Blood gas values in clamped and unclamped umbilical cord at birth

Tommaso, Mariarosaria Di; Seravalli, Viola; Martini, Irene; Torre, Pasquale La; Dani, Carlo

doi:10.1016/j.earlhumdev.2014.03.010

Cited by 20 publications

(18 citation statements)

References 21 publications

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“…It is a low resistance vascular bed, which promotes the fetalto-maternal exchange of deoxygenated blood under low pressure [3,50]. Despite the low partial pressure of oxygen in the placenta, oxygen delivery to fetal tissues remains adequate due to the combined high ventricular output and the presence of fetal hemoglobin, which has a higher oxygen affinity than adult hemoglobin [50,55,56].…”

Section: Fetal Structural Adaptations: the Four Shunts In Fetal Circumentioning

confidence: 99%

The Transitional Heart: From Early Embryonic and Fetal Development to Neonatal Life

Tan

Lewandowski²

2019

Fetal Diagn Ther

176

123

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Formation of the human heart involves complex biological signals, interactions, specification of myocardial progenitor cells, and heart tube looping. To facilitate survival in the hypoxemic intrauterine environment, the fetus possesses structural, physiological, and functional cardiovascular adaptations that are fundamentally different from the neonate. At birth, upon separation from the placental circulation, the neonatal cardiovascular system takes over responsibility of vital processes for survival. The transition from the fetal to neonatal circulation is considered to be a period of intricate physiological, anatomical, and biochemical changes in the cardiovascular system. With a successful cardiopulmonary transition to the extrauterine environment, the fetal shunts are functionally modified or eliminated, enabling independent life. Investigations using medical imaging tools such as ultrasound and magnetic resonance imaging have helped to define normal and abnormal patterns of cardiac remodeling both in utero and ex utero. This has not only allowed for a better understanding of how congenital cardiac malforma-tions alter the hemodynamic transition to the extrauterine environment but also how other more common complications during pregnancy including intrauterine growth restriction, preeclampsia, and preterm delivery adversely affect offspring cardiac remodeling during this early transitional period. This review article describes key cardiac progenitors involved in embryonic heart development; the cellular, physiological, and anatomical changes during the transition from fetal to neonatal circulation; as well as the unique impact that different pregnancy complications have on cardiac remodeling.

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Section: Fetal Structural Adaptations: the Four Shunts In Fetal Circumentioning

confidence: 99%

The Transitional Heart: From Early Embryonic and Fetal Development to Neonatal Life

Tan

Lewandowski²

2019

Fetal Diagn Ther

176

123

View full text Add to dashboard Cite

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Section: Is Pulsating Cord Blood Sampling a Suitable And Reliable Metmentioning

confidence: 74%

“…We reached the same conclusion in 2014, when we performed a prospective observational study on 46 matched pairs of umbilical artery and vein blood samples from the same cord, unclamped and clamped, respectively. 5 We observed that there were no significant differences on arterial pH, PO 2 , pCO 2 , SaO 2 or hemoglobin concentration (ctHb) between the samples obtained within 90 seconds from birth and the clamped one, analyzed immediately after the previous sampling. Conversely, the venous SaO 2 , ctHb, and BE were significantly different between unclamped and clamped cord, although pH, PO 2 , and pCO 2 were comparable.According to this evidence, we validated for the first time the reliability of pulsating cord blood sampling compared with the standard clamped technique, and we proposed a modified method for blood sampling from the unclamped pulsating cord, allowing the sampling of the umbilical arterial vessels as well as the DCC, essential for placental transfusion.…”

mentioning

confidence: 74%

Is pulsating cord blood sampling a suitable and reliable method for cord gas analysis at birth?

Tommaso

Vannuccini

2018

Acta Obstet Gynecol Scand

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Is pulsating cord blood sampling a suitable and reliable method for cord gas analysis at birth?Sir,We read with interest the Commentary "Delayed cord clamping and cord gas analysis at birth" by Xodo et al 1 that easily provides the clinicians the physiological basis and the rationale for umbilical cord blood gas analysis, exploring the effect of delayed cord clamping (DCC), sampling, and analysis.The final remark, considering available evidence, 2-4 is to obtain umbilical cord blood for gas analysis from both the umbilical artery and umbilical vein from the pulsating cord immediately after birth and during DCC. We reached the same conclusion in 2014, when we performed a prospective observational study on 46 matched pairs of umbilical artery and vein blood samples from the same cord, unclamped and clamped, respectively. 5 We observed that there were no significant differences on arterial pH, PO 2 , pCO 2 , SaO 2 or hemoglobin concentration (ctHb) between the samples obtained within 90 seconds from birth and the clamped one, analyzed immediately after the previous sampling. Conversely, the venous SaO 2 , ctHb, and BE were significantly different between unclamped and clamped cord, although pH, PO 2 , and pCO 2 were comparable.According to this evidence, we validated for the first time the reliability of pulsating cord blood sampling compared with the standard clamped technique, and we proposed a modified method for blood sampling from the unclamped pulsating cord, allowing the sampling of the umbilical arterial vessels as well as the DCC, essential for placental transfusion. Xodo et al suggest obtaining the samples from unclamped cord as quickly as possible, first from the artery and then from the vein. This procedure should be performed by trained personnel in a short amount of time, in order to reduce the difference among measured values of cord blood acid-base parameters. 2 In our study the comparison between simultaneous cord gas values from unclamped and clamped cord within 90 seconds from delivery did not show relevant differences in arterial samples. 5 Umbilical arterial blood most accurately reflects fetal oxygenation and acid-base status, whereas the umbilical vein blood gas measurements better reflect maternal status and placental function. The clinician performing gas analysis should be aware that sampling from arterial unclamped cord guarantees a good reliability of results compared with the standard technique. At the same time, this procedure entails all the benefits for the fetus due to DCC, as it allows placental transfusion to the infant. 5 O RCI D Mariarosaria Di Tommaso

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“…Different blood sampling procedures were practiced at vaginal delivery at our two maternity units: in Lund the cord vessels were routinely punctured promptly after birth by an assistant nurse without clamping the cord, whereas in Malmö the cord was double‐clamped by the midwife and blood collected later. The clamping or not clamping procedures make no difference per se in blood gas values as long as the samples are taken promptly, but for a busy midwife the clamping might be delayed. The technique used in Lund then resulted in a better quality of samples, with an additional bonus of allowing more blood to stream from the placenta to the newborn.…”

Section: Discussionmentioning

confidence: 99%

Arterio‐venous blood gas Δvalues for validation of umbilical cord blood samples at birth are not only biased by sample mix ups but also affected by clinical factors

Mokarami

Wiberg

Källén

et al. 2018

Acta Obstet Gynecol Scand

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Introduction Traditional validation of umbilical cord blood samples with positive veno‐arterial ΔpH and arterio‐venous ΔpCO2 values confirms the source of samples, whereas negative Δvalues represent mix‐up of samples. To investigate whether this is true, the distributions of V‐A ΔpO2 and A‐V Δlactate were also explored and related to clinical characteristics. In addition, different cord blood sampling techniques were evaluated. Material and methods Register study with cord blood acid‐base and clinical data from 27 233 newborns. Clinical characteristics were related to positive, zero and negative Δvalues. Blood samplings from unclamped and double‐clamped cords were compared. A two‐sided P < 0.05 was considered significant. Results ΔpH and ΔpCO2 values distributed into positive, around zero, and negative sub‐populations, with significant differences in pH and clinical characteristics between sub‐populations. No such sub‐populations were distinguished for ΔpO2 and Δlactate. The 2.5th and 5th ΔpH percentiles were 0.013 and 0.022, respectively, and for ΔpCO2 0.30 and 0.53 kPa. Applying 5th percentile criteria resulted in 3.5% of “approved” cases showing a ΔpO2 ≤ 0. Puncture and sampling of the unclamped cord resulted in significantly better sample quality. Conclusions Unphysiological negative ΔpO2 values occurred despite correct validation with traditional criteria. Δlactate cannot be used for validation because both positive and negative values are physiological. Positive/around zero/negative ΔpH and ΔpCO2 sub‐populations were associated with significant differences in pH and clinical characteristics, indicating that defective sampling and sample handling are not the sole explanations for negative Δvalues. Prompt puncture and sampling of the unclamped cord resulted in best sample quality.

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Blood gas values in clamped and unclamped umbilical cord at birth

Cited by 20 publications

References 21 publications

The Transitional Heart: From Early Embryonic and Fetal Development to Neonatal Life

The Transitional Heart: From Early Embryonic and Fetal Development to Neonatal Life

Is pulsating cord blood sampling a suitable and reliable method for cord gas analysis at birth?

Arterio‐venous blood gas Δvalues for validation of umbilical cord blood samples at birth are not only biased by sample mix ups but also affected by clinical factors

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