Ductus venosus opens in high-risk pregnancies without signs of increased central venous pressure.

OBJECTIVES: It has been belived that changes in diastolic blood velocities in the fetal ductus venosus were due to increased central venous pressure secondary to increased fetal heart strain during hypoxia or heart failure. There have been recent reports of changes in ductus venosus blood velocity without signs of increased fetal heart strain. The aim of this evaluation was to compare blood velocity in the right hepatic vein as a marker of increased central venous pressure in relationship to changes in ductus venosus blood velocity. MATERIAL AND METHODS: Fifty pregnancies suspected of fetal growth resitriction were evaluated by Doppler ultrasound. Blood velocity was recorded in the right hepatic vein, ducus venosus and in the umbilical vein. Placental blood flow was also recorded in the uterine and umbilical arteries as well as the fetal middle cerebral artery. RESULTS: Increased umbilical artery pulsatility index was recorded in 19 fetuses and 20 has signes of brain sparing according to recordings in the middle cerebral artery. Abnormal blood velocity in the ductus venosus was recorded in 5 fetuses, none of these fetuses had an abnormal pulsatility in the right hepatic vein. CONCLUSIONS: Opening of the ductus venosus is not only related to fetal cardiac strain. This might indicate that the ductus venosus does not primarily open due to increased central venous pressure in moderate fetal hypoxia. Increased fetal cardiac strain might be a late event in the process of chronic fetal hypoxia.

Placental pulsatility index: a new, more sensitive parameter for predicting adverse outcome in pregnancies suspected of fetal growth restriction.

INTRODUCTION: The pulsatility indices of the umbilical and uterine arteries are used as the surrogate measures of utero-placental perfusion. Combining the two might simplify the evaluation of total placental vascular impedance, possibly improve prediction of adverse outcomes, and help identify pregnancies with suspected fetal growth restriction that need more intense surveillance. MATERIAL AND METHODS: Umbilical and uterine blood flow velocities were recorded using pulsed-wave Doppler in a longitudinal study of 53 low-risk pregnancies (248 observations) during 20-40 weeks of gestation. Pulsatility indices was calculated for each of these vessels. A new placental pulsatility index was constructed as: (umbilical artery pulsatility index + mean of the left and right uterine artery pulsatility indices)/2, and mean +2 SD defined as abnormal. Gestational age-specific reference percentiles were calculated for the second half of pregnancy and related to values obtained from 340 pregnancies with suspected intra-uterine growth restriction to test its ability to predict adverse pregnancy outcome. RESULTS: The placental pulsatility index was closely associated with gestational age and decreased with advancing gestation in normal pregnancy. The placental pulsatility index had a higher sensitivity and comparable specificity in predicting adverse outcome in pregnancies suspected of intra-uterine fetal growth restriction when compared with conventional umbilical and uterine artery pulsatility indices. CONCLUSIONS: The new placental pulsatility index, reflecting placental vascular impedance on both the fetal and maternal side of placenta, improves prediction of adverse outcome in pregnancies suspected of intra-uterine fetal growth restriction.

Increased pulsatility in the fetal ductus venosus is not related to altered cardiac strain in high-risk pregnancies.

OBJECTIVE: Blood flow velocity patterns in fetal veins are considered to reflect cardiac function, but have not been convincingly documented. The aim of this study was to generate reference values for fetal cardiac strain and compare it with results in fetuses with signs of increased venous pulsatility. METHODS: Cardiac four-chamber loops were prospectively stored and analyzed for strain and strain rate in a cohort of 250 healthy fetuses. The results were compared with recordings in 38 fetuses with increased vascular impedance in the umbilical artery, including several with abnormal blood flow velocities in the ductus venosus (DVs) and umbilical vein. RESULTS: In the control group, strain rate was slightly higher in the right ventricle, but strain and velocities were similar. There was a significant effect of frame rate on the values of strain and strain rate, but not on velocity. No differences in cardiac strain or strain rate were observed between the control group and the compromised fetuses. There was no correlation between changes in venous blood flow and cardiac strain. CONCLUSIONS: Increased venous pulsatility was not related to fetal cardiac strain. This might indicate that the DVs does not primarily open due to increased central venous pressure and that cardiac strain is affected late in the process of moderate fetal hypoxia.

Alterations in ductus venosus velocity indices in relation to umbilical venous pulsations and perinatal outcome.

INTRODUCTION: Abnormal blood velocity in the ductus venosus is more frequently detected than pulsations in the umbilical vein, but both are considered to be indicators of fetal compromise. The aim of this study was to investigate blood flow patterns in the ductus venosus and the association between individual blood velocity ratios and pulsations in the umbilical vein and perinatal outcome. MATERIAL AND METHODS: Retrospective cohort study on Doppler ultrasound examination of ductus venosus and umbilical venous blood velocity in 358 high-risk pregnancies. Ductus venosus blood velocity pattern was analyzed for pulsatility index and the following velocity ratios: S/ES, S/a and ES/a (where S is systole, ES is end-systole, and a is atrial contraction). Ductus venosus ratio z-scores were calculated and related to pulsations in the umbilical vein and adverse perinatal outcome. RESULTS: Systolic ratios in the ductus venosus were less frequently abnormal than ratios taking into account diastolic velocities, particularly at full-term. High S/ES, ES/a ratios and pulsatility index (z-score >2), were all related to presence of pulsations in the umbilical vein. Umbilical venous pulsations were the best indicator of adverse perinatal outcome. CONCLUSIONS: Changes in ductus venosus blood flow during systole occur more rarely than diastolic changes, and alterations in end-diastolic blood velocity in the ductus venosus might give false-positive indications of worsening fetal condition. Umbilical venous pulsations seem to better predict adverse outcome of pregnancy than do indices in the ductus venosus.

Investigations on atrial function in fetuses with signs of impaired placental function.

OBJECTIVE: Cardiac dysfunction has been shown in cases of placental insufficiency, but few reports exist on fetal atrial function. The aim of this study was to generate reference values for atrial strain and compare them to results in fetuses with signs of increased placental resistance and abnormal venous circulation. METHODS: Using a 2D speckle-tracking technique, velocity and strain of the fetal atrial walls were investigated in 250 healthy fetuses and in 40 fetuses with abnormal umbilical Doppler. Influences of gestational age, heart rate, and frame rate on the measurements were investigated and reference curves constructed. RESULTS: Strain and velocity were greater for the right atrial walls compared with the left, and velocity and strain rate increased with gestational age. Increased pulsatility of the ductus venosus and umbilical vein was not associated with altered right atrial function. CONCLUSIONS: 2D speckle-tracking analysis of fetal atrial wall movement seems to be feasible. Atrial function was preserved in fetuses with placental dysfunction, even in cases of increased venous pulsatility.

Uterine artery Doppler in high-risk pregnancies at 23-24 gestational weeks is of value in predicting adverse outcome of pregnancy and selecting cases for more intense surveillance.

OBJECTIVE: To assess the role of the placental arterial Doppler examination at 23-24 gestational weeks for predicting adverse perinatal outcome in high-risk pregnancies. DESIGN: Retrospective register study. SETTING: Skåne University Hospital in Malmö. POPULATION: Six hundred and forty-five women with high-risk pregnancies, without fetal malformations or chromosomal abnormalities. METHODS: Placental (uterine and umbilical artery) Doppler ultrasound examination at 23-24 gestational weeks. MAIN OUTCOME MEASURES: Adverse perinatal outcomes including preeclampsia, small-for-gestational age newborns (smaller than 3rd percentile or smaller than the 10th percentile), preterm delivery (<34 weeks or <37 weeks of gestation at delivery), cesarean section, admission to the neonatal intensive care unit and intra-uterine fetal death. RESULTS: Abnormal uterine artery Doppler values were detected in 45% of this high-risk group but abnormal umbilical artery Doppler indices were only seen in 3.7%. Adverse perinatal outcome increased significantly with increasing placental vascular impedance (p < 0.0001). There were seven cases of intrauterine fetal death and in five the uterine artery Doppler values at 23-24 weeks were abnormal. A strong correlation between abnormal uterine artery Doppler and preeclampsia was present, but not with other forms of hypertensive disorder. CONCLUSION: Placental Doppler screening at 23-24 weeks can be used in detecting pregnancies at risk of adverse outcome and in selecting cases for more intense surveillance. A surveillance plan is proposed based on Doppler screening at 23-24 weeks of gestation.

Fetal pulmonary and cerebral artery Doppler velocumetry in normal and high risk pregnancy.

UNLABELLED: Studies on fetal lung/brain circulation by means of power Doppler technique have suggested a marked reduction in lung perfusion in high-risk pregnancies as a sign of circulation redistribution. The ratio between lung/brain perfusion might therefore give a new method to predict fetal circulation centralization. OBJECTIVE: The aim of the present study was to obtain fetal lung and cerebral artery ratio in normal and high-risk pregnancies. STUDY DESIGN: Doppler samples from proximal right pulmonary artery blood velocities and middle cerebral artery (MCA) were recorded cross-sectionally in 228 normal singleton pregnancies at gestational age 22 to 40 weeks. MCA/right pulmonary artery pulsatility index (PI) ratio was calculated. Doppler samples from proximal right pulmonary artery and MCA were also recorded in 89 high-risk singleton pregnancies and the results related to perinatal outcome. RESULTS: In the normal controls, right pulmonary artery PI remained stable until 30 weeks of gestation with slight increase thereafter until term. The MCA to right pulmonary artery PI ratio increased between 22 and 28 weeks of gestation with the rapid fall towards term. In the high-risk pregnancies group, right pulmonary artery PI showed no significant correlation to perinatal outcome, but signs of brain-sparing in the MCA were correlated to all adverse outcome parameters. CONCLUSION: Velocimetry of the middle cerebral artery is better than velocimetry of right pulmonary artery in predicting adverse outcome of pregnancy The brain/lung PI ratio does not improve the prediction of adverse outcome of pregnancy.

Identification of pregnancies at increased risk of brachial plexus birth palsy - the construction of a weighted risk score.

OBJECTIVE: Since it is difficult to identify women at increased risk of fetal brachial plexus birth palsy (BPBP) during labor and delivery, we aimed to construct and validate a risk score. METHODS: A retrospective case-control study was undertaken in 2001 and 2006 in an urban context in Malmö, Sweden. A risk score was constructed for all women who had received routine municipal maternal health care at Skåne University Hospital (n = 10 459). The model was validated among all pregnant women with BPBP and controls in Sweden between 2006 and 2007. RESULTS: The likelihood of BPBP increased as the risk score rose: 3.1% of the women studied had a risk score ≥5, including 32.1% of the BPBP cases, where the risk showed a 38-fold increase, as compared to those with a risk score ≤1 (2/3 of the population). CONCLUSION: Our findings indicate that it is possible to identify women at increased risk of having a child with BPBP by using variables observable in advance of delivery.

Ultrasound measurements of umbilical cord transverse area in normal pregnancies and pregnancies complicated by diabetes mellitus.

OBJECTIVE: A voluminous umbilical cord has been described in diabetic pregnancies. The aim of this studywas to see if measurements of cord diameters might be of value in the evaluation of diabetic pregnancies and especially those suspected of a large for gestational age (LGA) fetus. METHODS: In an observational, prospective study umbilical cord areas and vessel diameters were measured between gestational age of 22 and 40 weeks in transverse ultrasound images of the central part of the cord in 141 normal and 135 diabetic pregnancies of which 30 were suspected of being LGA. Wharton's jelly area was calculated by subtracting the vessel area from the total transverse cord area. Normal reference curves were constructed for gestational age. RESULTS: Umbilical cord and Wharton's jelly areas increased with gestation. The vessel area leveled out at 32-33 weeks of gestation and the umbilical vein area decreased after 36 weeks of gestation. The umbilical cord parameters in diabetic pregnancies did not differ from controls. Cord areas were enlarged in 1/3 of the LGA fetuses. CONCLUSION: Umbilical cord area measurements are of limited value for the evaluation of diabetic pregnancies suspected having a LGA-fetus.

Characteristics and outcome of brachial plexus birth palsy in neonates.

AIM: To relate pregnancy characteristics to extent and reversibility of brachial plexus birth palsy (BPBP) in neonates. METHODS: Retrospective case-control study: newborns with a registered diagnosis of BPBP (n = 168) 1990-2005 were compared to data from a randomly selected control group (n = 1000). Characteristics were related to the level of injury, reversibility and outcome. RESULTS: Among 51,841 newborns, 168 cases with BPBP were found (incidence 3.2/1000 newborns/year). Extent and reversibility of lesion did not differ with respect to characteristics of mothers, foetuses or deliveries. Children with C5-C6 and C5-C6-C7 injuries had complete recovery in 86% and 38%, respectively. Global injuries (C5-Th1) always had permanent disability. Accelerators (foetal weight gain >35 g/day after 32 weeks of gestation) and foetuses with estimated weight deviation ≥ +22% at 32 weeks were at seven- and ninefold increased risk of BPBP. Parous women were at doubled risk as compared to nulliparous women. CONCLUSION: Maternal and foetal characteristics influence risk of BPBP, but not the extent of injury or reversibility of injury. Because of the high risk of permanent disability and modest risk of low Apgar or pH among newborns with BPBP, the recommendation of prompt delivery may need to be re-evaluated.

Multivascular Doppler surveillance in high risk pregnancies.

OBJECTIVES: Analysis of fetal arterial and venous Doppler predictability for adverse perinatal outcome. METHODS: Blood flow in the uterine, umbilical and middle cerebral arteries, umbilical vein, ductus venosus and Galen vein were examined with in 72 h of delivery in 88 high-risk pregnancies. The managing clinicians were only informed about the results of the umbilical artery Doppler. The Doppler results were correlated to adverse perinatal outcome. RESULTS: Doppler abnormalities were seen in both preterm and term pregnancies. Umbilical venous pulsations (n = 13) were strongly correlated to Apgar score <7 at 5 min, abnormal blood gases, need for ventilation assistance and operative delivery for fetal distress. Twenty-four fetuses had brain sparing in the middle cerebral artery, and forty-five had abnormal umbilical artery Doppler. These were correlated to admission in the neonatal intensive care unit, operative delivery and prematurity. Brain sparing in middle cerebral artery was also correlated to ventilation disturbances in the newborns. Abnormal ductus venosus blood velocity was only seen in 9 cases and not related to adverse outcome. Galen vein pulsations (n = 26) seem to appear earlier than pulsations in the umbilical vein and were not related to adverse outcome. conclusion: Umbilical vein pulsations were better correlated to adverse perinatal outcome than were other Doppler findings including ductus venosus.

Hepatic aminotransferases of normal and IUGR fetuses in cord blood at birth.

BACKGROUND: The accepted standard for assessing the wellbeing of the newborn is the Apgar score and blood gas analysis. However, the prediction of neonatal morbidity or mortality is limited. In small-for-gestation (SGA) fetuses at 18-38 weeks of gestation, pO(2) is <5th centile both in the umbilical artery and vein in 30%. In a previous study in singleton term neonates cardiac specific enzymes (B-type natriuretic peptide, BNP and cardiac troponin T, cTnT) are increased in growth-restricted fetuses compared with normals. AIMS: To test the hypothesis, that fetuses with intra uterine growth restriction (IUGR) have elevated AST (GOT) and ALT (GPT) aminotransferases as a result of hypoxic liver cell injury, and to establish references ranges. STUDY DESIGN: Prospective cohort study, serum of umbilical artery (n=156) and vein (n=180), 599 normal singletons at 37(+0)-42(+0)weeks, neonates with IUGR (n=41), analysis for pH, birthweight and maternal weight, spontaneous vs cesarean section, vein vs artery and for the sex. OUTCOME MEASURES: Aspartate aminotransferase (AST, GOT) and Alanine aminotransferase (ALT, GPT) were measured in normals and IUGR neonates. RESULTS: Neonates with IUGR (n=41) had AST values that were not different from the reference group, but had significantly lower ALT (-1.49, 95% CI -1.98 to -1.00 vs 0.14, 95% CI -0.42-0.13), (p<0.001), (Fig. 3). CONCLUSIONS: In neonates with IUGR, hypoxic hepatic injury markers in cord blood were not elevated. Rather, a substantially reduced ALT suggests a down-regulated hepatic activity.

Placental morphologic and functional imaging in high-risk pregnancies.

The placenta is vital for fetal growth and development. Improvement in ultrasound and magnetic resonance imaging have improved our understanding of placental morphology that can be important as in the case of placental accrete/percreta. Functional imaging is presently mainly performed by the use of Doppler ultrasound and can give information on placental perfusion, which can be vital for clinical diagnosis. This review summarizes the present knowledge on placental imaging and it's clinical value in high-risk pregnancies.

Abnormal uterine artery Doppler in pregnancies suspected of a SGA fetus is related to increased risk of recurrence during next pregnancy.

OBJECTIVE: To investigate if placental Doppler velocimetry can predict the recurrence of a small-for-gestational age (SGA) fetus in subsequent pregnancies. DESIGN: Retrospective study. SETTING: City cohort over 15 years attending a university hospital. METHODS: A total of 196 pregnancies suspected of a SGA fetus (<3rd percentile) evaluated by uterine and umbilical artery Doppler velocimetry. Blood velocity waveform was analyzed for pulsatility index (PI) as well as the uterine artery waveform for notching in early diastole. MAIN OUTCOME MEASURE: The occurrence of a SGA newborn during the succeeding pregnancy by Doppler results from the previous pregnancy. RESULTS: In the group of 196 pregnancies suspected for SGA, 27 (13.8%) delivered a SGA newborn in the following pregnancy. Thirty-seven (18.9%) of the 196 had an abnormally high PI in the uterine arteries in their first pregnancy, 12 (32.4%) of these delivered a SGA child in the next pregnancy (relative risk 3.44, p<0.001). The corresponding figure for those with normal uterine artery PI was 15 (9.4%). Abnormal umbilical artery Doppler was a worse predictor of recurrence of SGA (p=0.051). Uterine artery notching was not related to a SGA newborn during next pregnancy. CONCLUSION: The results suggest that abnormal uterine artery Doppler is related to increased risk of recurrence of SGA during the next pregnancy. This knowledge might provide the clinician with an opportunity to initiate preventive treatment and increase surveillance to women at risk during succeeding pregnancy.

Signs of fetal brain sparing are not related to umbilical cord blood gases at birth.

BACKGROUND: Fetal chronic hypoxia leads to centralization of circulation in order to spare the vital organs brain, adrenals and the heart. This can be documented by Doppler ultrasound. Increased blood velocity in the fetal middle cerebral artery (MCA) is an acknowledged sign of centralization of circulation in chronic hypoxia, and is called brain sparing. AIM: Our aim was to assess the relationship between signs of brain sparing in the MCA and umbilical cord blood gases at birth. STUDY DESIGN: A prospective study. SUBJECTS: Singleton 57 high-risk pregnancies (outcome was compared with 21 normal pregnancies). METHODS: MCA Doppler was performed within 24 h of elective caesarean section in high-risk pregnancies. Umbilical cord blood gases were analysed at birth. MAIN OUTCOME MEASURES: Cord blood gases were related to signs of centralization of fetal circulation in the MCA. RESULTS: No correlation between signs of brain sparing in the MCA and cord blood gases. Apgar score at 5'<7 was seen in three newborns, but only one of these had antenatal signs of brain sparing. Newborns with antenatal brain sparing were admitted more often (p<0.04) and had a longer duration of stay in NICU (p<0.03) compared to newborns without brain sparing. CONCLUSION: Decreased pulsatility index in MCA is an acknowledged sign of fetal centralization of circulation during chronic hypoxia. However, signs of brain sparing are not related to cord blood gases at birth, which might suggest that redistribution of fetal circulation can maintain normal blood gases for a long time during chronic hypoxia.

Biochemical tissue-specific injury markers of the heart and brain in postpartum cord blood.

OBJECTIVE: We sought to establish references ranges and to test the hypothesis that biochemical tissue-specific markers for the heart in umbilical cord blood of newborns with cardiac defects and intrauterine growth restriction (IUGR) are abnormal. STUDY DESIGN: A prospective study was conducted. Serum samples of the umbilical vein (n = 280) and artery (n = 156) from 599 healthy newborns at 37(+0)-42(+0) weeks of gestation were collected. Total creatine kinase (CK), CK-MB heart type (CK-MB), cardiac troponin T (cTnT), myoglobin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and S100 were measured. Reference ranges for each marker were constructed. Concentrations of tissue-specific markers from umbilical cord blood of neonates with cardiac defects (n = 10) and IUGR (n = 41) were plotted against the established reference ranges. RESULTS: Reference ranges for each studied marker were established for both umbilical artery and vein. In fetuses with cardiac defects, both NT-proBNP (4/6 [66%] in the artery, 7/10 [70%] in the vein) and cTnT (2/10 [20%] in the vein) were increased. In fetuses with IUGR in the vein, NT-proBNP (10/41 [24%]) and cTnT (5/41 [12%]) were increased, whereas S100 (9/41 [21%]) was decreased. CONCLUSION: In a subset of neonates with cardiac defects or growth restriction, irrespective of the pH at birth, tissue-specific injury markers for the heart in umbilical cord blood are abnormal.

Quantification of left to right shunt in patent ductus arteriosus by color Doppler.

Ultrasound is a reliable tool to diagnose patent ductus arteriosus in premature infants but no reliable noninvasive method exists to quantify ductal flow. The aim of this study was to quantify the size of the shunt via persistent ductus arteriosus from pixel counts in color Doppler flow images. A cotton band was placed around the ductus arteriosus of newborn lambs to adjust the magnitude of flow. For flow measurements, ultrasonic transit time flow probes were applied around the ascending aorta and ductus arteriosus. Twenty-four different flow states were attained in four newborn lambs. An Acuson Sequoia scanner equipped with a 7 MHz transducer was used to register Doppler data and images with maximal color distribution during diastole in the pulmonary artery longitudinal sections (PALS). Each image-pixel was matched with the color velocity bar and the pixels were assigned to the corresponding flow velocity. The total area showing color relative to the area of the PALS correlated well with the amount of ductal flow (r = 0.87, r(2) = 0.75, p < 0.001). When Qp/Qs was >1.4:1, more than 40% of the area in PALS in diastole exhibited color information. Similarly, the color pixel velocities squared correlated with the size of the shunt. Quantification of the percentage of pixels in a color Doppler registration via a computer-based analysis shows a high correlation with the size of ductal shunting.

TNF-alpha gene polymorphism and fetal Doppler velocimetry in intrauterine growth restriction.

OBJECTIVES: The intrauterine growth restriction (IUGR) frequently is a cause of fetal morbidity and mortality, and influences perinatal outcome. Several genes have been identified to explain aetiology of IUGR, beside others the gene coding for tumour necrosis factor alpha (TNF-alpha). DESIGN: To investigate frequency of AlwI polymorphism of TNF-alpha gene and its correlation with TNF-alpha level in maternal serum, Doppler velocimetry and perinatal outcome in pregnancies suspected for IUGR. SETTING: 42 pregnancies with IUGR and 50 matched healthy pregnant women were included in the study. Maternal venous blood samples were investigated in relationship to blood flow Doppler velocimetry in umbilical (UA) and middle cerebral (MCA) arteries. AlwI polymorphism was analysed using PCR/RFLP assays. TNF-alpha level was evaluated by immunoelectophoretic method. RESULTS: A higher frequency of mutated -238A alleles (13.1% vs. 7.0%) and genotypes containing at least one mutated -238A allele (23.8% vs. 14.0%) were found in the IUGR group. The tendency to the higher TNF-alpha level in IUGR subgroups with the presence of at least one mutated A allele (258.9+/-231.3 vs. 174.1+/-145.6 pg/ml) was detected. No statistical differences were detected for PI values in UA and MCA arteries considering particular genotypes (GG vs. GA + AA) separately in IUGR group. CONCLUSION: Increased UA vascular impedance and signs of brain sparing in MCA are related to IUGR and increased TNF-alpha level in maternal serum. AlwI polymorphism might play a role in IUGR aetiology and influence TNF-alpha expression in maternal serum, but was not related to Doppler velocimetry or with perinatal outcome.

Nuchal cord in post-term pregnancy - relationship to suspected intrapartum fetal distress indicating operative intervention.

Color Doppler Ultrasound was performed on 202 post-term pregnancies to detect the presence of a nuchal cord. A nuchal cord was diagnosed if the umbilical cord could be followed 360 degrees around the fetal neck. The results were not disclosed to the managing obstetrician, midwife, and patient. The perinatal outcome was analyzed according to Apgar score, umbilical cord artery and vein pH and base excess (BE), perinatal death, cesarean section, operative delivery for fetal distress (ODFD) and admission to neonatal intensive care unit (NICU). A nuchal cord was detected in 69 patients (34.2%). The incidence was not affected by parity or reduced amniotic fluid volume. There was no statistically significant increased risk for 1- and 5-min Apgar scores <7, umbilical artery pH <7.1, umbilical vein pH <7.20, umbilical artery base excess <-11, umbilical vein base excess <-11, perinatal death, cesarean section, ODFD or admission to NICU. Nuchal cord in post-term pregnancies is not associated with an increased risk for signs of fetal distress and operative intervention during labor and delivery.

Fetal biometry between 20-42 weeks of gestation for Polish population.

OBJECTIVE: Ultrasound estimating of fetal weight is one of the most frequent examinations during pregnancy. Hitherto, foreign fetometry curves have mostly been used in Poland as there are no national available reference charts that are based on ultrasound fetal biometry. The aim of the present study was to construct new charts based on ultrasound fetometry reference for Polish population. STUDY DESIGN: A group of 959 healthy volunteers with uncomplicated singleton pregnancy joined in a cross-sectional study. The study was designed prospectively to evaluate normal reference charts for fetal ultrasound measurements and estimated fetal weight. Four biometric parameters were studied: biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Estimated fetal weight (EFW) was calculated using Hadlock et al. formula from 1985. RESULTS: In the course of normal pregnancy an acceleration of growth rate was seen, but with a slight decline at the end of pregnancy. Reference curves for mean, 90th and 95th percentile were constructed for BPD, HC, AC and FL. Estimated fetal weight curves were outlined for both boys and girls. CONCLUSION: Reference charts for Polish population are similar to foreign curves. Less variation was seen in comparison with national charts based on postnatal weight. Ultrasound method seems to be better than birthweight curves especially in preterm pregnancies. This will improve the diagnosis of a small for gestational age newborn.