Tilo Burkhardt

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

Abstract 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.

Antenatal betamethasone administration alters stress physiology in healthy neonates.

OBJECTIVE: To analyze hypothalamic-pituitary-adrenal axis balance in healthy newborns after antenatal betamethasone treatment for lung maturation where delivery could be prolonged until or near term. METHODS: In a prospective observational study, salivary cortisol and cortisone levels were measured at the fourth day of life during resting conditions and in response to a pain-induced stress event in 23 neonates with antenatal exposure to a single course of betamethasone (2×12 mg) and compared with 40 controls. The mean interval between betamethasone treatment and delivery was 60±23 days. RESULTS: On day 4 of life, neonates in the control group exhibited a significant increase in cortisol and cortisone from baseline levels after the stress induction (1.175–2.4 ng/mL for cortisol and 11.35–18.15 ng/mL for cortisone [both P<.05]), whereas, in betamethasone-exposed neonates, cortisol and cortisone stress response was not significantly different from baseline levels (1.39–1.6 ng/mL for cortisone [P=.76] and 14.8–17.1 ng/mL for cortisol [P=.69]). No influence of gestational age at betamethasone administration (P=.76) or gestational age at delivery (P=.71) on stress response patterns was observed in a multiple stepwise regression. CONCLUSION: A single course of antenatal betamethasone treatment induces a suppression of stress reactivity in healthy newborns. LEVEL OF EVIDENCE: II

Decreased Umbilical Artery Compliance and IGF-I Plasma Levels in Infants with Intrauterine Growth Restriction – Implications for Fetal Programming of Hypertension

Epidemiological studies link intrauterine growth restriction (IUGR) to arterial hypertension in adulthood. We compared umbilical arteries from IUGR (n=12, <5th weight percentile) vs. appropriate for gestational age (AGA) infants (n=12) using structural and functional analyses. The vessel wall area of umbilical arteries in the IUGR group was significantly smaller than in the AGA group (2.8 vs. 3.8mm(2), P<0.05). Myographic measurements showed that maximal tension [mN/mm] as well as maximal force [mN] were both significantly increased in IUGR arteries compared with AGA arteries (P<0.05). Serum levels of IGF-I, a regulator of elastin synthesis, were significantly lower in IUGR cord blood (P<0.01) than in AGA cord blood. These IGF-I serum levels correlated significantly with maximum tension in umbilical arteries (P<0.01). Low intrauterine IGF-I serum levels may account for thinner and stiffer umbilical arteries in IUGR infants in comparison to AGA infants thereby providing a potential link to arterial hypertension in adulthood.

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

Diagnostic accuracy of random massively parallel sequencing for non‐invasive prenatal detection of common autosomal aneuploidies: a collaborative study in Europe

The objective of this study is to validate the diagnostic accuracy of a non‐invasive prenatal test for detecting trisomies 13, 18, and 21 for a population in Germany and Switzerland.

Anemia—prevalence and risk factors in pregnancy

BACKGROUND To assess the prevalence of decreased iron stores and anemia in pregnant women. To determine whether the risk factors: socio-demographic background, age, BMI, and parity are associated with abnormal hemoglobin concentrations and/or abnormal iron status. METHODS A longitudinal study was carried out at the Department of Obstetrics, University Hospital of Zurich to establish the risk factors and prevalence of the decreased iron stores and anemia in early pregnancy. In order to determine the hematological parameters and ferritin levels, venous blood samples of 470 singleton pregnancies between 16 and 20 pregnancy weeks were collected. According to hemoglobin and iron status, the patients were divided into four groups: patients with iron deficiency anemia, patients with decreased iron stores, patients with anemia for other reasons and normal patients. The determinants socio-demographic background, age, BMI and parity were explored using multiple logistic regression analysis. RESULTS The prevalence of decreased iron stores (ferritin<20 μg/l) was observed in 31.8% of subjects (149/470) and anemia (Hb<110 g/l) in 18.5% (87/470). The prevalence of iron deficiency anemia was higher among women coming from former Yugoslavia and developing countries (p=0.004 and p=0.012). In patients coming from developing countries, a significant increase of anemia for other reasons was observed (p=0.027) and in patients older than 30 years, a significant increase of decreased iron stores (p=0.018). CONCLUSIONS In our study population with low parity, the prevalence of abnormal hemoglobin and abnormal iron status was 50.2% (236/470), and socio-demographic background was the most important risk factor of anemia.

Blunted stress response in small for gestational age neonates.

There is evidence that adverse conditions during intrauterine development affect future health of the offspring. Hypothalamus-pituitary-adrenal (HPA) axis dysregulation is assumed to play an important role in the association of small for gestational age (SGA) and the pathogenesis of hypertension and the metabolic syndrome. Stress response patterns in SGA neonates may identify a link with intrauterine-induced permanent maladaptation of the HPA axis. Salivary cortisol and cortisone levels were therefore analyzed during resting conditions and in response to a pain-induced stress event in SGA (<5th percentile) and appropriate for gestational age (AGA) neonates born ≥34 wk of gestation. In AGA neonates, salivary cortisol and cortisone levels significantly increased after the stress event (p < 0.05). In contrast, SGA infants exhibited a blunted steroid release after stress induction (p = 0.76, p = 0.65, respectively). No influence of mode of delivery (p = 0.93), gender (p = 0.21), and gestational age (p = 0.57) on stress response patterns was observed in a multiple stepwise regression. SGA neonates show a blunted physiologic activation of the HPA axis in response to a stress stimulus. Thus, intrauterine-induced alteration of HPA axis regulation seems to persist into the postnatal period and represents a prerequisite for the hypothesis of HPA axis involvement in the fetal origin of adult diseases.

Plasma Copeptin in Preterm Infants - a Highly Sensitive Marker of Fetal and Neonatal Stress

CONTEXT Copeptin is a stable by-product of arginine-vasopressin synthesis and reflects its secretion by the pituitary. OBJECTIVE The objective of the study was to investigate perinatal factors affecting copeptin concentrations in preterm infants at birth and at 3 d of life. DESIGN AND SETTING This was a prospective cross-sectional study at two Swiss university hospitals. PATIENTS One hundred sixty-seven preterm infants were enrolled, 59 infants born between 24 and 31 wk gestational age, 50 infants between 32 and 34 wk, and 58 between 35 and 36 wk. MAIN OUTCOME MEASURE Plasma copeptin concentrations, determined by a CT-proAVP-luminescence-immunoassay, were measured. RESULTS Copeptin at birth was significantly higher in preterm infants born vaginally [median (range) 366 (1-2900) pmol/liter, n = 43] than those born by cesarean section [6.9 (2-1580), n = 124]. In infants born after cesarean without prior labor (n = 66), estimated fetal weight less than the fifth percentile, suspect fetal heart rate, compromised placental perfusion, and chorioamnionitis were each associated with significantly elevated cord copeptin. Copeptin at 3 d of life was not associated with cord blood copeptin but inversely related to gestational age (Rs = -0.6, P < 0.001) and birth weight (Rs -0.612, P < 0.001). Day 3 copeptin increased alongside the level of mechanical respiratory support. CONCLUSION Copeptin is a highly sensitive marker of perinatal stress.

Continuous independent quality control for fetal ultrasound biometry provided by the cumulative summation technique

To apply the cumulative summation (CUSUM) technique for an evaluation of the learning process of sonographic fetal weight estimation at term in combination with the z‐scores of biometry determinants and to assess the time of appearance and sources of errors.

Sonographic prediction of macrosomia cannot be improved by combination with pregnancy-specific characteristics

To evaluate the predictive value of a combination of sonographic, clinical and demographic data for detecting fetal macrosomia compared to ultrasound fetal weight estimation alone.