Recommendations of the AGG (Working Group for Obstetrics, Department of Maternal Diseases) on How to Treat Thyroid Function Disorders in Pregnancy.

Objective These recommendations from the AGG (Committee for Obstetrics, Department of Maternal Diseases) on how to treat thyroid function disorder during pregnancy aim to improve the diagnosis and management of thyroid anomalies during pregnancy. Methods Based on the current literature, the task force members have developed the following recommendations and statements. These recommendations were adopted after a consensus by the members of the working group. Recommendations The following manuscript gives an insight into physiological and pathophysiological thyroid changes during pregnancy, recommendations for clinical and subclinical hypo- and hyperthyroidism, as well as fetal and neonatal diagnostic and management strategies.

Incarceration of the Gravid Uterus - a Rare Condition not to be Missed.

BACKGROUND: Incarceration of a gravid uterus (IGU) is a rare manifestation in obstetrics that may be associated with serious complications. CASE: We report on a 29-year-old patient at 34+2 weeks' gestation who presented with HELLP syndrome. IGU had been initially diagnosed in our department at 23+6 weeks' gestation. Urgent cesarean section was performed taking into account the specific characteristics of IGU. A healthy premature child was born. With the prior knowledge of IGU no complications during delivery occurred and mother and child had favorable outcomes. CONCLUSION: IGU is a rare condition in pregnancy that should not be overlooked. Early diagnosis and treatment of IGU can prevent serious complications to the mother and child during pregnancy and delivery. In this report, we discuss the specific peculiarities of an incarcerated uterus that need to be considered in this regard. HINTERGRUND: Ein Uterus incarceratus ist eine seltene Manifestation in der Geburtshilfe, welche mit schwerwiegenden Komplikationen einhergehen kann. FALL: Wir berichten über eine 29-jährige Patientin, die sich mit 34+2 Schwangerschaftswochen (SSW) mit einem HELLP-Syndrom in unserer Klinik vorgestellt hat. Die Erstdiagnose des inkarzerierten Uterus wurde in unserer Klinik mit 23+6 SSW gestellt. Aufgrund unserer Vorkenntnis über diese Diagnose konnte nun die dringend indizierte Sectio caesarea unter Berücksichtigung der spezifischen Merkmale in modifizierter Technik durchgeführt werden. Es wurde ein gesundes Frühgeborenes geboren. Es traten während der Geburt keine Komplikationen auf und Mutter und Kind hatten einen günstigen Verlauf. SCHLUSSFOLGERUNG: Ein Uterus incarceratus ist eine seltene Manifestation in der Schwangerschaft, welche nicht übersehen werden sollte. Eine frühzeitige Diagnose und Behandlung kann schwerwiegende Komplikationen für Mutter und Kind während der Schwangerschaft und unter der Geburt verhindern. Wir diskutieren die spezifischen Besonderheiten eines Uterus incarceratus, die hierbei zu berücksichtigen sind.

[COVID-19 in Pregnancy - a Risk for the Unborn Child?] / COVID-19 in der Schwangerschaft: Ursache für eine intrakranielle Blutung bei einem Frühgeborenen?

Geburtskliniken werden zunehmend mit an Covid-19 erkrankten Schwangeren konfrontiert. Dies stellt Geburtshelfer vor große Herausforderungen, da einige Fragestellungen noch nicht ausreichend wissenschaftlich erforscht sind. Über Covid-19 während der Schwangerschaft und seine Auswirkungen auf das ungeborene und neugeborene Kind ist nicht viel bekannt.

Percent error of ultrasound examination to estimate fetal weight at term in different categories of birth weight with focus on maternal diabetes and obesity.

BACKGROUND: Sonography based estimate of fetal weight is a considerable issue for delivery planning. The study evaluated the influence of diabetes, obesity, excess weight gain, fetal and neonatal anthropometrics on accuracy of estimated fetal weight with respect to the extent of the percent error of estimated fetal weight to birth weight for different categories. METHODS: Multicenter retrospective analysis from 11,049 term deliveries and fetal ultrasound biometry performed within 14 days to delivery. Estimated fetal weight was calculated by Hadlock IV. Percent error from birth weight was determined for categories in 250 g increments between 2500 g and 4500 g. Estimated fetal weight accuracy was categorized as accurate ≤ 10% of birth weight, under- and overestimated by > ± 10% - ± 20% and > 20%. RESULTS: Diabetes was diagnosed in 12.5%, obesity in 12.6% and weight gain exceeding IOM recommendation in 49.1% of the women. The percentage of accurate estimated fetal weight was not significantly different in the presence of maternal diabetes (70.0% vs. 71.8%, p = 0.17), obesity (69.6% vs. 71.9%, p = 0.08) or excess weight gain (71.2% vs. 72%, p = 0.352) but of preexisting diabetes (61.1% vs. 71.7%; p = 0.007) that was associated with the highest macrosomia rate (26.9%). Mean percent error of estimated fetal weight from birth weight was 2.39% ± 9.13%. The extent of percent error varied with birth weight with the lowest numbers for 3000 g-3249 g and increasing with the extent of birth weight variation: 5% ± 11% overestimation in the lowest and 12% ± 8% underestimation in the highest ranges. CONCLUSION: Diabetes, obesity and excess weight gain are not necessarily confounders of estimated fetal weight accuracy. Percent error of estimated fetal weight is closely related to birth weight with clinically relevant over- and underestimation at both extremes. This work provides detailed data regarding the extent of percent error for different birth weight categories and may therefore improve delivery planning.

Symptom Burden and Factors Associated with Acute Respiratory Infections in the First Two Years of Life-Results from the LoewenKIDS Cohort.

Acute respiratory infections (ARIs) are the most common childhood illnesses worldwide whereby the reported frequency varies widely, often depending on type of assessment. Symptom diaries are a powerful tool to counteract possible under-reporting, particularly of milder infections, and thus offer the possibility to assess the full burden of ARIs. The following analyses are based on symptom diaries from participants of the German birth cohort study LoewenKIDS. Primary analyses included frequencies of ARIs and specific symptoms. Factors, which might be associated with an increased number of ARIs, were identified using the Poisson regression. A subsample of two hundred eighty-eight participants were included. On average, 13.7 ARIs (SD: 5.2 median: 14.0 IQR: 10-17) were reported in the first two years of life with an average duration of 11 days per episode (SD: 5.8, median: 9.7, IQR: 7-14). The median age for the first ARI episode was 91 days (IQR: 57-128, mean: 107, SD: 84.5). Childcare attendance and having siblings were associated with an increased frequency of ARIs, while exclusive breastfeeding for the first three months was associated with less ARIs, compared to exclusive breastfeeding for a longer period. This study provides detailed insight into the symptom burden of ARIs in German infants.

Influence of Sonographic Fetal Weight Estimation Inaccuracies in Macrosomia on Perinatal Outcome.

OBJECTIVE: To evaluate the influence of inaccurate sonographic fetal weight estimation in macrosomia on the mode of delivery and neonatal outcome (NO). METHODS: In 14 633 pregnancies between 2002 and 2016, this retrospective study evaluated the association between sonographic fetal weight estimation, true birth weight (BW), mode of delivery (primary cesarean section [pCS], secondary cesarean section, vaginal delivery, and operative vaginal delivery rates) and NO parameters (5-min Apgar < 7, pH < 7.1, neonatal intensive care unit [NICU] admission, shoulder dystocia). Singleton pregnancies > 37 + 0 weeks with ultrasound-estimated fetal weight (EFW) within 7 days before delivery were included. The study population was divided into four groups: Group 1 (false-negative): EFW < 4000 g/BW ≥ 4000 g; Group 2 (true-positive): EFW ≥ 4000 g/BW ≥ 4000 g; Group 3 (false-positive): EFW ≥ 4000 g/BW < 4000 g; and Group 4 (true-negative): EFW < 4000 g/BW < 4000 g. RESULTS: As expected, the highest secondary cesarean section (sCS) rate was found in Group 2 (true-positive) (30.62 %), compared with only 17.68 % in Group 4 (true-negative). The sCS rate in the false-positive Group 3 was significantly higher (28.48 %) in comparison with the false-negative Group 1 (21.22 %; OR 1.48; 95 % CI, 1.16 to 1.89; P = 0.002). In comparison with the true-negative Group 4, univariate analyses showed significantly higher rates for sCS in all other groups: odds ratio (OR) 2.06 for Group 2 (95 % CI, 1.74 to 2.42; P < 0.001), 1.85 for Group 3 (95 % CI, 1.54 to 2.22, P < 0.001), and 1.25 for Group 1 (95 % CI, 1.05 to 1.49; P < 0.01). No significant differences were found for NO between Groups 1 and 3 for the parameters 5-min Apgar < 7 (P = 0.75), pH < 7.1 (P = 0.28), or NICU admission (P = 0.54). However, there was a significantly higher chance for shoulder dystocia in Group 1 compared with Group 3 (OR 4.58; 95 % CI, 1.34 to 24.30; P = 0.008). CONCLUSION: Sonographic EFW inaccuracies in fetal macrosomia appear to have a greater impact on the mode of delivery than birth weight itself. Underestimation of fetal weight may be associated with a higher probability of shoulder dystocia.

Induction of Labour. Guideline of the DGGG, OEGGG and SGGG (S2k, AWMF Registry No. 015-088, December 2020).

Aim The aim of this official guideline published and coordinated by the German Society of Gynaecology and Obstetrics (DGGG) in cooperation with the Austrian Society of Gynaecology and Obstetrics (OEGGG) and the Swiss Society of Gynaecology and Obstetrics (SGGG) is to provide a consensus-based overview of the indications, methods and general management of induction of labour by evaluating the relevant literature. Methods This S2k guideline was developed using a structured consensus process which included representative members from various professions; the guideline was commissioned by the guidelines commission of the DGGG, OEGGG and SGGG. Recommendations The guideline provides recommendations on the indications, management, methods, monitoring and special situations occurring in the context of inducing labour.

Recommendations of the AGG (Task Force for Obstetrics, Section Maternal Diseases) on the Management of Maternal Hepatitis B, C and D Infection in Pregnancy.

These statements and recommendations should provide appropriate information about maternal and fetal routes of infection, screening, detection of risk factors, diagnostic procedures, treatment, birth planning and peripartum and postpartum management of maternal hepatitis infection and offer pointers for prenatal counselling and routine clinical care on delivery wards.

The cumulative impact of parity on the body mass index (BMI) in a non-selected Lower Saxony population.

OBJECTIVES: During the last decade obesity has been continuously rising in adults in industrial countries. The increased occurrence of perinatal complications caused by maternal obesity poses a major challenge for obstetricians during pregnancy and childbirth. This study aims to examine the association between parity, pregnancy, birth risks, and body mass index (BMI) of women from Lower Saxony, Germany. METHODS: This retrospective cohort study examined pseudonymized data of a non-selected singleton cohort from Lower Saxony's statewide quality assurance initiative. Mothers were categorized according to BMI as normal weight (18.5 to <25 kg/m2) or obese (≥30 kg/m2). RESULTS: Most of the mothers in this study population were either in their first (33.9%) or second pregnancy (43.4%). The mean age of women giving birth for the first time was 28.3 years. Maternal age increased with increasing parity. The proportion of pregnant women with a BMI over 30 was 11% in primiparous women, 14.3% in second para, 17.3% in third para and 24.1% in fourth para or more women. Increasing parity was positively correlated with the incidence of classical diseases related to obesity, namely diabetes mellitus, gestational diabetes, hypertension, pregnancy-related hypertension and urinary protein excretion. An increased risk of primary or secondary cesarean section was observed in the obese women, particularly during the first deliveries. CONCLUSIONS: There is a positive and significant correlation between parity and increased maternal BMI. The highest weight gain happens during the first pregnancy. The rate of operative deliveries and complications during delivery is increased in obese pregnant women.

Fetal Weight Estimation Using Automated Fractional Limb Volume With 2-Dimensional Size Parameters: A Multicenter Study.

OBJECTIVES: To develop new fetal weight prediction models using automated fractional limb volume (FLV). METHODS: A prospective multicenter study measured fetal biometry within 4 to 7 days of delivery. Three-dimensional data acquisition included the automated FLV that was based on 50% of the humerus diaphysis (fractional arm volume [AVol]) or 50% of the femur diaphysis (fractional thigh volume [TVol]) length. A regression analysis provided population sample-specific coefficients to develop 4 weight estimation models. Estimated and actual birth weights (BWs) were compared for the mean percent difference ± standard deviation of the percent differences. Systematic errors were analyzed by the Student t test, and random errors were compared by the Pitman test. RESULTS: A total of 328 pregnancies were scanned before delivery (BW range, 825-5470 g). Only 71.3% to 72.6% of weight estimations were within 10% of actual BW using original published models by Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337) and INTERGROWTH-21st (Ultrasound Obstet Gynecol 2017; 49:478-486). All predictions were accurate by using sample-specific model coefficients to minimize bias in making these comparisons (Hadlock, 0.4% ± 8.7%; INTERGROWTH-21st, 0.5% ± 10.0%; AVol, 0.3% ± 7.4%; and TVol, 0.3% ± 8.0%). Both AVol- and TVol-based models improved the percentage of correctly classified BW ±10% in 83.2% and 83.9% of cases, respectively, compared to the INTERGROWTH-21st model (73.8%; P < .01). For BW of less than 2500 g, all models slightly overestimated BW (+2.0% to +3.1%). For BW of greater than 4000 g, AVol (-2.4% ± 6.5%) and TVol (-2.3% ± 6.9%) models) had weight predictions with small systematic errors that were not different from zero (P > .05). For these larger fetuses, both AVol and TVol models correctly classified BW (±10%) in 83.3% and 87.5% of cases compared to the others (Hadlock, 79.2%; INTERGROWTH-21st, 70.8%) although these differences did not reach statistical significance. CONCLUSIONS: In this cohort, the inclusion of automated FLV measurements with conventional 2-dimensional biometry was generally associated with improved weight predictions.

Longitudinal Course of Short-Term Variation and Doppler Parameters in Early Onset Growth Restricted Fetuses.

PURPOSE: To evaluate the longitudinal pattern of fetal heart rate short term variation (STV) and Doppler indices and their correlation to each other in severe growth restricted (IUGR) fetuses. MATERIALS AND METHODS: In this retrospective study, pregnancies with a birth weight below the 10th percentile, born between 24 and 34 gestational weeks with serial Doppler measurements in combination with a computerized CTG (cCTG) with calculated STV were included. Longitudinal changes of both Doppler indices and STV values were evaluated with generalized additive models, adjusted for gestational age and the individual. For all measurements the frequency of abnormal values with regard to the time interval before delivery and Pearson correlations between Doppler indices and STV values were calculated. RESULTS: 41 fetuses with a total of 1413 observations were included. Over the course of the whole study period, regression analyses showed no significant change of STV values (p = 0.38). Only on the day of delivery, a prominent decrease was observed (mean STV d28-22: 7.97 vs. mean STV on day 0: 6.8). Doppler indices of UA and MCA showed a continuous, significant deterioration starting about three weeks prior to delivery (p = 0.007; UA and p < 0.001, MCA). Correlation between any Doppler index and STV values was poor. CONCLUSION: Fetal heart rate STV does not deteriorate continuously. Therefore, cCTG monitoring should be performed at least daily in these high-risk fetuses. Doppler indices of umbilical artery (UA) and middle cerebral artery (MCA), however, showed continuous deterioration starting about 3 weeks prior to delivery.

Ultrasound Fetal Weight Estimation in Diabetic Pregnancies.

OBJECTIVES: To evaluate different formulas for estimating fetal weight in diabetic pregnancies. METHODS: This retrospective study evaluated the precision of ultrasound fetal weight estimation in 756 pregnancies complicated by gestational diabetes between 2002 and 2016. The estimated fetal weights (EFWs) were obtained within 7 days of delivery from 10 weight estimation formulas and were compared with pair-wise matched controls from 15,701 patients. The precision of the evaluated formulas for EFW was analyzed by median absolute percentage errors (MAPEs), mean percentage errors (MPEs), and proportions of estimates within 10% of actual birth weight. RESULTS: Among the tested formulas, the lowest MAPE was detected with formula I of Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337), and the formula of Schild et al (Ultrasound Obstet Gynecol 2004; 23:30-35) had the highest proportion of estimates within the 10% range. The EFW in diabetic patients showed a slight trend toward overestimation in comparison with the matched controls (MPE estimates showed a trend toward more positive values). In most of the EFW formulas that were evaluated, no significant differences were detected in MAPEs and estimates within the 10% range. The MPE estimates with most formulas in both groups were close to zero. Overall, the differences between most of the evaluated formulas were small. CONCLUSIONS: Little evidence was found for differences in the accuracy of the EFW in diabetic pregnancies and controls. The Hadlock I formula showed the lowest MAPE, and the Schild formula had the highest proportion of estimates within the 10% range.

Correlation of short-term variation and Doppler parameters with adverse perinatal outcome in small-for-gestational age fetuses at term.

OBJECTIVE: To evaluate the association of short-term variation (STV) and Doppler parameters with adverse perinatal outcome in small-for-gestational-age (SGA) fetuses at term. METHODS: In this retrospective single-center study 97 patients with singleton SGA fetuses at term (≥ 37 + 0 weeks' gestation) were examined. Inclusion criteria were a birth weight < 10th centile, cephalic presentation and planned vaginal birth. Only cases with available Doppler measurements of umbilical artery (UA) and middle cerebral artery (MCA) with calculated cerebroplacental ratio (CPR) in combination with a computerized CTG (cCTG) and STV 72 h prior to delivery were eligible for analysis. Pulsatility indices (PI) were converted into multiples of median (MoM), adjusted for gestational age. The association between Doppler indices and STV values with mode of delivery [secondary cesarean delivery (CD), operative vaginal delivery (OVD), as well as secondary CD and OVD due to fetal distress] and neonatal outcome [UA blood pH ≤ 7.15 and the need of admission to the neonatal intensive care unit (NICU)] was analyzed using logistic regression analysis. RESULTS: There was a significant association between UA PI MoM and the rate of CD. CD due to fetal distress, OVD and OVD due to fetal distress did not show a correlation with the evaluated Doppler parameters. Furthermore, we did not find an association between low UA birth pH and Doppler parameters while neonates with the need of admission to NICU had significant higher UA PI MoM and significant lower MCA PI MoM and CPR MoM. Regarding STV, a significant effect of low STV on NICU admission was found while none of the other assessed outcome parameters were significantly associated with STV. CONCLUSION: STV and Doppler parameters in SGA fetuses at term are significantly associated to the rate of NICU admission.

Can Sonographic Fetal Biometry Predict Adverse Perinatal Outcome?

OBJECTIVE: To evaluate the association of sonographic fetal biometry (sonographic head circumference (soHC), sonographic abdominal circumference (soAC), estimated fetal weight (EFW)) with mode of delivery and adverse perinatal outcome. METHODS: Singleton pregnancies with a gestational age ≥ 37 weeks and an ultrasound examination with complete biometric parameters within 7 days before delivery were retrospectively included. The association between soHC, soAC, EFW and fetal (5-min Apgar < 7, pH < 7.1, neonatal intensive care unit (NICU) admission, shoulder dystocia (ShD)) and maternal (obstetric intervention (OI): caesarean or vaginal operative delivery, obstetric anal sphincter injury syndrome (OASIS), postpartum hemorrhage (pph)) adverse outcomes were analyzed using univariate and multivariate logistic regression analyses. RESULTS: 12 396 women were included and 3479 (28.07 %) needed an OI. Multivariate analyses demonstrated significant contributions for the prediction of OI by soHC and soAC, whereas EFW did not reach significance. The highest OR was shown for soHC (1087, p < 0.001). ShD occurred in 73 (0.59 %) of the deliveries. Multivariate analyses showed that significant contributions for the prediction of ShD were provided only by soAC (OR 1460, p = 0.007). For the other maternal and neonatal adverse outcome parameters, no significant association with the biometric measurements could be demonstrated in the multivariate analyses. The overall detection rates for the prediction of adverse perinatal outcome by the different biometric parameters and EFW were poor. CONCLUSION: Obstetric management decisions should not be based solely on measurements of biometric parameters or EFW.

Correlation of short-term variation and Doppler parameters with adverse perinatal outcome in low-risk fetuses at term.

OBJECTIVE: To evaluate the association of short-term variation (STV) and Doppler parameters with adverse perinatal outcome in low-risk fetuses at term. METHODS: This was a retrospective study of 1008 appropriate-for-gestational age (AGA) term fetuses. Doppler measurements [umbilical artery (UA), middle cerebral artery (MCA), and cerebroplacental ratio (CPR)] and computerized CTG (cCTG) with STV analysis were performed prior to active labor (≤ 4 cm cervical dilatation) within 72 h of delivery. The association between Doppler indices and STV values with adverse perinatal outcome was analyzed using univariate regression analysis. RESULTS: No significant association between Doppler parameters and the need for secondary cesarean delivery (CD) or operative vaginal delivery (OVD) was shown. Regarding fetuses delivered by CD due to fetal distress, regression analyzes revealed significantly higher UA PI MoM. However, the differences in MCA PI MoM and CPR MoM were not statistically significant. Fetuses with the need for emergency CD showed significantly higher UA PI MoM, lower MCA PI MoM and lower CPR MoM. Neonates with a 5-min Apgar score < 7 had significantly lower MCA PI MoM and neonatal acidosis (UA pH ≤ 7.10) showed a significant association with UA PI MoM. None of the assessed outcome parameters were significantly associated to STV. CONCLUSION: Doppler indices assessed close to delivery in low-risk fetuses at term show a moderate association with adverse outcome parameters, whereas STV does not appear to predict poor perinatal outcome in this group of fetuses.

Piepkorn type of osteochondrodysplasia: Defining the severe end of FLNB-related skeletal disorders in three fetuses and a 106-year-old exhibit.

The Piepkorn type of lethal osteochondrodysplasia (POCD) is a rare and lethal dwarfing condition. Four cases have been reported to date. The characteristic features are distinctly shortened "flipper-like" limbs, polysyndactyly, excessive underossification, especially of the limb bones and vertebrae, and large (giant) chondrocytes in the cartilaginous bone primordia. These characteristics allowed the diagnosis of Piepkorn type of osteochondrodysplasia in four new cases, three fetuses of 15 to 22 weeks and one 106-year-old museum exhibit. Piepkorn type of osteochondrodysplasia has been assigned to the giant cell chondrodysplasias such as atelosteogenesis type 1 (AO1) and boomerang dysplasia (BD). Analysis of the Filamin B gene in 3p14.3, which is associated with these disorders, allowed the identification of the first FLNB mutations in Piepkorn type of osteochondrodysplasia. The heterozygous missense mutations, found in the three fetuses, were located in exons 28 and 29, encoding the immunoglobulin-like repeat region R15, one of three mutational hot spots in dominant FLNB-related skeletal disorders. Direct preparations and alcian blue staining revealed single upper and lower arm and leg bone primordia, preaxial oligodactyly, and polysyndactyly with complete fusion and doubling of the middle and end phalanges II-V to produce eight distal finger rays. Considering the unique clinical features and the extent of underossification, Piepkorn type of osteochondrodysplasia can be regarded as a distinct entity within the AO1-BD-POCD continuum.

Intrauterine Growth Restriction (IUGR) Induces Signs of Subclinical Atherosclerosis in 6-Year-Old Infants Despite Absence Of Excessive Growth.

Background Postnatal catch-up growth and rapid weight gain after intrauterine growth restriction (IUGR) seem to increase the risk for later disease. This study aimed to compare features of the metabolic syndrome early in life between IUGR and appropriate for gestational age (AGA) infants. Patients Data for 9 infants with IUGR defined by a birth weight<10th percentile and ultrasound-proven placental insufficiency and 11 AGA children were available. Method Postnatal growth, auxological, cardiovascular, and metabolic parameters up to a chronological age of 6 years were assessed: Fasting serum concentrations of LDL-cholesterol, insulin, leptin, IGF-I, DHEAS, skinfold thicknesses, blood pressure, and mean carotid intima-media thickness (cIMT). Results All IUGR infants showed catch-up growth, although mean BMI SDS and total subcutaneous fat mass at the age of 6 years were still slightly lower compared to the AGA cohort. Reduced serum leptin concentrations were observed in IUGR infants (p=0.02), whereas no significant difference was found for IGF-I, insulin, LDL-cholesterol and DHEAS concentrations. Mean cIMT was significantly higher in IUGR infants (p<0.05). Mean arterial pressure did no differ. Discussion and Conclusion In 6-year-old IUGR infants with catch-up growth, who still had a slightly reduced BMI SDS compared to the AGA group, signs of subclinical atherosclerosis were detectable suggesting that cardiovascular risk in IUGR may be present even in the absence of excessive growth.

Longitudinal z Score Distribution in Sonographic Fetal Biometry: Influence of Examiner and Experience.

OBJECTIVES: To analyze the influence of examiners and their experience on the quality of biometric measurements via the evolution of z scores in a longitudinal multicenter study. METHODS: This retrospective study included 4607 sonographic fetal biometric examinations performed by 18 examiners at the beginning of their sonography training. To analyze the quality of biometric measurements, z scores comparing the individual measurements with the expected values from a standard population were computed. To investigate the effect of examiners and their experience, we applied a multivariable regression analysis via generalized additive mixed models. RESULTS: Mean z scores for biparietal diameter, abdominal circumference, and femur length were statistically different from the expected value of 0 (P < .001); no significant differences were found for head circumference measurements. Regression analyses showed a significant effect of the number of examinations on the distribution of z scores for each type of measurement. This effect yielded z score values close to the expected value of 0 at 100 to 200 examinations for all biometric measurements, indicating good consistency with the distribution of values in the reference population. Near the end of the study period, an increasing tendency toward either overestimation (head circumference) or underestimation (biparietal diameter, abdominal circumference, and femur length) was observed. CONCLUSIONS: A longitudinal analysis of the z score distribution for quality control of biometry is feasible. A prospective and automatized use of this technique could help identify potential systematic errors and therefore improve the detection rate for high-risk pregnancies.