The effect of delayed umbilical cord clamping on cord blood gas analysis in vaginal and caesarean-delivered term newborns without fetal distress: a prospective observational study

OBJECTIVE

To determine variations in cord blood gas (CBG) parameters after 3-minute delayed cord clamping (DCC) in vaginal deliveries (VDs) and caesarean deliveries (CDs) at term without fetal distress.

DESIGN

Prospective observational study.

SETTING

University hospital.

SAMPLE

CBG from 97 VDs and 124 CDs without fetal distress.

METHODS

Comparison of paired arterial-venous CBG parameters drawn at birth from the unclamped cord and after 3-minutes DCC for VDs and CDs.

MAIN OUTCOME MEASURES

Base excess, bicarbonate, haematocrit and haemoglobin from both arterial and venous cord blood, lactate, neonatal outcomes, partial pressure of oxygen (pO₂ ), partial pressure of carbon dioxide (pCO₂ ), pH, and postpartum haemorrhage.

RESULTS

Arterial cord blood pH, bicarbonate ( HCO 3 - , mmol/l), and base excess (BE, mmol/l) decreased significantly after 3-minute DCC both in VDs (pH = 7.23 versus 7.27; P < 0.001; HCO 3 -  = 23.3 versus 24.3; P = 0.004; BE = -5.1 versus -2.9; P < 0.001) and CDs (pH = 7.28 versus 7.34; P < 0.001; HCO 3 -  = 26.2 versus 27.2; P < 0.001; BE = -1.5 versus 0.7; P < 0.001). After 3-minute DCC, pCO₂ increased in CDs only (57 versus 51; P < 0.001), whereas lactate increased more in CDs compared with VDs (lactate, +1.1 [0.9, 1.45] versus +0.5 [-0.65, 2.35]; P = 0.01). Postpartum maternal haemorrhage, neonatal maximum bilirubin concentration, and need for phototherapy were similar between the two groups. Newborns born by CD more frequently required postnatal clinical monitoring or admission to a neonatal intensive care unit.

CONCLUSIONS

After 3-minute DCC, the acid-base status shifted towards mixed acidosis in CDs and prevalent metabolic acidosis in VDs. CDs were associated with a more pronounced increase in arterial lactate, compared with VDs.

TWEETABLE ABSTRACT

By 3-minute DCC, acid-base status shifts towards mixed and metabolic acidosis in caesarean and vaginal delivery, respectively.

High-dose sequential chemotherapy (HDSC) with peripheral blood progenitor cells (PBPC) support for high-risk breast cancer (BC)

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Background: Recent reports suggest that intensified adjuvant chemotherapy with stem cell support improve disease free (DFS) and overall survival (OS) in subgroups of patients with high risk BC. We retrospectively analyzed the efficacy, safety and feasibility of a program of HDSC with PBPC support (according to the Milan protocol, ASCO 2001) in patients with BC at high risk of recurrence Methods: Between February 1995 and January 2001, 201 non-consecutive patients with more than 3 positive axillary nodes at surgery, median age 46 (range 27–62), has been evaluated. Median number of involved nodes was 15 (range 3–48), 38% and 49% pts had ER and PgR negative tumors, respectively. Fourty-sevent percent of pts had tumors with a high proliferative activity. HDSC consisted of sequential administration of cyclosphosphamide 7 g/m2 (day 0) plus filgrastim 5 μg/kg s.c. daily and stem cell collection, methotrexate 8 g/m2 plus vincristine 2 mg/m2 (day +16), and two consecutive courses of epidoxorubicin 120 mg/m2 (days +23 and + 38) plus filgrastim 5 μg/kg s.c. daily. Myeloablative therapy (day +58) consisted of thiotepa 600 mg/m2 and melphalan 160 mg/m2 plus PBPCs and filgrastim 5 μg/kg s.c. daily. Results: Three pts discontinued the program permanently because of toxicity. A median of 9,35x106/kg (range 3.35–35.62) CD34+ cells was infused. Engraftment for neutrophils (> 500/μl) and platelets (> 20.000/μl) was observed a median of 9 days (range 7–17) and 10 days (range 7–18) after PBPC infusion, respectively. No treatment-related deaths were recorded. After a median follow-up of 79 months, 108 (54%) pts are disease- free. Ninety-three patients experienced disease recurrence [9/93 (10%) pts had loco regional disease recurrence and 84/93 (90%) pts distant recurrence], of whom 58/93 (63%) have died. Five-year DFS and OS from the start of treatment are 55% and 71%, respectively. No poor marrow function, myelodysplastic syndrome or secondary tumors were observed. In 2-sided log-rank tests, hormone-receptor status and the number of tumor-positive axillary lymph nodes were significant prognostic factors for DFS. Conclusions: Our results confirm that HDSC is a safe procedure and is associated with favorable outcome in patients with high-risk BC.

No significant financial relationships to disclose.

Relationship between plasma fatty acid profile and antioxidant vitamins during normal pregnancy

OBJECTIVE

To study the changes of plasma fatty acids and lipophilic vitamins during normal pregnancy.

DESIGN

Plasma fatty acid profile and the concentration of carotenoids, tocopherols and retinol were measured in healthy women at the first and third trimesters of pregnancy, at delivery, and in cord blood plasma.

RESULTS

Maternal plasma cholesterol and triglycerides increased from the first to the third trimester of gestation, while free fatty acids progressively increased from the first trimester through the third trimester to delivery, suggesting an enhanced lipolytic activity. Plasma levels of alpha- and gamma-tocopherols, lycopene and beta-carotene also progressively increased with gestation, but values in cord blood plasma were lower than in mothers at delivery. Retinol levels declined with gestational time and values in cord blood plasma were even lower. The proportion of total saturated fatty acids increased with gestation, and it further increased in cord blood plasma. Total n-9 fatty acids remained stable throughout pregnancy, and slightly declined in cord blood plasma, the change mainly corresponding to oleic acid. Total n-6 fatty acids declined with gestation and further decreased in cord blood plasma, and a similar trend was found for linoleic acid. However, arachidonic acid declined in women at the third trimester and at delivery as compared to the first trimester, but was enhanced in cord blood plasma. The proportion of total n-3 fatty acids remained stable throughout pregnancy at the expense of decreased alpha-linolenic acid at delivery but enhanced eicosapentaenoic acid, with small changes in docosahexaenoic acid. The proportion of these n-3 fatty acids was similar in cord blood plasma and maternal plasma at delivery.

CONCLUSIONS

Owing to the different placental transfer mechanisms and fetal capability to metabolize some of the transferred fatty acids and lipophilic vitamins, the fetus preserves the essential compounds to assure their appropriate availability to sustain its normal development and to protect itself from the oxidative stress of extrauterine life.

SPONSORSHIP

The studies reported herein have been carried out with financial support from the Commission of the European Communities, specific RTD programme 'Quality of Life and Management of Living Resources', QLK1-2001-00138 'Influence of Dietary Fatty Acids on the Pathophysiology of Intrauterine Foetal Growth and Neonatal Development' (PeriLip). It does not necessarily reflect its views and in no way anticipates the Commission's future policy in this area.

The endocrine and metabolic profile of the growth-retarded fetus

Intrauterine growth retardation (IUGR) is characterized by the failure of the fetus to grow at a normal rate in utero and is associated with a number of endocrine and metabolic changes. Our knowledge of the placental nutrient supply and the endocrine status of the fetal-placental unit during pregnancies involving IUGR has greatly increased over the past decade as a result of the availability of fetal blood samples obtained under relatively steady state conditions. These studies have provided evidence that the supply of glucose is impaired only under severe conditions, whereas placental transfer of amino acids is reduced even in fetuses with normal oxygenation and feto-placental blood flow. Moreover, significant in utero relationships have been reported between fetal weight and circulating levels of growth factors such as insulin-like growth factor-I and leptin. When measured per kg fetal weight, however, levels of leptin are significantly higher in growth-retarded fetuses, with abnormal feto-placental blood flow and reduced oxygen content. The metabolic and endocrine changes observed should be interpreted in relation to the severity of the disease.

Umbilical vein blood flow in growth-restricted fetuses

OBJECTIVE

To determine whether umbilical blood flow is reduced in a subset of growth-restricted (IUGR) fetuses when expressed as flow per kilogram or flow per unit of specific sonographic fetal measurements.

DESIGN

Prospective.

SUBJECTS

Thirty-seven IUGR fetuses were examined by Doppler ultrasound within 4 h of the last non-stress test prior to delivery. This population was divided into three groups of varying clinical severity according to the characteristics of umbilical arterial pulsatility index (PI) and heart rate.

METHODS

Absolute and weight-specific umbilical vein (UV) flow were calculated from measurements of UV diameter and UV mean velocity. Umbilical vein diameter, velocity and UV flow were calculated also per unit head (HC) or abdominal circumference (AC) and correlated with gestational age.

RESULTS

Umbilical vein flow (UVf) per kilogram fetal weight was significantly lower in the more severe IUGR fetuses (abnormal umbilical arterial PI) than in normally grown comparable fetuses (P < 0.001). Umbilical vein flow per unit HC was significantly lower in the three groups (P < 0.001) than in the control population. The UV diameter/HC ratio was normal whereas UV velocity/HC ratio was significantly lower in IUGR fetuses than in comparable controls.

CONCLUSIONS

The present study clearly establishes that umbilical venous blood flow is reduced in IUGR fetuses on a weight-specific basis. The sonographic growth parameter which best distinguishes umbilical flow differences of IUGR fetuses from normal fetuses is the head circumference.

An embryonic demethylation mechanism involving binding of transcription factors to replicating DNA

In vertebrates, transcriptionally active promoters are undermethylated. Since the transcription factor Sp1, and more recently NF-kappaB, have been implicated in the demethylation process, we examined the effect of transcription factors on demethylation by injecting in vitro methylated plasmid DNA into Xenopus fertilized eggs. We found that various transactivation domains, including a strong acidic activation domain from the viral protein VP16, can enhance demethylation of a promoter region when fused to a DNA binding domain which recognizes the promoter. Furthermore, demethylation occurs only after the midblastula transition, when the general transcription machinery of the host embryo becomes available. Nevertheless, transcription factor binding need not be followed by actual transcription, since demethylation is not blocked by alpha-amanitin treatment. Finally, replication of the target DNA is a prerequisite for efficient demethylation since only plasmids that carry the bovine papilloma virus sequences which support plasmid replication after the midblastula transition are demethylated. No demethylation is detectable in the oocyte system where DNA is not replicated. These results suggest that, in the Xenopus embryo, promoters for which transcription factors are available are demethylated by a replication-dependent, possibly passive mechanism.

[Effect of the type of swab on the isolation of Chlamydia trachomatis]

The success in the isolation of C. trachomatis is dependent on several factors. One of them is the type of swab used for collection the specimens. As some types of swabs, such as calcium alginate and aluminum, cotton and wood have recently been shown to decrease the isolation rate, different types of swabs were prepared and tested in our laboratory. Commercial aluminum, type 5056 aluminum and stainless steel were used with the same type of cotton. Commercial swabs of cotton and wood were tested too. The swabs were incubated with 1 ml of transport medium and a known number of UFI for 24 h at 4 degrees C, then were processed for isolation. The isolation rate with commercial aluminum was 95%, with aluminum 5056 was 91% and with stainless steel was 98%. The swabs made of cotton and wood were toxic to McCoy cells, destroyed the monolayer and did not allow the recovery of C. trachomatis. The poor recovery of Chlamydia from some types of swab, indicates that the available swabs used in each laboratory should be periodically evaluated to avoid false negative results.

[Isolation of Chlamydia trachomatis in populations with different risks of infection]

The level of infection by Chlamydia trachomatis in patients attending different units of urogenital diseases was evaluated. One hundred and fifty four patients divided in four groups were studied. Fifty percent of C. trachomatis isolation was achieved in the high risk group A, composed by men attending to a sexual transmission disease service. Among men attending an urology unit (group B) isolation reached 20.7%. In group C composed by women from a general gynecological unit the rate of isolation was 13.3%; and in group D (men and women with infertility problems) the rate of isolation was 4.3%. These isolation values were achieved combining the primoinoculation of cell cultures with a posterior blind passage. The known risk factors such as the number of sexual partners, age and previous data of sexually transmitted diseases affected the percentages of C. trachomatis isolation from each group.