Reference values of fetal ultrasound biometry: results of a prospective cohort study in Lithuania.

PURPOSE: The aim of the study was to construct a reference range for the Lithuanian population for fetal biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC) and femur length (FL) and to compare them with the old local and current international reference values. METHODS: A prospective cross-sectional study was carried out in secondary referral centres Vilnius University Hospital Santariskiu Klinikos Centro Affiliate in 2008-2009 and Vilnius Maternity Hospital in 2009-2014. The fetal biometry of 556 fetuses between 12 and 42 weeks gestation was performed. BPD, OFD, HC, AC and FL were measured. The data were collected and the analysis was performed using statistical programs MS Excel, SPSS and Matlab. Different regression models were fitted to calculate the mean and standard deviation at each gestational age for each parameter. RESULTS: The biometric measurements of HC, BPD, OFD as well as AC and FL were performed for 556 fetuses. The centile charts, tables and regression formulae of the biometric parameters were constructed. The comparison of the current charts with those of other two studies revealed no significant differences of HC centiles. AC values were similar to those presented in the international study INTERGROWTH-21 and significantly higher in comparison to the study for the Lithuanian population conducted by Alisauskas (1980). FL values, especially in late pregnancy, were significantly smaller in the INTERGROWTH-21 study compared to our charts; however, there were no significant differences of the 50th centile compared to the results from Alisauskas. CONCLUSIONS: We have constructed and presented centile charts, tables and regression formulae for fetal biometry for the Lithuanian population and compared them with the results of two other studies. The significant differences between our centile charts and those from INTERGROWTH-21 imply the necessity to have local standards of fetal biometry, while the differences of our results from the older study in the same population show the importance of updating fetal biometry reference charts for every generation.

Fetal Tibial Artery Doppler in Late IUGR Fetuses: A Longitudinal Study.

INTRODUCTION: Late-onset intrauterine fetal growth restriction (IUGR) is a common pregnancy complication diagnosed in 5-10% of pregnant women worldwide. Under the impact of hypoxia, the fetus develops a protective mechanism of adaptive changes occurring in the cerebral circulation ("brain-sparing effect"). MATERIALS AND METHODS: We conducted detailed longitudinal Doppler examinations and the monitoring of the fetal condition in 53 IUGR fetuses. Doppler measurements of the pulsatility index in the fetal tibial (TA-PI), umbilical (UA-PI), and middle cerebral arteries (MCA-PI) were performed, and the cerebral placental ratio (CPR) was determined on a weekly basis from the 33rd week to the birth. RESULTS: The longitudinal analysis showed a significant increase in the TA-PI. The UA showed a plateau, but no increase was detected near term. The MCA-PI and CPR showed a progressive decrease in values from inclusion to delivery. Our findings indicate that the increase in the TA-PI was the first sign of the aggravating state of the fetus with the changes registered from the 35th week. The parameters of the UA-PI did not show significant changes, while the MCA and CPR became abnormal later from the 37th week. CONCLUSIONS: These observations can serve towards the development of guidelines for detecting the deteriorating signs and intervention timing in IUGR during late pregnancies.

Doppler Ultrasonography of the Fetal Tibial Artery in High-Risk Pregnancy and Its Value in Predicting and Monitoring Fetal Hypoxia in IUGR Fetuses.

Background and Objectives: Intrauterine growth restriction (IUGR) is the term used to describe a fetus whose estimated weight is less than the 10th percentile of its age growth curve. IUGR is the second most common cause of perinatal death. In many cases there is a deficiency in the standardization of optimal management, prenatal follow-up and timing of delivery. Doppler examination is the most sensitive test that can assess the condition of the fetus and indicate fetal intrauterine hypoxia. Numerous studies of the fetal intrauterine state focus on the umbilical artery and the fetal cerebral blood vessels, while the peripheral arteries have so far received insufficient attention. Materials and Methods: We present a case of an IUGR fetus monitored with a non-stress test (NST) and a Doppler examination of the fetal arteries (tibial, umbilical, middle cerebral and uterine) and the ductus venosus. In this case the first early sign of fetal hypoxia was revealed by blood flow changes in the tibial artery. Results: We hypothesize that peripheral vascular changes (in the tibial artery) may more accurately reflect the onset of deterioration in the condition of the IUGR fetus, such that peripheral blood flow monitoring ought to be employed along with other techniques already in use. Conclusion: This paper describes the clinical presentation of an early detection of late IUGR hypoxia and claims that blood flow changes in the tibial artery signal the worsening of the fetus's condition.

Influence of newborn head circumference and birth weight on the delivery mode of primipara: what is more important?

Objectives Aim of the study was to analyze the impact of head circumference (HC) and birth weight (BW) on the delivery mode and delivery outcomes. Methods Study population consisted of pregnancy, delivery and newborn data from 1,762 women, who delivered between 2004 and 2016 at University Hospital of Zurich (UHZ). Odds ratio (OR) with 95% confidence intervals (CI) were calculated for mode of delivery. Newborns were sorted into four groups according HC or BW. To evaluate the association between HC and delivery outcome, a descriptive analysis was performed. In addition reference charts of newborn HC at term were constructed. Results OR for instrumental delivery (ID) was 2.37 (CI 95%, 1.63-3.46), for C-Section (CS) 3.74 (CI 95%, 1.49-9.37) when HC >36 cm. OR for ID was 1.59 (CI 95%, 1.02-2.50), for CS 3.18 (CI 95% 1.08-9.350) when BW was >4,000 g. OR for ID was 2.15 (95% CI, 1.69-2.73), for CS 1.93 (95% CI, 0.89-4.18) when HC ≥36 cm and BW <4000 g. OR for ID was 2.23 (95% CI, 1.35-3.67), for CS 4.39 (95% CI, 1.48-12.99) when HC ≥36 cm and BW ≥4,000 g. HC ≥36 cm was defined as large in our study. Mothers with higher age and body mass index delivered babies with larger HC (p<0.05). Blood loss and duration of expulsion period and BW was associated with larger HC (p<0.05). Conclusions The rate of ID and CS increased in case of a larger HC and greater BW. However, the main prognostic factor for ID was size of HC: ≥36 cm, but not macrosomia.

Comparison of Current Swiss Fetal Biometry Reference Charts with Reference Charts from 1999. Are Fetuses Getting Bigger?

PURPOSE: To create current fetal biometry reference ranges and to compare them with references published in 1999, from the same local area in order to generate data for secular trend in fetal size. MATERIALS AND METHODS: Applying the same methodology as previously published, we calculated reference ranges for biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC) and femur length (FL) in 7863 patients examined at the obstetric clinics in a cross-sectional, prospective study in a university setting from January 2008 to December 2014. In order to compare the new reference ranges with our previously published data, we used Z-Scores and displayed the pick-up of fetal biometry data below the 5th and above the 95th percentile using the previously published reference charts. RESULTS: The comparison of the charts showed a minimal but clinically relevant increase in mean fetal body measures (BPD, HC, AC). Applying the 1999 charts to the new dataset, we would classify only 162 of 339 fetuses (47.8 %) to be correctly below the 5th percentile for AC and only 134 of 349 (38.4 %) fetuses were correctly below the 5th percentile for HC. On the other hand, the 1999 charts classified 426 instead of 332 fetuses to be above the 95th percentile for AC, which means an overestimation of 28.3 %. CONCLUSION: Applying a similar methodology, study collective and clinical setting, our new charts showed clinically relevant differences compared to the 1999 charts. The data suggest that within one generation fetuses are getting bigger and regular updates of fetal reference charts are needed.

Fetal biometry: Relevance in obstetrical practice.

Ultrasound imaging in obstetrics and gynecology dates back to 1958 when The Lancet published the first article about the use of ultrasonography for fetal and gynecological assessments. It is now almost inconceivable, 60 years later, to think of effective performance in obstetrics and gynecology without the variety of ultrasound, for example, real time imaging, power and color Doppler, 3D/4D ultrasonography, etc. Such examinations facilitate the assessment of intrauterine fetal growth and development during pregnancy, provide alerts about the risk of pre-eclampsia and preterm birth, help identify anatomic reasons for infertility, diagnose ectopic pregnancies, uterine, ovary and tubal pathology. Ultrasonography is also used for diagnostic and treatment procedures during pregnancy or for the treatment of infertility. This article is an overview of the development of fetal ultrasound, the methodology and interpretation of ultrasound in the assessment of intrauterine fetal growth and fetal biometry standards both worldwide and in Lithuania.

Pregnancy outcomes regarding maternal serum AFP value in second trimester screening.

AIM: The aim of this study was to evaluate the predictive value of α-fetoprotein in maternal serum (MS-AFP) as a marker for diverse pregnancy outcomes. METHODS: The study was based on pregnancy and delivery data from 5520 women between 1999 and 2014 at University Hospital of Zurich (UHZ). INCLUSION CRITERIA: both MS-AFP and pregnancy outcome were known for the same pregnancy. Pregnancy outcomes and characteristics such as fetal malformation, intrauterine fetal death (IUFD) and intrauterine growth retardation as well as maternal age, weight before pregnancy, gestational age (GA) at delivery, newborn weight, length and head circumference were analyzed with respect to the MS-AFP value. MS-AFP value was categorized into three groups: elevated MS-AFP>2.5 multiples of the median (MoM), normal 0.5-2.49 MoM and decreased <0.5 MoM. RESULTS: Newborn weight (g) and length (cm) were significantly lower in the elevated MS-AFP (P<0.001) group, and infants had 1 week lower GA at delivery (P<0.05). In the group of elevated MS-AFP (n=46), 26.1% of pregnancies were significantly related to adverse pregnancy outcomes, such as fetal malformations, fetuses small for gestational age (SGA) and IUFD. Adverse pregnancy outcomes of 5.6% were registered in the group of normal MS-AFP and 7.3% in the group of low MS-AFP (P<0.05). CONCLUSION: MS-AFP level in the second trimester is still an important indicator of fetal surface malformations; however, ultrasound still outweighs as a screening method. Nevertheless, pregnant women with elevated MS-AFP values and with no sonographically detected fetal malformations should additionally receive the third trimester ultrasound examination to exclude other possible complications of pregnancy.

Neurodevelopmental outcome in very low birthweight infants with pathological umbilical artery flow.

OBJECTIVE: To assess neurodevelopmental outcome during toddlerhood in very low birthweight (VLBW) infants with absent or reverse end-diastolic flow (AREDF) in the umbilical artery (UA) during pregnancy. DESIGN: Retrospective cohort study with matched control group. SETTING: Tertiary perinatal centre. PATIENTS AND OUTCOME MEASURES: We compared longitudinally collected data on neonatal and neurodevelopmental outcomes among 41 infants born in our institution from 1997 to 2010 with birth weight <1500 g and UA AREDF and 41 infants with prenatally normal UA Doppler parameters matched for gestational age, birth weight, sex and year of birth. We evaluated neurodevelopmental outcome at a median (range) corrected age of 23.3 (10.1-29.6) months using the Bayley scales of infant development, 2nd edition (BSID-II), and neurological examination. RESULTS: The mental development index in UA AREDF children (median (range) 84 (49-116)) was significantly lower than in controls (median (range) 91 (62-140)), including after adjustment for confounders. Intergroup differences in psychomotor development index (PDI; BSID-II) and the rate of cerebral palsy or minor neuromotor dysfunction were non-significant. CONCLUSIONS: VLBW infants with UA AREDF have a higher risk of poorer mental development during toddlerhood than controls matched for gestational age, birth weight, sex and year of birth. UA AREDF may be considered a prenatal predictor of poorer mental development in this population. Long-term follow-up studies with larger cohorts are needed to better evaluate the impact of this prenatal factor on later neurodevelopment.

Maternal and neonatal outcome of labour induction at term comparing two regimens of misoprostol.

AIM: To compare the efficacy and safety of two misoprostol dosing regimens for induction of labour in primiparous (1P) and multiparous (>1P) women. METHODS: Retrospective study of induction of labour using vaginal misoprostol 25 µg vs. 50 µg every 6 h in 942 women at a tertiary centre. The main outcome variables are induction-to-delivery interval, latency period duration, vaginal delivery within 24 h, and maternal and foetal safety outcome. RESULTS: With the 50 µg regimen, induction-to-delivery intervals were significantly shorter: 18.4 h vs. 24.6 h (1P) and 14 h vs. 17.9 h (>1P), as was latency period duration (by 5.4 and 4 h, respectively). Vaginal delivery within 24 h was significantly more frequent, as were non-reassuring foetal heart rate (1P: 20% vs. 14%) and tachysystole (1P: 31% vs. 11%; >1P: 21% vs. 7%). No uterine rupture was reported. Neonatal outcomes were similar except for significantly more frequent infant referral to neonatal intensive care in the >1P group receiving the 50 µg regimen (11% vs. 4%). CONCLUSION: Vaginal misoprostol 25 µg seems to maintain efficacy with more acceptable maternal and neonatal safety. As induction of labour is an off-label use for misoprostol, safety should be prioritised with the lower dosage regimen despite the longer induction-to-delivery interval.

Notes on a stick: use and acceptability of woman-held maternity notes.

OBJECTIVE: To provide expectant mothers with a USB stick containing their maternity notes, including ultrasound images, and to assess its use and acceptability versus conventional care with exclusively hospital-held notes. STUDY DESIGN: USB group: 200 women attending Zurich University Hospital Obstetrics Department for antenatal-to-postnatal care in 2006-2007. CONTROLS: 200 women attending the Obstetrics Department for delivery only, after receiving conventional antenatal care elsewhere. Women were interviewed using an essentially identical postpartum questionnaire for each group, with minor wording differences. MAIN OUTCOME MEASURES: Overall satisfaction with pregnancy and delivery, feeling of safety, interest in the pregnancy, partner involvement, usefulness of USB stick in emergencies, impact on smoking behaviour, data confidentiality concerns, pregnancy and infant outcome. Stepwise multiple regression was used to identify determinants of overall impressions of pregnancy and delivery. RESULTS: Of the USB group, 98.5% wished to repeat the USB experience in a subsequent pregnancy; of the controls, 86.5% would have appreciated the experience, and 18.0% could think of situations in their pregnancy (vacation, emergencies) where the stick would have helped; 7.5% of the USB group shared their stick data with a doctor outside the Department, and 80.5% felt safer having the stick available. Along with preterm delivery and mode of delivery, the USB stick was a significant determinant of the overall positive impression of pregnancy. Primary caesarean section was (inexplicably) more frequent in the USB group. CONCLUSION: The questionnaire confirmed that issuing women with their maternity notes on a USB stick is a major advance in patient empowerment, satisfaction and safety.

Puerperal symphysis fundus distance: normal values.

AIM: To measure puerperal symphysis fundus distance (SFD) by two manual methods and to calculate individual normal values. STUDY DESIGN: Prospective cohort study including women after single pregnancy without special problems in uterine involution. METHODS: SFD was daily measured on the 1(st)-5(th) postpartum days by counting the number of midwife's fingers put horizontally on the mother's abdomen and by a paper tape, respectively. Linear mixed model analysis was performed to determine SFD normal values. RESULTS: Independent variables determining the SFD on different days after delivery were the gestational age and the delivery mode (finger method) and the maternal age, body mass index (BMI), delivery mode and birth weight (tape method). Individual normal values were calculated by regression equation including the coefficients for the independent variables. CONCLUSION: Puerperal SFD values measured by tape have more independent variables than those measured by fingers and reflect better the actual situation of the patient. It should be verified whether values deviating from normal values of tape measurements may prevent postpartum complications.

Creating unbiased cross-sectional covariate-related reference ranges from serial correlated measurements.

Cross-sectional covariate-related reference ranges are widely used in clinical medicine to put individual observations in the context of population values. Usually, such reference ranges are created from data sets of independent observations. If multiple measurements per individual are available, then ignoring the within-person correlation between repeats will lead to overestimation of centile precision. Furthermore, if abnormal measurements have triggered more frequent assessment, the data set will be biased thus producing biased centiles. Where multiple measures per individual exist, the methods commonly used are either randomly or systematically to select one observation per individual or to model individual trajectories and combine these. The first of these approaches may result in discarding a large proportion of the available data and may itself cause bias and the latter requires the form of the changes within individuals to be characterized. We have developed an approach to the modeling of the median, spread, and skew across individuals using maximum likelihood, which can incorporate correlations between dependent observations. Heavily biased data sets are simulated to illustrate how the methodology can eliminate the biases inherent in the data collection process and produce valid centiles plus estimates of the within-person correlations. The "select one per individual" approach is shown to be liable to bias and to produce less precise centiles. We recommend that the maximum likelihood method incorporating correlations be used with existing data sets. Furthermore, this is a potentially more efficient approach to be considered when planning the future collection of data solely for the purposes of creating cross-sectional covariate-related reference ranges.

Newborn weight charts underestimate the incidence of low birthweight in preterm infants.

OBJECTIVE: The objective of the study was to compare sonographic fetal weight estimates with newborn weight charts and analyze the predictive accuracy of the ponderal index (PI) in preterm infants. STUDY DESIGN: We generated sonographic reference curves for fetal weight and PI estimates from a database of fetal biometric records from 12,589 term deliveries. We then plotted sonographic and newborn weight and PI of 2406 preterm newborns on these curves and compared them with published newborn weight charts. RESULTS: The third centiles of sonographic and newborn weights diverged markedly between 25 and 36 weeks of gestation and by more than 400 g at 32-33 weeks. In contrast, sonographic and newborn PI values were similar despite uncertainties as to fetal length. CONCLUSION: We suggest using sonographic reference fetal weights to screen preterm newborns for low birthweight. Uncertainties in fetal length threaten the reliability of the PI.

Fetoscopic closure of punctured fetal membranes with acellular human amnion plugs in a rabbit model.

OBJECTIVE: To explore a surgical plug formed from decellularized term human amnion membrane for fetoscopic closure of iatrogenic defects in fetal membranes in a rabbit model. METHODS: The study was performed in eight rabbit does. Punctures were created at midgestational day 23 by 14-gauge needle fetoscopy on surgically exposed rabbit amniotic sacs. The entry sites were fetoscopically plugged either with decellularized term human amnion membrane (n=10) or previously successful commercial collagen matrix foil (n=10), followed by their primary fixation with fibrin glue and myometrial suturing. Seven punctured sacs without any plugging and 31 sacs without any manipulation served as two reference groups. Amniotic integrity and fetal parameters were assessed at gestational day 30. RESULTS: We established a facile method to prepare sheets of decellularized term human amnion membrane and verified its nontoxicity and cell compatibility in vitro. Decellularized term human amnion membrane sheets could be delivered precisely and controlled by fetoscopy as compact plugs into amniotic defects. The surgical handling characteristics of decellularized term human amnion membrane were better than the commercial collagen matrix foil. Treatment with human decellularized term human amnion membrane was comparable to treatment with the collagen matrix with regard to efficiency in restoring amniotic integrity. Seventy-five percent and 71.4% of amniotic sacs treated with decellularized term human amnion membrane or the commercial collagen matrix foil, respectively, showed amniotic integrity, compared with 25% in the left-open study group. Histology at the 1 week experimental endpoint showed no evidence for inflammation or beginning of anatomic healing of grafted, decellularized term human amnion membrane. CONCLUSION: Fetoscopic delivery of plugs made of decellularized term human amnion membrane presents a potentially practical surgical method to restore amniotic integrity of punctured fetal membranes. LEVEL OF EVIDENCE: III.

Reference values for the weight of freshly delivered term placentas and for placental weight-birth weight ratios.

BACKGROUND: There is evidence for a correlation between placental weight and future chronic disease, notably hypertension and diabetes. However, there are no reference scales for placentas that are readily weighed in the delivery room. METHODS: This cross-sectional study generated reference values for the weight of freshly delivered untrimmed placentas, and placental weight-birth weight (pw/bw) ratios from a database of 11,141 uncomplicated singleton term pregnancies (37-42 weeks). The data analysis followed stringent validated and state of the art methodological recommendations. A regression model was fitted to estimate the mean and standard deviation for placental weight and pw/bw ratios at each week of gestational age. RESULTS: Reference scales, percentile tables and regression equations are presented for placental weights according to the mode of delivery and for pw/bw ratios. Mean placental weight from vaginal deliveries was 76 g lighter than from Caesarean sections (545+/-107 g versus 621+/-139 g, respectively, P<0.05). Mean placental weight increased by 60 g from 37 to 42 weeks irrespective of the mode of delivery. The pw/bw ratio decreased from 17.6 to 15.6 between 37 and 42 weeks. CONCLUSION: For the first time, reference values for freshly delivered term placental weights depending on the mode of delivery were generated. In the light of growing evidence for a correlation of placental weight with chronic diseases in later life, these values provide the possibility to judge placentas at site for abnormalities in weight and to estimate the potential risks for chronic diseases in later life.

Nuchal cords in term and postterm deliveries--do we need to know?

OBJECTIVE: To analyze the effect of nuchal cords on perinatal features at delivery of term and postterm pregnancies. METHODS: A total of 11,748 women with planned vaginal deliveries, including 9,574 term and 2,174 postterm deliveries, were analyzed for intrapartum events, clinical peripartum management, mode of delivery, and neonatal outcome. The presence of nuchal cords was diagnosed clinically at the time of delivery. Data were obtained from our perinatal database between 1995 and 2004 for retrospective analysis. RESULTS: The incidence of nuchal cords in term and postterm deliveries was 33.7% and 35.1%, respectively. Multiple nuchal cords were present in 5.8% of term and 5.5% of postterm deliveries. Intrapartum signs of fetal compromise were increased in all groups, albeit not all reaching statistical significance in postterm deliveries. Meconium staining was significantly increased only in multiple nuchal cords of postterm deliveries (42.1% compared with 30.1%, P < .05). Mode of delivery was unchanged in all nuchal cord groups. Unfavorable neonatal blood gas values were significantly more frequent in all nuchal cord groups. Nevertheless, 5-minute Apgar scores less than 7 were not more common, and admission to neonatal unit was not required more frequently. Neonatal mean birth weight was significantly lower in all nuchal cord groups. CONCLUSION: Nuchal cords do not influence clinical management at delivery, and neonatal primary adaption is not impaired. Our data show that ultrasonographic nuchal cord assessment is not necessary at the time of admission for delivery. LEVEL OF EVIDENCE: II-3.

Ultrasonographic fetal weight estimation: accuracy of formulas and accuracy of examiners by birth weight from 500 to 5000 g.

OBJECTIVE: To determine the accuracy of birth weight in different birth weight (BW) groups using widely accepted formulas for fetal weight estimation (EFW). The secondary purpose was to estimate the role of examiners on the accuracy of EFW. METHODS: The cross-sectional data were obtained from 5612 pregnant women. Fetal weight was estimated for each fetus using the formulas of Campbell and Wilkin, Shepard, 2 formulas of Hadlock and Merz. Inclusion criteria were: singleton pregnancy, complete ultrasound parameters, EFW obtained within the last week prior to delivery, the live born infant without congenital malformations or hydrops. RESULTS: The highest intraclass correlation coefficient and the most stable results in all BW groups were generated with both Hadlock formulas. Both Hadlock and Campbell formulas had the lowest percent errors (PE) in BW groups between <1500 g and 3500 g. Shepard and Merz formulas had lower PEs in BW groups between 3501 g and >4000 g. However in BW groups under 3500 g they were imprecise. The PE of EFW varied from -4.0 +/- 8.5% to 1.3 +/- 8.5% between examiners. CONCLUSIONS: Both Hadlock formulas showed the most stable results in all of the weight groups. There is also a need for routine evaluation of the accuracy of EFW for every examiner, to make suggestions, what fetal measurements must be improved to improve EFW.