0.7584, p < 0.001). The model achieved a sensitivity of 70.0 and 38.3% for 10% false-positive rate for SPD34 and SPD37, respectively. CONCLUSIONS: CL after 24 weeks is significantly shorter in women destined to have a SPD. In low-risk singleton pregnancies CL performs very well in predicting SPD34 and adequately in predicting SPD37.

Towards detecting open spina bifida in the first trimester: the examination of the posterior brain.

INTRODUCTION: Our aim was to examine the value of indirect signs of open spina bifida in the mid-sagittal view of the posterior brain at the 11-13 weeks' ultrasound examination and to summarize the current evidence for the first-trimester diagnosis of spina bifida. METHODS: This was a prospective study in routine obstetric population. The presence of four almost parallel lines (four-line view) in the posterior brain was recorded. Biparietal diameter (BPD), intracranial translucency (IT) and cisterna magna (CM) were measured. The ratio of IT to CM (R ratio) was calculated. RESULTS: 2,491 pregnancies were examined prospectively. Updated reference ranges for IT and CM were constructed. There were 3 cases with open spina bifida, and the four-line view was abnormal in 2 of them. The abnormal fetuses had smaller BPD as well as pronounced reduction in the CM and increase in the R ratio. DISCUSSION: Examination of the posterior brain was feasible in all fetuses in the setting of the routine 11-13 weeks' ultrasound examination. Indirect signs of spina bifida are visible in the mid-sagittal view of the posterior brain, and the assessment of these structures can be a reliable tool in the early identification of this abnormality.

Screening for birth weight deviations by second and third trimester ultrasound scan.

OBJECTIVE: The aim of this article was to predict small for gestational age (SGA, at or less than the fifth birth weight percentile) and large for gestational age (LGA, at or greater than the 95th birth weight percentile) fetuses by using maternal and fetal parameters from the second and third trimester ultrasound examinations. METHOD: This article is a retrospective cohort study on 1979 singleton pregnancies that had a routine 20 to 24 weeks anomaly and a 30 to 34 weeks growth ultrasound scans. SGA delivered before 30 gestational weeks were excluded. RESULTS: Second trimester estimated fetal weight (EFW2 ), uterine arteries pulsatility index (PI), and maternal pregnancy characteristics were predictive for SGA (SGA second trimester model: R(2) = 0.225, area under the curve [AUC] = 0.815) and LGA (LGA second trimester model: R(2) = 0.203, AUC = 0.793). Third trimester EFW (EFW3 ), EFW2 , uterine arteries PI2 , umbilical PI, and maternal pregnancy characteristics improved the prediction of SGA (SGA combined model: R(2) = 0.423, AUC = 0.896) and LGA (LGA combined model: R(2) = 0.383, AUC = 0.882). Contingent screening with risk stratification by the second trimester model performed equally well for SGA (AUC = 0.882) and LGA (AUC = 0.861) as the combined models. CONCLUSION: Second trimester model performs well in the prediction of SGA and LGA. The addition of third trimester scan offers substantial improvement. Contingency screening is feasible with similar effectiveness.

Fetal volume at 11-14 gestational weeks: reference ranges and association with first trimester biochemical and biophysical markers.

AIMS: To establish reference ranges for fetal volume (FV) measured by three-dimensional ultrasound (3D-US) at 11-14 weeks of gestation and to examine the possible association of FV with maternal/pregnancy characteristics and biochemical parameters. METHODS: Prospective observational study on 240 fetuses at 11-14 weeks. FV was measured by 3D-US using Virtual Organ Computer-Aided Analysis. Pearson correlation coefficient (cc) and regression analysis were used. RESULTS: FV increased exponentially with crown rump length and was unrelated to maternal weight (cc=-0.137, P=0.071), age (cc=0.009, P=0.899), parity (0.76), smoking status (t-test, P=0.149) and mode of conception (t-test, P=0.8). Z-scores (z) of FV was not associated with z-mean uterine artery pulsatility index (cc=-0.026, P=0.733), log10 multiples of the median (MoM) free beta human chorionic gonadotrophin (cc=0.002, P=0.982), delta value (d) of nuchal translucency (cc=0.072, P=0.331) and d-fetal heart rate (cc=0.009, P=0.902), z-FV was significantly positively correlated with log10 MoM pregnancy associated plasma protein-A (PAPP-A; regression coefficient=1.420976, R2=0.0957, P<0.0001). CONCLUSIONS: FV is strongly related to PAPP-A even after adjustment for crown rump length with a mechanism unrelated to placental perfusion. FV is independent of the vast majority of first trimester parameters; hence, it is a promising marker of early fetal growth.

Development and validation of a prognostic model to predict birth weight: individual participant data meta-analysis.

Objective: To predict birth weight at various potential gestational ages of delivery based on data routinely available at the first antenatal visit. Design: Individual participant data meta-analysis. Data sources: Individual participant data of four cohorts (237 228 pregnancies) from the International Prediction of Pregnancy Complications (IPPIC) network dataset. Eligibility criteria for selecting studies: Studies in the IPPIC network were identified by searching major databases for studies reporting risk factors for adverse pregnancy outcomes, such as pre-eclampsia, fetal growth restriction, and stillbirth, from database inception to August 2019. Data of four IPPIC cohorts (237 228 pregnancies) from the US (National Institute of Child Health and Human Development, 2018; 233 483 pregnancies), UK (Allen et al, 2017; 1045 pregnancies), Norway (STORK Groruddalen research programme, 2010; 823 pregnancies), and Australia (Rumbold et al, 2006; 1877 pregnancies) were included in the development of the model. Results: The IPPIC birth weight model was developed with random intercept regression models with backward elimination for variable selection. Internal-external cross validation was performed to assess the study specific and pooled performance of the model, reported as calibration slope, calibration-in-the-large, and observed versus expected average birth weight ratio. Meta-analysis showed that the apparent performance of the model had good calibration (calibration slope 0.99, 95% confidence interval (CI) 0.88 to 1.10; calibration-in-the-large 44.5 g, -18.4 to 107.3) with an observed versus expected average birth weight ratio of 1.02 (95% CI 0.97 to 1.07). The proportion of variation in birth weight explained by the model (R2) was 46.9% (range 32.7-56.1% in each cohort). On internal-external cross validation, the model showed good calibration and predictive performance when validated in three cohorts with a calibration slope of 0.90 (Allen cohort), 1.04 (STORK Groruddalen cohort), and 1.07 (Rumbold cohort), calibration-in-the-large of -22.3 g (Allen cohort), -33.42 (Rumbold cohort), and 86.4 g (STORK Groruddalen cohort), and observed versus expected ratio of 0.99 (Rumbold cohort), 1.00 (Allen cohort), and 1.03 (STORK Groruddalen cohort); respective pooled estimates were 1.00 (95% CI 0.78 to 1.23; calibration slope), 9.7 g (-154.3 to 173.8; calibration-in-the-large), and 1.00 (0.94 to 1.07; observed v expected ratio). The model predictions were more accurate (smaller mean square error) in the lower end of predicted birth weight, which is important in informing clinical decision making. Conclusions: The IPPIC birth weight model allowed birth weight predictions for a range of possible gestational ages. The model explained about 50% of individual variation in birth weights, was well calibrated (especially in babies at high risk of fetal growth restriction and its complications), and showed promising performance in four different populations included in the individual participant data meta-analysis. Further research to examine the generalisability of performance in other countries, settings, and subgroups is required. Trial registration: PROSPERO CRD42019135045.

Performance of the ultrasound examination in the early and late third trimester for the prediction of birth weight deviations.

OBJECTIVES: This study aimed to define the optimal gestational age in the third trimester, early (30-33 weeks + 6 days) versus late (34-37 weeks), for performing an ultrasound examination for fetal biometry to predict birth weight deviations: small for gestational age (SGA ≤ 5th centile) and large for gestational age (LGA ≥ 95th centile) neonates. METHODS: We used an observational cross-sectional study in uncomplicated singleton pregnancies that had a third trimester ultrasound for fetal biometry and umbilical and middle cerebral fetal Doppler studies. Estimated fetal weight and fetal Doppler parameters were the examined variables for the prediction of SGA and LGA. RESULTS: Three thousand six hundred ninety women had an early examination, and 2288 women had a late one. For a screen-positive rate of 10%, estimated fetal weight achieved 58% and 53.4% sensitivity for the prediction of SGA [area under the curve (AUC) = 0.8578, p < 0.001] and LGA (AUC = 0.8547, p < 0.001), respectively, by the early examination. Accordingly, the sensitivities significantly increased to 75.2% and 63.2% for the prediction of SGA (AUC = 0.9074, p < 0.001) and LGA (AUC = 0.8782, p < 0.001), respectively, by the late examination. The inclusion of the Doppler indices did not improve the predictive models. CONCLUSIONS: A late third trimester ultrasound was superior in the prediction of SGA and LGA, and this improvement was more pronounced for the prediction of SGA.

Reproducibility study of crown-rump length and biparietal diameter measurements in the first trimester.

OBJECTIVE: This study aims to investigate the intra-observer and inter-observer variability of crown-rump length (CRL) and biparietal diameter (BPD) measurements in the first trimester. METHODS: A prospective observational study on 592 fetuses between 8 and 14 gestational weeks was conducted. Intra-class correlation coefficients (ICCs) were computed, and Bland-Altman analysis was carried out. RESULTS: The ICCs (95% confidence interval) and the 95% limits of agreement, expressed as a percentage of the average, for CRL's intra-observer and inter-observer variability were 0.979 (0.974-0.982, p < 0.001), +8.53% to -8.376%, and 0.968 (0.952-0.978, p < 0.001), +9.06% to -7.69%, respectively. The corresponding figures for BPD were 0.981 (0.977-0.984, p < 0.001), +7.41% to -7.51%, and 0.968 (0.952-0.978, p < 0.001), +6.65% to -7.25%. After conversion in days, the ICCs and 95% limits of agreement for CRL's intra-observer and inter-observer variability were 0.983 (0.980-0.986, p < 0.001), +2.88% to -2.84%, and 0.971 (0.957-0.980, p < 0.001), 2.83% to -2.60%, respectively. The corresponding figures for BPD were 0.982 (0.979-0.986, p < 0.001), +3.36% to -3.40%, and 0.968 (0.953-0.978, p < 0.001), +3.06% to -3.38%. CRL's standard deviation of the differences increased with gestation for intra-observer (r = 0.289, p < 0.001) and inter-observer (r = 0.197, p = 0.023) variability. CONCLUSION: The BPD and CRL are highly reproducible measurements. CRL's measurement error increased with the magnitude of CRL, whereas BPD's reproducibility was not affected by gestational age.

Assessment of the posterior brain at 11-14 weeks for the prediction of open neural tube defects.

OBJECTIVE: To evaluate the routine midsagittal view of the posterior brain at the 11-13 weeks' ultrasound examination, for predicting open neural tube defects. METHODS: Posterior brain was examined midsagittally for normality of the four-line view (upper and lower border of the brain stem, the choroid plexus of the fourth ventricle and the occipital bone). Intracranial translucency and cisterna magna (CM) were measured. RESULTS: The posterior brain was assessed in 1330 cases. The four-line view was normal in all but one case. In the two cases of open spina bifida contained in the study population, intracranial translucency was within normal range. The CM and the four-line view were normal in the first case, whereas in the second case, the four-line view was abnormal, and CM was obliterated and impossible to measure. No other cases of abnormal four-line view were observed in the study population. CONCLUSION: Obliteration of the CM appears to be the most consistent early sign of open neural tube defects. Attention should focus on either measuring the cisterna magna or simply observing the presence of four lines in the midsagittal view of the posterior brain. However, these early signs of brain herniation are not present in all abnormal cases.

Third trimester ultrasound for the prediction of the large for gestational age fetus in low-risk population and evaluation of contingency strategies.

OBJECTIVE: Evaluation of the effectiveness of third trimester fetal biometry and Doppler studies in predicting the birth of a large for gestational age neonate (LGA ≥ 95(th) centile). Assessment of the value of integrated models (combining maternal characteristics, first trimester parameters, third trimester fetal biometry) and the usefulness of contingency strategies. METHOD: Observational cross-sectional study on 2308 uncomplicated singleton pregnancies examined at 11 to 14 weeks and at 30 to 34 weeks. RESULTS: Ultrasound estimated fetal weight (EFW, area under the curve (AUC) = 0.83) was the best single predictor of LGA. Maternal weight, delta nuchal translucency and EFW were independent predictors for the integrated model, but the latter was not statistically better (AUC = 0.84) than using EFW alone. The detection rates for LGA were 72.5% and 73.7% for a 25% screen positive rate, by EFW and the third trimester integrated model respectively. A contingency strategy of rescanning 50% of the population in the third trimester according to the risk estimation by a first trimester prediction model results in detection rate of 64.7% for LGA for the same 25% screen positive rate (AUC = 0.78). CONCLUSIONS: Third trimester ultrasound is an effective screening modality for identifying fetal macrosomia. A contingency strategy utilizing first trimester parameters can reduce the need for unnecessary examinations.

First trimester prediction of small- and large-for-gestation neonates by an integrated model incorporating ultrasound parameters, biochemical indices and maternal characteristics.

OBJECTIVE: To identify maternal/pregnancy characteristics, first trimester ultrasound parameters and biochemical indices which are significant independent predictors of small-for-gestational age (SGA) and large-for-gestational age (LGA) neonates. DESIGN: Retrospective cross-sectional study. SETTING: Two fetal Medicine Units. POPULATION: 4 702 singleton pregnancies presenting for screening for chromosomal abnormalities by nuchal translucency and maternal serum biochemistry at 11-14 weeks. METHODS: Reference ranges for birthweight applied to our population were constructed by the Royston and Wright method. Multiple logistic regression was applied to develop first trimester prediction models for SGA and LGA. MAIN OUTCOME MEASURES: Birth of SGA or LGA neonate. RESULTS: Maternal height, parity, smoking, assisted conception, delta crown-rump length, delta nuchal translucency, free beta human chorionic gonadotrophin and pregnancy-associated plasma protein-A were significant independent predictors of SGA. Maternal weight and height, smoking, delta crown-rump length and delta nuchal translucency were significant independent predictors of LGA. Models for SGA (AUC=0.7296, CI: 0.69-0.76, p<0.0001) and LGA (AUC=0.6901, CI: 0.65-0.72, p<0.0001) were derived, applicable to routine obstetric population at low risk for these conditions. For 20% screen positive rate the modeling achieves sensitivities of about 55% for SGA and 48% for LGA neonates. CONCLUSION: Prediction for birthweight deviations is feasible using data available at the routine 11-14 weeks' examination. Delta CRL and delta nuchal translucency were significant independent predictors for both SGA and LGA.

The Incidence of the Agenesis of Fetal Ductus Venosus at the 11-13 Weeks' Ultrasound Examination.

OBJECTIVE: The objective is to examine the incidence of agenesis of fetal ductus venosus (DV) at the routine ultrasound examination at 11-13 weeks. MATERIALS AND METHODS: This is a retrospective study on women presenting for screening for chromosomal abnormalities. The fetal DV was routinely examined by color Doppler in the sagittal view. RESULTS: Out of 8,304 fetuses examined, there were 13 cases of DV agenesis (0.15%). The umbilical vein drainage was intra-hepatic in two-thirds of the cases, and all resulted in normal live births. In the remaining one-third of cases, the umbilical vein drained to the inferior vena cava and all had a poor outcome because of aneuploidies, cardiac defects, and Noonan syndrome. CONCLUSION: Fetal DV agenesis occurs in about one in 650 fetuses and the majority of cases have a benign course and a favorable outcome. Failure to identify the DV should prompt a detailed ultrasound examination, identification of the drainage site of the umbilical vein, and genetic testing.

Cervical length changes from the first to second trimester of pregnancy, and prediction of preterm birth by first-trimester sonographic cervical measurement.

OBJECTIVES: The purpose of this study was to examine the evolution of cervical length from the first to second trimester of pregnancy and the value of first-trimester cervical measurement in the prediction of preterm delivery. METHODS: We conducted a longitudinal prospective study. Cervical length was measured by transvaginal sonography at 11 to 14 weeks (Cx1), 16 to 19 weeks (Cx2), and 20 to 24 weeks (Cx3). RESULTS: Eight hundred singleton pregnancies were studied. The median cervical lengths were 33 mm for Cx1 and 31 mm for Cx2 and Cx3. Significant independent predictors for cervical length were maternal weight, height, and history of cervical surgery for Cx1, maternal height, history of cervical surgery, and history of preterm delivery for Cx2, and history of cervical surgery, history of first-trimester miscarriage, and history of spontaneous preterm delivery for Cx3. Mean cervical length shortening was 2.36 mm between Cx1 and Cx3. In the subgroups of women with previous cervical surgery and history of previous preterm birth, cervical shortening was significantly more prominent. The median Cx1 was significantly shorter in the women who subsequently delivered preterm; Cx1 predicted preterm delivery before 34 weeks (odds ratio, 0.746; 95% confidence interval, 0.649-0.869) and preterm delivery before 32 weeks (odds ratio, 0.734; 95% confidence interval, 0.637-0.912). CONCLUSIONS: Cervical length in the first trimester depends on maternal characteristics and a history of cervical surgery. The cervix exhibits minimal changes from 11 to 24 weeks for most women, although the shortening is more prominent in women with a history of cervical surgery or preterm delivery. First-trimester cervical length measurement can predict preterm delivery.

Reproducibility of cervical length measurement throughout pregnancy.

OBJECTIVES: To assess the intra- and interobserver variability of cervical length (CL) measurement in the three trimesters of pregnancy. METHODS: Prospective observational study. Transvaginal CL measurement was performed by two operators ignorant of each other's results. Two methods of measurement were assessed: the straight line method (SL = from internal to external cervical os along the endocervical mucosa) and the two-line method (TL = the sum of two lines following the curvature of the endocervical canal). RESULTS: There were 236 sets of CL measurements of which 96 (40.7%), 73 (30.5%), and 67 (28.8%) were performed in the first, second, and third trimesters of pregnancy, respectively. Intra- and interobserver variability was excellent for both methods (ICC 0.90) and was not influenced by gestational age. Mean difference was 1 mm (LOA -4 to -3 mm) for the same examiner and 1 mm as well between examiners (LOA -5 to -7 mm). Mean CL was slightly longer for the 2-L method (33 mm, SD = 5.2) compared to the SL method (31.4 mm, SD = 4.9). There was significantly more bias in the difference between methods the longer the CL measurement was (p <.001). CONCLUSIONS: CL measurement shows excellent intra- and interobserver variability across gestation and the variability of the measurement is not influenced by gestational age or CL length for either method. The TL method produces slightly longer values.