Cord Arterial pH Research Articles

Asphyxie périnatale et infirmité motrice d’origine cérébrale (II – Implications médico-légales et prévention)

Obstetric litigation is a growing problem in developed countries and its escalating cost together with increasing medical insurance premiums is a major concern for maternity service providers, leading to obstetric practice cessation by many practitioners. Fifty-four to 74 % of claims are based on cardiotocographic (CTG) abnormalities and their interpretation followed by inappropriate or delayed reactions. A critical analysis is performed about the nine criteria identified by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics in their task force on Neonatal Encephalopathy and Cerebral Palsy: four essential criteria defining neonatal asphyxia and five other suggesting an acute intrapartum event sufficient to cause cerebral palsy in term newborns. The importance of placental histologic examination is emphasized in order to confirm sudden catastrophic events occurring before or during labor or to detect occult thrombotic processes affecting the fetal circulation, patterns of decreased placenta reserve and adaptative responses to chronic hypoxia. It may also exclude intrapartum hypoxia by revealing some histologic patterns typical of acute chorioamnionitis and fetal inflammatory response or compatible with metabolic diseases. Magnetic resonance imaging (MRI) of the infant's damaged brain is very contributive to elucidate the mechanism and timing of asphyxia in conjunction with the clinical picture, by locating cerebral injuries predominantly in white or grey matter. Intrapartum asphyxia is sometimes preventable by delivering weak fetuses by cesarean sections before birth, by avoiding some “sentinel” events, and essentially by responding appropriately to CTG anomalies and performing an efficient neonatal resuscitation. During litigation procedures, it is necessary to have access to a readable CTG, a well-documented partogram, a complete analysis of umbilical cord gases, a placental pathology and an extensive clinical work-up of the newborn infant including cerebral MRI. Malpractice litigation in obstetric care can be reduced by permanent CTG education, respect of national CTG guidelines, use of adjuncts such as fetal blood sampling for pH or lactates, regular review of adverse events in Clinical Risk Management (CRM) groups and periodic audits about low arterial cord pH in newborns, admission to neonatal unit, the need for assisted ventilation and the decision-to-delivery interval for emergency operative deliveries. Considering the fast occurrence of fetal cerebral hypoxic injuries, and thus despite an adequate management, many intrapartum asphyxias will not be preventable. Conversely, well-documented hypoxic-ischemic brain insults during the antenatal period do not automatically exclude intrapartum suboptimal obstetric care.

Outcome of severe intrapartum acidemia diagnosed with fetal scalp blood sampling

To analyze short-term neonatal outcome and the sampling to delivery interval in cases with severe intrapartum acidemia diagnosed with fetal scalp blood sampling (FBS). This is a secondary analysis of data from a trial of 2992 women, who were, when indicated, randomized to either lactate or pH analyses by FBS. Median and 95(th) centile values for lactate analyses were 2.9 mmol/L and 6.6 mmol/L, respectively. Corresponding pH values were 7.30 and 7.17. We defined severe intrapartum acidemia as lactate >6.6 mmol/L or pH <7.17. Outcome measures were cord artery pH <7.00, Apgar <7 at 5 min, hypoxic ischemic encephalopathy and time interval from FBS to delivery. Severe intrapartum acidemia was present in 85/1355 (6.3%) cases with lactate analyses and in 69/1008 (6.8%) cases with pH analyses. Cord artery pH <7.00 occurred in 12/154 (7.8%), Apgar <7 at 5 min in 16/154 (10.4%) and hypoxic ischemic encephalopathy in 4/154 (2.6%) of the cases. There were no differences in outcomes between the two groups. However, delivery was expedited more rapidly in the pH management group (median 16 vs. 21 min; P=0.01). Severe neonatal morbidity occurred in 10% or less in this high-risk group. FBS is an early marker of intrapartum hypoxia and can be used to prevent severe birth acidemia. Lactate might be an earlier marker than pH in the hypoxic process.

Head-to-body delivery interval and risk of fetal acidosis and hypoxic ischaemic encephalopathy in shoulder dystocia: a retrospective review

To examine the association between head-to-body delivery interval (HBDI) and cord arterial pH and base excess (BE), and the risk of development of hypoxic ischaemic encephalopathy (HIE). Retrospective review. A university hospital. Pregnancies complicated with shoulder dystocia during the period 1995-2009. Cases were identified from a search of the hospital electronic delivery records. Cord arterial pH and BE, and the incidence of HIE and perinatal death, were retrieved from medical records and correlated with HBDI, birth weight, mode of delivery and presence of nonreassuring fetal heart rate pattern and maternal diabetes using univariate analysis, followed by multivariate analysis. Any association between cord pH and HBDI. Of the 200 cases identified, the mean (standard deviation) HBDI was 2.5 minutes (1.5 minutes). Both HBDI and the presence of nonreassuring fetal heart rate pattern were independent factors for pH, and HBDI was the only significant factor for BE. Arterial pH dropped at a rate of 0.011 per minute [95% confidence interval (95% CI), 0.017-0.004; P = 0.002] with HBDI. The mode of delivery, birth weight and maternal diabetes did not affect blood gas levels. The respective risks of severe acidosis (pH < 7) and HIE with HBDI of <5 minutes were 0.5% and 0.5% versus 5.9% and 23.5% with HBDI ≥ 5 minutes. Cord arterial pH drops with HBDI during shoulder dystocia, but the risk of acidosis or HIE is very low with HBDI < 5 minutes.

Elective Induction Compared With Expectant Management in Nulliparous Women With a Favorable Cervix

A number of observational studies have demonstrated increased rates of cesarean delivery in nulliparous women, regardless of favorable or unfavorable cervical status. However, most used a design in which labor induction was compared with spontaneous labor at a given gestational age, not with expectant management, which is a more appropriate clinical comparison. A recent retrospective study demonstrated that nulliparous women who were electively induced had decreased rates of cesarean delivery in comparison to those who were expectantly managed. However, this study did not control for cervical status. In the present study, the investigators hypothesized that after controlling for cervical status, women who were electively induced would have a higher likelihood of cesarean delivery than those who were expectantly managed. A perinatal database was used to identify a population of singleton nulliparous women with a favorable cervix who underwent elective induction of labor (n = 294) or expectant management (n = 294) at 39 to 40 5/7 weeks of gestation, between 2006 and 2008. The elective induction and expectantly managed groups had similar demographic features except that the elective induction group had a slightly higher body mass index (29.4 ± 5.0 vs. 28.2 ± 3.6) and slightly higher Bishop's score (6.8 ± 1.6 vs. 5.8 ± 1.0). No significant differences were observed between the two groups in rates of cesarean delivery, the primary outcome (induction: 20.8% vs. expectant management: 20.1%; P = 0.84). The results remained stable following adjustment for potential confounding variables. Moreover, no significant differences were found for other maternal outcomes (operative vaginal delivery, chorioamnionitis, third- and fourth-degree lacerations, or postpartum hemorrhage), or neonatal outcomes (arterial cord pH less than 7.0, Apgar score less than 4 at 5 minutes, or admission to intensive care unit). The duration of labor and delivery was longer among women undergoing an elective labor induction (median: 12.7 hours) compared with those given expectant management (median: 9 hours; P < 0.001). These findings demonstrate that the likelihood of cesarean delivery among nulliparous women with a favorable cervix is similar for elective induction and expectant management.

Metformin should be considered in the treatment of gestational diabetes: a prospective randomised study

To examine if oral metformin is as effective as insulin in the prevention of fetal macrosomy in pregnancies complicated with gestational diabetes mellitus (GDM). Open-label prospective randomised controlled study. Maternity outpatient clinics in a secondary and tertiary level hospital in Finland. One hundred women with GDM who did not attain euglycaemia with diet. Women were randomised to therapy with insulin (n = 50) or oral metformin (n = 50). Incidence of large-for-gestational-age (LGA) infants and neonatal morbidity. There were no statistically significant differences in the incidence of LGA (8.5 versus 10.0%, P = 0.97), mean birthweight, mean cord artery pH or neonatal morbidity between the insulin and metformin groups. Fifteen (31.9%) of the 47 women randomised to metformin needed supplemental insulin. They were more obese (with a body mass index of 36 versus 30 kg/m(2), P = 0.002), had higher fasting blood glucose levels in an oral glucose tolerance test (6.1 versus 5.0 mmol/l, P = 0.001) and needed medical treatment for GDM earlier (26 versus 31 gestational weeks, P = 0.002) than women who were normoglycemic with metformin. There was a tendency to a higher rate of caesarean sections in the metformin group than in the insulin group (RR 1.9; 95% CI 0.99-3.71). Metformin seems to be suitable for the prevention of fetal macrosomy, especially in lean or moderately overweight women developing GDM in late gestation. Women with considerable obesity, high fasting blood glucose and an early need for pharmacological treatment may be more suitable for insulin therapy.

PP-99. Relationship between oxygen saturation and umbilical cord pH immediately after birth

Background: The aim of this study is to determine the relationship between oxygen saturation (SpO2) by pulse oximetry levels and umbilical cord arterial pH values in healthy newborns during the first 15 minutes of life. Methods: The study was performed with healthy term, appropriate-for-gestational-age newborn infants. The infants were divided in two groups: umbilical cord arterial blood pH value �7.19 (group 1)and>7.19(group2);SpO2levelsduringthefirst15minutesoflifewerecomparedbetweengroups.

Relation between umbilical cord blood pH, base deficit, lactate, 5‐minute Apgar score and development of hypoxic ischemic encephalopathy

Umbilical cord acid-base analysis is fundamental for assessing intrapartum hypoxia. The accuracy of arterial umbilical cord blood lactate, pH and base deficit to reflect a low 5-minute Apgar score and hypoxic ischemic encephalopathy (HIE) stage 2-3 was assessed, and new gestational age-adjusted reference standards were compared with traditional stationary reference values. A total of 13,735 pH-validated routine cord acid-base values from singleton deliveries were tested with stationary and gestational age-adjusted reference values using receiver operating characteristic curves and calculation of area under curve. University hospital. Accuracy of low pH, high base deficit and high lactate, alone or in combination, to imply 5-minute Apgar score < 7 or < 4 or HIE. Gestational age-adjusted values were for all parameters significantly better than crude values to indicate Apgar score < 7. For Apgar score < 4, the differences were not significant. The frequency of HIE was 0.046%, making statistical analyses pointless. Gestational age-adjusted lactate had the overall best accuracy and among combinations; a low age-adjusted pH plus high age-adjusted lactate was slightly better than a low age-adjusted pH plus high age-adjusted base deficit. The sensitivity and positive predictive value were low for all parameters. Lactate in cord arterial blood at birth is at least as good as base deficit to reflect an impaired condition at birth, and best when gestational age-adjusted values are used. Due to methodological confounding involved in calculation of base deficit, lactate may replace base deficit as an acid-base outcome parameter at birth.

Is induced labour in the nullipara associated with more maternal and perinatal morbidity?

To ascertain any differences in foetomaternal outcomes in induced and spontaneous labour among nulliparous women delivering at term. A retrospective matched cohort study consisting of 403 nulliparous women induced at ≥ 292 days and 806 nulliparous women with spontaneous labour at 285-291 days. Compared to those in spontaneous labour, women who had induction of labour were three times more likely to have a caesarean delivery (OR 3.1, 95% CI 2.4-4.1; P < 0.001). Women who had induction of labour were 2.2 times more likely to have oxytocin augmentation (OR 2.2, 95% CI 1.7-2.8; P < 0.001), 3.6 times more likely to have epidural anaesthesia (OR 3.6, 95% CI 2.8-4.6; P < 0.001), 1.7 times more likely to have uterine hyperstimulation (OR 1.7, 95% CI 1.1-2.6), 2 times more likely to have a suspicious foetal heart rate trace (OR 2.0, 95% CI 1.5-2.6), 4.1 times more likely to have blood loss over 500 ml (OR 4.1, 95% CI 2.9-5.5; P < 0.001), and 2.9 times more likely to stay in hospital beyond 5 days (OR 2.9, 95% CI 1.5-5.6; P < 0.001). Babies born to mothers who had induction of labour were significantly more likely to have an Apgar score of <5 at 5 min and an arterial cord pH of <7.0. Compared to those with spontaneous labour, nulliparous women with induced labours are more likely to have uterine hyperstimulation, caesarean delivery, and babies with low Apgar scores. Nulliparous women should be made aware of this, as well as potential risks of expectant management during counseling.

Chain of Brain Preservation—A concept to facilitate early identification and initiation of hypothermia to infants at high risk for brain injury

Background Therapeutic hypothermia has been associated with improved outcomes in term infants particularly in those who present with moderate hypoxic-ischemic encephalopathy (HIE). However, in the three major studies the time to initiate cooling was at approximately 4.5 postnatal hours. Objective To determine in term infants who meet criteria for therapeutic hypothermia whether specific clinical and/or biochemical parameters might identify those high risk infants destined for abnormal neurodevelopmental outcome even sooner than is currently possible. Design/methods Retrospective chart review for the following parameters: gestational age, birth weight, sex, labor complications, mode of delivery, 10 min Apgar ≤ 3, cardio-pulmonary resuscitation in the delivery room, cord arterial pH and base deficit, initial postnatal pH and base deficit obtained within 1 h, aEEG, Sarnat staging and seizures at enrollment. Abnormal outcome included death and neurodevelopmental deficits. Results At a single tertiary care center in a metropolitan area, 45 term infants with moderate to severe HIE were treated with selective head cooling initiated at a mean of 4.69 ± 0.79 h of life; 43/45 (96%) were outborn. Five (11%) infants died and of survivors 26 (58%) are normal and 14 (31%) infants are abnormal at follow-up ranging from 12 to 26 months. Infants with abnormal vs. normal outcome were of comparable gestational age, birth weight with no differences in any parameters between groups except that in infants with abnormal vs. normal outcome the postnatal pH obtained within the first postnatal hour was lower, i.e. 6.87 ± 0.15 vs. 7.00 ± 0.22 ( p = 0.02) and abnormal infants were more likely to present with severe encephalopathy, i.e. 15/19 (79%) vs. 6/26 (23%) ( p = 0.0002) and clinical seizures, i.e. 14/19 (74%) vs.10/26 (38%) ( p = 0.03) on admission. Conclusions High risk infants who become candidates for therapeutic hypothermia and ultimately have an abnormal outcome may be identified by an additional early postnatal biochemical marker, i.e. the presence of profound metabolic acidosis. An earlier induction of hypothermia that currently occurs particularly in infants with severe encephalopathy may potentially improve outcome. Given that most infants are outborn, a time sensitive education metaphor termed Chain of Brain Preservation may facilitate early recognition of high risk infants and thus earlier treatment.

A case of tuberculosis causing extensive surgical maternal morbidity and poor neonatal outcome

The incidence of tuberculosis in pregnancy in UK is increasing among ethnic minority women.A 25 year old Indian woman with a BMI of 17 was booked in her first pregnancy.Her...

Strength of association between umbilical cord pH and perinatal and long term outcomes: systematic review and meta-analysis

Objective To evaluate the association between umbilical cord pH at birth and long term outcomes.Design Systematic review and meta-analysis.Data sources Medline (1966-August 2008), Embase (1980-August 2008), the Cochrane Library (2008...

Active Second-Stage Management in Twin Pregnancies Undergoing Planned Vaginal Delivery in a U.S. Population

To estimate neonatal morbidity and delivery outcomes according to planned mode of delivery in twin pregnancies with active second-stage management. This was an historic cohort of twin pregnancies delivered in one practice between June 2005 and September 2009 using a strict protocol of second-stage management, including breech extraction of a second noncephalic twin and internal version of a nonengaged cephalic second twin followed by breech extraction. Primary outcome was a 5-minute Apgar score less than 7 for twin B. Secondary outcomes were 5-minute Apgar score less than 7 for twin A and 1-minute Apgar score less than 7 and arterial cord pH below 7.20 for each twin. A total of 287 twin pregnancies were included. There were 157 patients (54.7%) in the planned cesarean group and 130 patients (45.3%) in the planned vaginal delivery group. There was no significant difference in the rates of twin B having a 5-minute Apgar score lower than 7 or an arterial cord pH below 7.20. Among the patients in the planned vaginal delivery group, the cesarean delivery rate was 15.4%. No patients had a vaginal delivery of twin A followed by cesarean delivery of twin B. Among the patients in the planned vaginal delivery group, patients who had a successful vaginal delivery were more likely to be younger (31.56+/-6.6 compared with 36.88+/-6.1 years, P=.001) and were more likely to have a prior vaginal delivery (47.3% compared with 15.0%, P=.007). Planned vaginal delivery of twin pregnancies seems to be associated with neonatal outcomes similar to those with planned cesarean delivery. Active second-stage management is associated with good neonatal outcomes and a low risk of combined vaginal-cesarean delivery. II.

General versus spinal anaesthesia for elective caesarean sections: effects on neonatal short-term outcome. A prospective randomised study

Objective. To compare neonatal short-term outcome in patients who underwent spinal, general anaesthesia and conversion from spinal to general anaesthesia.Methods. One hundred seventy-nine pregnant women undergoing elective caesarean section were allocated randomly to general (n = 89) or spinal anaesthesia (n = 90) and compared with 63 patients who required conversion to general anaesthesia. Umbilical cord artery pH, Apgar score as well as its individual parameter and need for assisted ventilation were evaluated.Results. No differences were found in pH values (p = 0.35), while the need for assisted ventilation differed significantly (p = 0.001). The rate of depressed newborns was 1.1% in the spinal group, 25.9% in the general group and 12.7% in the conversion group with a significant difference for all comparisons. At 5-min, all newborns were vigorous. At 1 min, a higher score for each parameter was found in spinal group with respect to general group, while ‘activity’, ‘grimace’ and ‘respiration’ showed a higher score in conversion group than in general group. At 5 min, a difference was found only for ‘activity’.Conclusions. All kinds of anaesthesia seem to be safe, but loco-regional blockade shows more advantages on the neonatal outcome also when a conversion is necessary.

Maternal and neonatal outcome with trial of operative vaginal delivery (TOVD) in theatre

The objective of this study is to know the maternal and neonatal morbidity, along withcharacteristics affecting the success of trial of operative vaginal delivery (TOVD) intheatre. This is a retrospective study of TOVD in theatre. There were 196 cases ofTOVD in theatre out of 2945 deliveries during the period of study with a total failurerate of 25.5% for all instruments used. Caesarean section and sequential instrumentaldeliveries were associated with more major complications than Neville-Barnesforceps and Kiwi ventouse cup but none with Moolgaoker and Kielland rotationalforceps deliveries. However, the numbers may be small to make a conclusion that Moolgaoker and Kielland rotational forceps had the lowest failure rate (1/16 or 6%). Non-occipitoanterior positions significantly increased the incidence of TOVD (p 0.05, no significant difference). Table 2 illustrates the major complications in 89 parturient’s and 93 babies who had TOVD and in whom notes could be reviewed. Figure 2 Table 2: Illustrate major complications with various TOVDs ANOVA for four independent samples (Table 3) to compare different fetal blood sampling results between: Kiellands, Moolgaoker, sequential instrumental delivery and CS showed that no significant difference in umbilical cord arterial or venous pH between groups (Two tailed p value is 0.07) Figure 3 Table 3: Fetal blood samples for different modes of deliveries in the study: Kiellands, Moolgaoker, sequential instrumental delivery and CS. Moolgaoker and Kielland rotational forceps had lower failure rate (6%), compared to NBF (12.5%), Kiwi (39.2%), and Sequential instrumental delivery (29.3%). ANOVA analysis between the different means has shown significant longer hospital stay for sequential instrumental deliveries and CS (p = 0.017), with an average stay of 3.88 and 5.23 days respectively. DISCUSSION There are no absolute criteria for a TOVD in theatre [3] but the RCOG [1] has suggested that higher failure rates are associated with: 1. Maternal body mass index greater than 30 2. Estimated fetal weight greater than 4000 g or a clinically big baby 3. Occipito-posterior position 4. Mid-cavity delivery or when 1/5 head palpable per abdomen. It had been reported earlier that between 2% to 5% of all instrumental deliveries are undertaken in theatre with preparations made for immediate caesarean section [4, 5]. Patients need to be reassessed again in theatre under regional analgesia and a final decision made regarding the mode of delivery and the appropriate selection of instrument. Failure rates of OVD range from 16% to 20% cases [6, 7]. The failure rate in our study was at 25.5% and that the TOVD with Kiwi has had the lowest success rate between instruments (Failure rate of 39.2%). The experience of the surgeon affects the outcome of OVD, but it is difficult to compare the success rates for different Maternal and neonatal outcome with trial of operative vaginal delivery (TOVD) in theatre 3 of 4 surgeons as they use different instruments. Moreover, an experienced obstetrician is likely to have a higher success rate due to careful patient selection. A cautious less experienced operator may also have a high success rate by performing most of his/her OVD as trials in theatre [8]. In a recent prospective case-control study it has been shown that formal training and education was associated with improved safety of instrumental vaginal delivery for both the mother and the baby [6]. There is higher maternal and fetal morbidity after failed sequential instrumental delivery [9]. Although we found that CS and sequential instrumental deliveries were more associated with complications than with the NBF and Kiwi ventouse cup, this may be due to selection bias. Therefore, we cannot conclude with enough confidence that the latter statement is true. CONCLUSION A larger prospective study to compare the different instruments in TOVD is needed. Non-occipitoanterior positions significantly increased the incidence of TOVD Failure rate of 25.5% for all instruments used. References Maternal and neonatal outcome with trial of operative vaginal delivery (TOVD) in theatre 4 of 4 Author Information A Sayasneh Women’s Health Directorate, Medway Maritime Hospital, Windmill Road, Gillingham, Kent, ME7 5NY, U. K. H Muppala Women’s Health Directorate, Medway Maritime Hospital, Windmill Road, Gillingham, Kent, ME7 5NY, U. K. J Rafi Women’s Health Directorate, Medway Maritime Hospital, Windmill Road, Gillingham, Kent, ME7 5NY, U. K. W Hassan Women’s Health Directorate, Medway Maritime Hospital, Windmill Road, Gillingham, Kent, ME7 5NY, U. K. M Hanson Women’s Health Directorate, Medway Maritime Hospital, Windmill Road, Gillingham, Kent, ME7 5NY, U. K.

375: Ductus venosus flow velocity waveforms indices and arterial cord pH in IUGR fetuses delivered at 32 weeks

In IUGR fetuses, an abnormal ductus venosus (DV) Doppler is considered an ominous sign because it is thought to be related to irreversible decompensation and acidemia. Several indices have been described to quantify DV Doppler waveforms: a) pulsatility index (PI); b) a-wave reversed flow (RF); and, c) SIA index [peak systolic velocity/(isovolumetric relaxation + a-wave)]. The aim of this study was to determine which index is more highly correlated with acidemia at birth.

369: Portal vein Doppler in IUGR fetuses delivered at 32 weeks

Animal studies have shown increased blood flow through the ductus venosus proportionate to the severity of fetal hypoxia. Although data suggest this also occurs in the human fetus, it has never been demonstrated. The aim of this study was to characterize the portal vein (PV) Doppler, which has a monophasic pattern in normal fetuses, from the time of diagnosis of IUGR to delivery of the fetus. Initial assessment with PV Doppler occurred at the time of diganosis of IUGR (EFW<10th percentile and abnormal umbilical artery pulsatility index); the final study occurred within 24 hours of delivery. PV waveforms were correlated to perinatal death or acidemia at birth. Umbilical artery cord pH was evaluated at birth [considered abnormal if the value was <7.10 and/or the base deficit was <-9.0 (2 SD below the mean for preterm neonates)]. Fisher's exact test was used for statistical analysis. PV Doppler waveforms were assessed on 69 occasions in 14 IUGR fetuses (median: 4 studies; range: 2-10). The median gestational age (GA) at the time of the first study was 26.6 weeks (range: 21.6-30.1 weeks) and at the last study was 28.4 weeks (range: 25-31.6 weeks). Three distinct and progressive Doppler patterns were observed: a) monophasic; b) biphasic; and, c) reversed flow. 86% of the PV Dopplers were monophasic and 14% were biphasic at the 1st examination. Of those that were biphasic, 100% progressed to reversed flow. 50% of those that were monophasic progressed to biphasic and 33% of those progressed to reversed flow. Five fetuses had an adverse perinatal outcome: 3 IUFDs and 2 fetuses who were acidemic at birth. All 5 fetuses had either biphasic (n=2) or reversed flow (n=3) patterns. Among the other 9 fetuses, 7 had monophasic and 2 had biphasic patterns (p<0.05). Our study indicates that in IUGR fetuses, PV biphasic or reversed flow patterns are ominous Doppler findings. The data suggest that in IUGR fetuses there is an increased liver vascular resistance with a decreased amount of blood flow rich in oxygen to the liver.

Urgent Cesarean Delivery for Fetal Bradycardia

To estimate whether fetal bradycardia-to-delivery interval or decision-to-delivery interval was related to cord arterial pH according to different causes of fetal distress. Women who delivered singleton neonates by urgent cesarean delivery because of intrapartum fetal bradycardia were retrospectively categorized into three groups according to the cause of fetal bradycardia: 1) Irreversible; 2) Potentially Reversible; and 3) Unknown (no identifiable cause). Comparisons were made between groups in regard to pH, bradycardia-to-delivery interval, and decision-to-delivery interval. Correlation analyses between pH and both intervals were then performed for different groups. Of 235 cases, 39, 22, and 174 were respectively categorized into the Irreversible group, Potentially Reversible group, and Unknown group. The median pH was lower in the Irreversible group (7.094; interquartile range [IQR] 6.991-7.216) than in Potentially Reversible group (7.162; IQR 7.064-7.251) or Unknown group (7.210; IQR 7.161-7.255) (P<.001). The Irreversible group's median bradycardia-to-delivery interval was 5 minutes shorter than those of the other two groups (11 compared with 16.5 and 16 minutes, respectively; P<.001), whereas its median decision-to-delivery interval was 1 minute shorter (10 compared with 11.5 and 11 minutes, respectively; P=.001). In the Irreversible group, pH decreased with the bradycardia-to-delivery interval (Spearman's rho=-0.354; P=.027) at a rate of 0.011 per minute. Cord arterial pH did not correlate with the bradycardia-to-delivery interval in the Potentially Reversible and Unknown groups. In neither group did pH correlate with decision-to-delivery interval. Cord arterial pH deteriorates with bradycardia-to-delivery interval when the underlying cause of fetal distress is irreversible, but not so otherwise. II.

Nulliparous patients with small stature delivering at term have an increased risk of secondary cesarean section

To evaluate the obstetric outcome of pregnant patients with small stature (<5th percentile) with regard to the mode of delivery, maternal injuries, and neonatal parameters. Retrospective cohort analysis of 13 years of deliveries. Two groups: group A, patients with a height below the 5th percentile, and group B, patients with a body height between the 25th and 75th percentile. Patients with a body height between the 25th and 75th percentiles showed significantly more spontaneous vaginal deliveries. Secondary cesarean sections (CS) were significantly seen more often in mothers with a small body height. The fetal outcome did not differ significantly between both groups (APGAR, arterial cord pH, base excess). Patients with body height below the 5th percentile were found to have a significantly higher rate of secondary CS. As less than half of our patients with a body height below the 5th percentile were found to have delivered spontaneously at term, pregnancies in small patients should be recognized by obstetricians to be at a specific risk. Whereas the neonatal outcome appears to be comparable between nulliparous women with a body height below the 5th percentile and those with a body height between the 25th and 75th percentiles, small mothers carry a significantly elevated risk of surgical delivery, which should be addressed in prospective studies and in counseling these patients.

Acidemia at Birth, Related to Obstetric Characteristics and to Oxytocin Use, During the Last Two Hours of Labor

During the active phase of the second stage of labor, with maternal expulsive efforts, there is a decline in fetal pH values and an increase in lactic acid concentrations. Little information is available on the association between the occurrence of acidemia at birth and oxytocin use during the second stage of labor. This case-control study compares uterine contraction frequency, oxytocin use, and other obstetric parameters during the last 2 hours of labor in neonates with acidemia (umbilical artery pH <7.05) and without acidemia (cord artery pH ≥7.05) at birth. Cardiotocography tracings were recorded in a blinded fashion. A hyperactive contraction pattern was defined as 6 or more contractions/10 minutes. A total of 304 neonates with acidemia were identified among 28,486 singleton newborns ≥34-weeks’ gestational age delivered at 2 university hospitals in Sweden between 1994 and 2004. Baseline neonatal and obstetric characteristics were similar in the cases and controls. Oxytocin administration during the last 2 hours of labor was more common in cases compared with controls (61.2% vs. 41.7%, P < 0.001). Risk factors associated with acidemia at birth in univariate analysis were ≥6 contractions/10 minutes [odds ratio (OR) 4.94 with a 95% confidence interval (CI) of 3.25–7.49, P < 0.001]; oxytocin use (OR 2.20 with a 95% CI of 1.66–2.92, P < 0.001); bearing down ≥45 minutes (OR 1.77 with a 95% CI of 1.31–2.38, P < 0.001); and occipito-posterior position (OR 2.18 with a 95% CI of 1.19–3.98, P < 0.01). Multivariate logistic regression analysis showed that only ≥6 contractions/10 minutes (OR 5.36 with a 95% CI of 3.32–8.65) and oxytocin use (OR 1.89 with a 95% CI of 1.21–2.97) were independent risk factors for acidemia. Of the cases with hyperactive labor, 75% had received oxytocin. Cardiotocography patterns were abnormal in 68.8% of cases and in 26.1% of controls (P < 0.001). These findings are consistent with previous reports showing an association between hyperactive uterine contraction patterns and fetal acidemia. The investigators believe that this is the first study to demonstrate that oxytocin use is a risk factor for acidemia after adjustment for the influence of uterine contraction frequency.

360: Aortic isthmus reversed flow and arterial cord pH in fetuses delivered at 29 weeks and weighing < 750 grams

360: Aortic isthmus reversed flow and arterial cord pH in fetuses delivered at 29 weeks and weighing < 750 grams