Maternal catecholamines decrease during labor after lumbar epidural anesthesia

Preeclamptic heart failure - perioperative concerns and management: a narrative review

Preeclampsia is an important cause of heart failure during pregnancy and the postpartum period. The aim of this review is to elucidate the pathophysiology and clinical features of preeclamptic heart failure and describe the medical and anesthetic management of these high-risk parturients. This article reviews the current evidence base regarding preeclamptic heart failure and its pathophysiology, types, and clinical features. We also describe the medical and anesthetic management of these patients during the peripartum period. Heart failure due to preeclampsia can present as either systolic or diastolic dysfunction. The management strategies of systolic heart failure include dietary salt restriction, diuresis, and cautious use of beta-blockers and vasodilators. Diuretics are the mainstay in the treatment of diastolic heart failure. In the absence of obstetric indications, vaginal delivery is the safest mode of delivery in these high-risk patients, and the use of an early labor epidural for analgesia is recommended. These patients would require increased invasive monitoring during labor and vaginal delivery. Neuraxial and general anesthesia have been used successfully for cesarean section in these patients but require crucial modifications of the standard technique. Uterotonic drugs have significant cardiovascular and pulmonary effects, and a clear understanding of these is essential during the management of these patients. Preeclamptics with heart failure require individualized peripartum care, as cardiac decompensation is an important risk factor for maternal and neonatal morbidity and mortality. These high-risk parturients benefit from timely multidisciplinary team inputs and collaborated management.

Efficacy and Safety of Epidural Chloroprocaine for Breakthrough Pain During Labor Analgesia: A Prospective, Double-Blind, Randomized Trial

INTRODUCTION

A significant number of women who undergo neuraxial labor analgesia experience breakthrough pain. Prompt mitigation of breakthrough pain is essential to improve maternal and fetal outcomes. We evaluated epidural chloroprocaine compared with ropivacaine in alleviating labor breakthrough pain.

METHODS

We performed a double-blind randomized controlled clinical trial between May and July 2023. Eligible parturients received epidural analgesia with ropivacaine and sufentanil. Those with breakthrough pain were randomized to receive either 0.125% epidural ropivacaine (group R) or chloroprocaine at concentrations of 0.5% (group C1), 1.0% (group C2), or 1.5% (group C3), all in a volume of 6 mL. The primary outcome was the treatment success rate, indicated by a decrease of at least 4 points on the numerical rating scale pain score 9 min after analgesic injection. Secondary outcomes and adverse effects were also recorded.

RESULTS

Out of 323 patients receiving epidural analgesia, 192 experienced breakthrough pain. After exclusion of three patients because of protocol deviation, there were 47, 48, 47, and 47 patients in group R, C1, C2, and C3, respectively. Group C3 demonstrated a higher treatment success rate (39/47, 83.0%) in managing breakthrough pain than group R (26/47, 55.3%), group C1 (12/48, 25.0%), and group C2 (30/47, 63.8%) (p < 0.001). Group C3 had lower numerical rating scale scores at 6 and 9 min after injection and required fewer patient-controlled epidural boluses than other groups. In addition, group C3 reported greater satisfaction than the other groups (p < 0.001). No significant differences were observed in obstetric or neonatal outcomes across these groups.

CONCLUSION

Parturients experiencing breakthrough pain could receive 1.5% epidural chloroprocaine, rather than lower chloroprocaine concentrations and ropivacaine, to achieve more rapid and better pain relief with higher patient satisfaction.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2300071069, http://www.chictr.org.cn/index.aspx .

Effect of intrapartum epidural analgesia on rate of emergency delivery for presumed fetal compromise: nationwide registry-based cohort study

OBJECTIVES

To determine the rate of emergency delivery for presumed fetal compromise after epidural analgesia (EDA) compared with that after alternative analgesia or no analgesia, and to assess whether this rate is increased in pregnancies with reduced placental reserve.

METHODS

This was a nationwide registry-based cohort study of 629 951 singleton pregnancies delivered at 36 + 0 to 42 + 0 weeks of gestation that were recorded in the Dutch national birth registry between 2014 and 2018, including 120 426 cases that received EDA, 86 957 that received alternative analgesia and 422 568 that received no analgesia during labor. Pregnancies with congenital anomaly, chromosomal abnormality, fetal demise, planned Cesarean delivery, non-cephalic presentation at delivery and use of multiple forms of analgesia were excluded. The primary outcome was emergency delivery for presumed fetal compromise. Secondary outcomes included delivery characteristics and neonatal outcome. Negative binomial regression analysis was stratified by parity and results are presented according to birth-weight centile, after adjusting for confounding.

RESULTS

Among women who received EDA, 13.2% underwent emergency delivery for presumed fetal compromise, compared with 4.1% of women who had no analgesia (relative risk (RR), 3.23 (95% CI, 3.16-3.31)) and 7.0% of women who received alternative analgesia (RR, 1.72 (95% CI, 1.67-1.77)). Independent of birth weight, the RR of presumed fetal compromise after EDA vs no analgesia was higher in parous women (adjusted RR (aRR), 2.15 (95% CI, 2.04-2.27)) compared with nulliparous women (RR, 1.88 (95% CI, 1.84-1.94)). Stratified for parity, the effect of EDA was modified significantly by birth-weight centile (interaction P-value, < 0.001 for nulliparous and 0.004 for parous women). The emergency delivery rate following EDA was highest in those with a birth weight < 5th centile (25.2% of nulliparous and 16.6% of parous women), falling with each increasing birth-weight centile category up to the 91st -95th centile (11.8% of nulliparous and 7.2% of parous women).

CONCLUSIONS

Intrapartum EDA is associated with a higher risk of emergency delivery for presumed fetal compromise compared with no analgesia and alternative analgesia, after adjusting for relevant confounding. The highest rate of emergency delivery for presumed fetal compromise was observed at the lowest birth-weight centiles. RRs of emergency delivery for presumed fetal compromise after EDA were modestly but consistently modified by birth-weight centile, supporting the hypothesis that the adverse effects of EDA are exacerbated by reduced placental function. While EDA provides effective pain relief during labor, alternative strategies for pain management may be preferable in pregnancies with a high background risk of fetal compromise. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Tranexamic acid for the prevention of postpartum bleeding in women with anaemia: Statistical analysis plan for the WOMAN-2 trial: an international, randomised, placebo-controlled trial

Background: Postpartum haemorrhage (PPH) is responsible for over 50,000 maternal deaths every year. Most of these deaths are in low- and middle-income countries. Tranexamic acid (TXA) reduces bleeding by inhibiting the enzymatic breakdown of fibrin blood clots. TXA decreases surgical bleeding and reduces deaths from bleeding after traumatic injury. When given within three hours of birth, TXA reduces deaths from bleeding in women with PPH. However, for many women, treatment of PPH is too late to prevent death. World-wide, over one-third of pregnant women are anaemic and many are severely anaemic. These women have an increased risk of PPH and are more likely to die if PPH occurs. There is an urgent need to identify ways to prevent severe postpartum bleeding in anaemic women. The WOMAN-2 trial will quantify the effects of TXA on postpartum bleeding in women with anaemia. Results: This statistical analysis plan (version 1.0; dated 22 February 2023) has been written based on information in the WOMAN-2 Trial protocol version 2.0, dated 30 June 2022. The primary outcome of the WOMAN-2 trial is the proportion of women with a clinical diagnosis of primary PPH. Secondary outcomes are maternal blood loss and its consequences (estimated blood loss, haemoglobin, haemodynamic instability, blood transfusion, signs of shock, use of interventions to control bleeding); maternal health and wellbeing (fatigue, headache, dizziness, palpitations, breathlessness, exercise tolerance, ability to care for her baby, health related quality of life, breastfeeding); and other health outcomes (deaths, vascular occlusive events, organ dysfunction, sepsis, side effects, time spent in higher level facility, length of hospital stay, and status of the baby). Conclusions: WOMAN-2 will provide reliable evidence about the effects of TXA in women with anaemia. Registration: WOMAN-2 was prospectively registered at the International Standard Randomised Controlled Trials registry ( ISRCTN62396133) on 07/12/2017 and ClinicalTrials.gov on 23/03/2018 ( NCT03475342).

Association between Maternal Neuraxial Analgesia and Neonatal Outcomes in Very Preterm Infants

Background  Although the use of neuraxial analgesia has been shown to improve uteroplacental blood flow and maternal and fetal hemodynamics related to labor pain, possibly improving immediate outcomes in term neonates, the association between neuraxial analgesia use and outcomes in preterm neonates remains unclear. Objective  The aim of this article was to evaluate the association between maternal use of neuraxial analgesia and neonatal outcomes in very preterm infants. Methods  This is a retrospective cohort study of women delivering singleton neonates between 23 and 32 weeks' gestation at a large academic center between 2012 and 2016. Outcomes of neonates born to women who used neuraxial analgesia for labor and/or delivery were compared to those whose mothers did not. Multivariable logistic regression was utilized to assess the independent associations of neuraxial analgesia use with neonatal outcomes after controlling for potential confounders, including gestational age, mode of delivery, and existing interventions to improve neonatal outcomes of prematurity. Results  Of 478 eligible women who delivered singleton very preterm neonates in this study period, 352 (73.6%) used neuraxial analgesia. Women who used neuraxial analgesia were more likely to have delivered at a later preterm gestational age, to have a higher birthweight, to have preeclampsia and/or hemolysis, elevated liver enzymes, low platelet count (HELLP), to have undergone labor induction, to have delivered by cesarean delivery, and to have received obstetric interventions such as magnesium prophylaxis for fetal neuroprotection, antenatal corticosteroids for fetal lung maturity, and antibiotics prior to delivery; they were less likely to have been diagnosed with a clinical abruption. Neuraxial analgesia was associated with decreased incidence of cord umbilical artery pH less than 7.0 (24.7 vs. 34.9%, p  = 0.03), as well as decreased incidence of neonatal intensive care unit length of stay over 60 days (35.5 vs. 48.4%, p  = 0.01), although these associations did not persist on multivariable analysis. On multivariable analyses, neuraxial analgesia remained independently associated with decreased odds of necrotizing enterocolitis (adjusted odds ratio [aOR]: 0.28, 95% confidence interval [CI]: 0.12-0.62) and grade III/IV intraventricular hemorrhage (aOR: 0.33, 95% CI: 0.13-0.87). These associations remained significant on sensitivity analyses, which were performed between 10 and 90% of the overall cohort in order to control for outliers, as well as between the subgroup of patients who received obstetric interventions. Conclusions  Maternal neuraxial analgesia use may be associated with lower odds of adverse outcomes in very preterm infants, even after controlling for existing interventions for prematurity. Prior work has suggested such effects may be due to improved neonatal acid-base status from changes in placental perfusion and maternal pain management, but further work is required to prospectively investigate such associations.

Effects of neuraxial analgesia technique on labor and maternal-fetal outcomes: a retrospective study

PURPOSE

To compare the effects of epidural analgesia (EA) and combined spinal epidural analgesia (SEA) on labor and maternal-fetal outcomes.

METHODS

We retrospectively identified and included 1499 patients with a single cephalic fetus who delivered at the study center from January 2015 to December 2018 and received neuraxial analgesia at the beginning of the active phase of labor (presence of regular painful contractions and cervical dilatation between 4 and 6 cm). Data including analgesia, labor characteristics, and maternal-fetal outcomes were retrieved from the prospectively collected delivery room database and medical records.

RESULTS

SEA was associated with a shorter first stage of labor than EA, with a median difference of 60 min. On multivariable ordinal logistic regression analysis, neuraxial analgesia, gestational age, fetal weight, labor induction, and parity were independently associated with the first stage length: patients in the EA group were 1.32 times more likely to have a longer first stage of labor (95% CI 1.06-1.64, p = 0.012) than those in the SEA group. Additionally, a significantly lower incidence of fundal pressure was performed among patients who underwent SEA (OR 0.55, 95% CI 0.34-0.9, p = 0.017). No associations were observed between the used neuraxial analgesia technique and other outcomes.

CONCLUSIONS

SEA was associated with a shorter length of the first stage of labor and a lower rate of fundal pressure use than EA. Further studies confirming the effects of SEA on labor management and clarifying differences in maternal-fetal outcomes will allow concluding about the superiority of one technique upon the other.

Duration of exposure to epidural anesthesia at delivery, DNA methylation in umbilical cord blood and their association with offspring asthma in Non-Hispanic Black women

Epidural anesthesia is an effective pain relief modality, widely used for labor analgesia. Childhood asthma is one of the commonest chronic medical illnesses in the USA which places a significant burden on the health-care system. We recently demonstrated a negative association between the duration of epidural anesthesia and the development of childhood asthma; however, the underlying molecular mechanisms still remain unclear. In this study of 127 mother-child pairs comprised of 75 Non-Hispanic Black (NHB) and 52 Non-Hispanic White (NHW) from the Newborn Epigenetic Study, we tested the hypothesis that umbilical cord blood DNA methylation mediates the association between the duration of exposure to epidural anesthesia at delivery and the development of childhood asthma and whether this differed by race/ethnicity. In the mother-child pairs of NHB ancestry, the duration of exposure to epidural anesthesia was associated with a marginally lower risk of asthma (odds ratio = 0.88, 95% confidence interval = 0.76-1.01) for each 1-h increase in exposure to epidural anesthesia. Of the 20 CpGs in the NHB population showing the strongest mediation effect, 50% demonstrated an average mediation proportion of 52%, with directional consistency of direct and indirect effects. These top 20 CpGs mapped to 21 genes enriched for pathways engaged in antigen processing, antigen presentation, protein ubiquitination and regulatory networks related to the Major Histocompatibility Complex (MHC) class I complex and Nuclear Factor Kappa-B (NFkB) complex. Our findings suggest that DNA methylation in immune-related pathways contributes to the effects of the duration of exposure to epidural anesthesia on childhood asthma risk in NHB offspring.

Plasmatic catecholamines after neuraxial labour analgesia: A randomised controlled trial comparing epidural versus combined spinal-epidural

BACKGROUND

Combined spinal-epidural technique (CSE) for labour analgesia has been associated with fetal bradycardia and uterine hypertonia when compared with epidural analgesia (EA), possibly due to a decrease in epinephrine levels following neuraxial anaesthesia. However, there are no recent studies comparing plasmatic catecholamines levels between those two techniques. This study aimed to compare CSE versus EA regarding pre- and post-analgesia catecholamines levels, uterine tone and fetal heart rate.

PATIENTS AND METHODS

Randomised clinical trial with 47 labouring patients divided in two groups (CSE and EA). Primary outcome was plasmatic catecholamine measurements before and after neuraxial block. Secondary outcomes were fetal heart rate changes, uterine hypertonia, hypotension episodes, pain relief and fetal outcomes.

RESULTS

For CSE group, the median decrease of plasmatic epinephrine was 0 pg/mL [(-) 480-(+) 41] and for norepinephrine was -21 pg/mL [(-) 2507-(+) 94]. For EA group, the median decrease for epinephrine was 0 pg/mL [(-) 326-(+) 15] and for norepinephrine was -5 pg/mL [(-) 190-(+76)]. There were no differences between groups (p = 0.96 and p = 0.63 for epinephrine and norepinephrine, respectively). There were no differences for secondary outcomes.

CONCLUSIONS

There was no evidence of a more significant decrease of catecholamines with CSE when compared with EA. Catecholamines decrease theory may not be valid for modern labour analgesia techniques.

Vaginal birth after cesarean in women with no prior vaginal delivery carrying a large for gestational age baby

BACKGROUND

To study the factors associated with successful labor after cesarean (LAC) among women with no prior vaginal delivery, delivering a large for gestational age (LGA) baby.

METHODS

A retrospective case-control study at two tertiary medical centers in Israel, including all women undergoing LAC with no prior vaginal delivery during 2010-2020, delivering a singleton LGA newborn. Factors associated with successful vaginal delivery were examined by a multivariable analysis.

RESULTS

Overall, 323/505 (64.0%) had a successful LAC. Arrest of labor as the indication for previous CD was less common in the LAC success group [39 (12.1%) vs. 58 (31.9%), P < .001]. The rate of epidural analgesia was higher in the LAC success group [249 (77.1%) vs. 122 (67.0%), P = .014]. The rate of weight centile ≥97th was lower in the LAC success group [64 (19.8%) vs. 51 (28.0%), P = .035], as well as the rate of higher LAC birthweight than previous cesarean birthweight [264 (81.7%) vs. 162 (89.0%), P = .030]. In a multivariable logistic regression analysis, maternal height (aOR [95% CI]:1.09 (1.01, 1.17), P = .014) and epidural anesthesia (aOR [95% CI]:3.68 (1.31, 10.32), P = .013) were the only independent factors associated with LAC success.

CONCLUSIONS

Among primiparous women undergoing LAC carrying LGA newborns, the vaginal delivery rate is acceptable; however, uterine rupture risk is increased. Epidural administration is a modifiable factor and should be taken into consideration during LAC management.

Neuraxial labor analgesia: Initiation techniques

The ideal technique for labor analgesia would have a quick onset, predictable quality, and adjustable depth and duration. Moreover, it would be easy to perform and have minimal maternal and fetal side effects. A catheter-based neuraxial approach encompasses these desirable characteristics and includes the epidural, combined spinal epidural, dural puncture epidural, and intrathecal catheter techniques. In this review, we outline the unique technical considerations, analgesic characteristics, and side effect profiles for each technique that can ultimately impact the maternal-fetal dyad. The selection of neuraxial analgesia techniques should consider the patient and team's goals and expectations, the clinical context, and the institutional culture. Labor analgesic techniques that initiate with an intentional dural puncture component have a faster onset, greater bilateral and sacral spread, and lower rates of epidural catheter failure. Further elucidation of the mechanisms, benefits, and risks of each neuraxial initiation technique will continue to benefit patients and care providers.

Sonographic fetal head circumference is associated with trial of labor after cesarean section success

PURPOSE

The purpose is to study the association of the fetal sonographic head circumference (SHC) with trial of labor after cesarean (TOLAC) success rate, among women with no prior vaginal deliveries.

METHODS

A retrospective case-control study including all women with no prior vaginal delivery undergoing TOLAC during 3/2011-6/2020 with a sonographic estimated fetal weight within one week from delivery. TOLAC success and failure groups were compared.

RESULTS

Of 1232 included women, 948 (76.9%) delivered vaginally. The mean fetal SHC was smaller in the TOLAC success group (330 ± 10 vs. 333 ± 11 mm, p < 0.001). In a multivariate regression analysis, predelivery BMI, hypertensive disorders, gestational age at prior CD, SHC and epidural analgesia administration were independently associated with TOLAC success. A ROC analysis of the multivariable model composed of the factors found independently associated with TOLAC success, excluding SHC, yielded an area under curve of 0.659 (95% CI 0.622-0.697) compared with 0.668 (95% CI 0.630-0.705) with SHC included.

CONCLUSION

Smaller SHC is independently associated with TOLAC success among women that did not deliver vaginally before, and has additive clinical value for the prediction of TOLAC success when combined with non-sonographic factors.

Obstetric Anesthesia and Heart Disease: Practical Clinical Considerations

Maternal morbidity and mortality as a result of cardiac disease is increasing in the United States. Safe management of pregnancy in women with heart disease requires appropriate anesthetic, cardiac, and obstetric care. The anesthesiologist should risk stratify pregnant patients based upon cardiac disease etiology and severity in order to determine the appropriate type of hospital and location within the hospital for delivery and anesthetic management. Increased intrapartum hemodynamic monitoring may be necessary and neuraxial analgesia and anesthesia is typically appropriate. The anesthesiologist should anticipate obstetric and cardiac emergencies such as emergency cesarean delivery, postpartum hemorrhage, and peripartum arrhythmias. This clinical review answers practical questions for the obstetric anesthesiologist and the nonsubspecialist anesthesiologist who regularly practices obstetric anesthesiology.

Trial of Labor After Cesarean of Small for Gestational Age Neonates Among Women with No Prior Vaginal Delivery - a Retrospective Study

To evaluate the characteristics and outcomes of women who had never delivered vaginally and underwent a trial of labor after cesarean (TOLAC) of small for gestational age (SGA) neonates, and to identify risk factors for unplanned repeat cesarean delivery. A retrospective cohort study from two tertiary medical centers. All women undergoing a TOLAC with no prior vaginal delivery, delivering a singleton SGA neonate at term between 2005 and 2020 were included. Factors associated with successful vaginal delivery were examined by a multivariable analysis. Of the 255 women who met the inclusion criteria and underwent TOLAC, 72.2% delivered vaginally. In a multivariable analysis, maternal height [adjusted odds ratio (aOR) (95% CI): 1.10 (1.02-1.19), p = 0.012] and epidural administration [aOR (95% CI): 2.78 (1.0-7.73), p = 0.050] were positively independently associated with TOLAC success, and hypertensive disorders were negatively independently associated with TOLAC success [aOR (95% CI): 0.52 (0.004-0.74), p = 0.029]. The success rate of TOLAC among women with no prior vaginal delivery, delivering a SGA neonate is relatively high. Maternal height, hypertensive disorders, and epidural administration are independent factors associated with TOLAC success. Epidural administration is a modifiable factor and should be taken in consideration during TOLAC management.

Maternal haemodynamics during labour epidural analgesia with and without adrenaline

OBJECTIVES

Labour is one of the most painful experiences in a woman's life. Epidural analgesia using low-concentration local anaesthetics and lipophilic opioids is the gold standard for pain relief during labour. Pregnancy in general, particularly labour, is associated with changes in maternal haemodynamic variables, such as cardiac output and heart rate, which increase and peak during uterine contractions. Adrenaline is added to labour epidural solutions to enhance efficacy by stimulating the α2-adrenoreceptor. The minimal effective concentration of adrenaline was found to be 2 μg mL^-1 for postoperative analgesia. The addition of adrenaline may also produce vasoconstriction, limiting the absorption of fentanyl into the systemic circulation, thereby reducing foetal exposure. However, adrenaline may influence the haemodynamic fluctuations, possibly adding to the strain on the circulatory system. The aim of this study was to compare the haemodynamic changes after application of labour epidural analgesia with or without adrenaline 2 μg mL^-1.

METHODS

This was a secondary analysis of a single-centre, randomised double-blind trial. Forty-one nulliparous women in labour requesting epidural analgesia were randomised to receive epidural solution of bupivacaine 1 mg mL^-1, fentanyl 2 μg mL^-1 with or without adrenaline 2 μg mL^-1. The participants were monitored using a Nexfin CC continuous non-invasive blood pressure and cardiac output monitor. The primary outcomes were changes in peak systolic blood pressure and cardiac output during uterine contraction within 30 min after epidural activation. The effect of adrenaline was tested statistically using a linear mixed-effects model of the outcome variables' dependency on time, adrenaline, and their interaction.

RESULTS

After excluding three patients due to poor data quality and two due to a malfunctioning epidural catheter, 36 patients (18 in each group) were analysed. The addition of adrenaline to the solution had no significant effect on the temporal changes in peak systolic blood pressure (p=0.26), peak cardiac output (0.84), or heart rate (p=0.91). Furthermore, no significant temporal changes in maternal haemodynamics (peak systolic blood pressure, p=0.54, peak cardiac output, p=0.59, or heart rate p=0.55) were associated with epidural analgesia during 30 min after epidural activation in both groups despite good analgesia.

CONCLUSIONS

The addition of 2 μg mL^-1 adrenaline to the epidural solution is not likely to change maternal haemodynamics during labour.

A systematic review with network meta-analysis on mono strategy of anaesthesia for preeclampsia in caesarean section

The aim of this study was to reveal the effects of anaesthesia strategies on maternal mean arterial pressure (MAP), heart rate, vasopressor consumption, adverse events, and neonatal resuscitation when women with preeclampsia (PE) undergo caesarean section (CS). Three major databases were searched for randomized controlled trials (RCTs) and prospective controlled studies (PCSs). Two authors independently screened, extracted, and checked eligibility and outcome data. Outcomes involved MAP, vasopressor use, maternal adverse events, APGAR scores, and neonatal resuscitation. Pooled estimates were carried out by contrast-based network meta-analysis, and pooled effect sizes were presented with 95% confidence interval (CI). Eleven RCTs and one PCS (n = 782) formed three-node network meta-analysis, and non-significant differences were observed in MAP, 5-min APGAR score, and neonatal intubation rate among the three anaesthesia strategies. General anaesthesia had significantly lower vasopressor consumption than spinal anaesthesia did (standardised mean difference =  - 1.19, 95% confidence interval [CI]: - 1.76 to - 0.63), but it had higher maternal adverse event rate (risk ratio = 2.00, 95% CI 1.16-3.47). Because no optimal anaesthesia strategy has been shown to achieve a balanced maternal and neonatal outcome, therefore a shared decision-making process may be required regarding the most suitable choice of anaesthetic strategy for individual preeclamptic mother undergoing CS. Future larger studies may need to focus on evaluating the role of vasopressors on maternal hemodynamic as well as factors affecting maternal outcomes for different anaesthetic techniques in preeclamptic women undergoing CS.

Peripartum management of a patient with catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal cardiac channelopathy characterized by episodes of ventricular tachycardia (VT) during exercise or in stressful situations. As the peripartum period creates a stressful environment, we describe our approach of this rare condition in a very common situation, child birth.

The association between neuraxial anesthesia and the development of childhood asthma - a secondary analysis of the newborn epigenetics study cohort

Objectives: Childhood asthma is a common chronic illness that has been associated with mode of delivery. However, the effect of cesarean delivery alone does not fully account for the increased prevalence of childhood asthma. We tested the hypothesis that neuraxial anesthesia used for labor analgesia and cesarean delivery alters the risk of developing childhood asthma.Methods: Within the Newborn Epigenetics Study birth cohort, 196 mother and child pairs with entries in the electronic anesthesia records were included. From these records, data on maternal anesthesia type, duration of exposure, and drugs administered peripartum were abstracted and combined with questionnaire-derived prenatal risk factors and medical records and questionnaire-derived asthma diagnosis data in children. Logistic regression models were used to evaluate associations between type of anesthesia, duration of anesthesia, and the development of asthma in males and females.Results: We found that longer duration of epidural anesthesia was associated with a lower risk of asthma in male children (OR = 0.80; 95% CI = 0.66-0.95) for each hour of epidural exposure. Additionally, a unit increase in the composite dose of local anesthetics and opioid analgesics administered via the spinal route was associated with a lower risk of asthma in both male (OR = 0.59, 95% CI = 0.36-0.96) and female children (OR 0.26, 95% CI 0.09-0.82).Conclusion: Our data suggest that peripartum exposure to neuraxial anesthesia may reduce the risk of childhood asthma primarily in males. Larger human studies and model systems with longer follow-up are required to elucidate these findings.

Characteristics of labor-onset hypertension persist after neuraxial labor analgesia

AIM

This study aimed to investigate the rate of labor-onset hypertension (LOH) under neuraxial labor analgesia and the effect of neuraxial labor analgesia on LOH.

METHODS

A retrospective study was conducted in a tertiary university hospital from 2015 to 2016. Patients who were admitted to the hospital for vaginal delivery under combined spinal and epidural anesthesia were selected. LOH was defined as the elevation of systolic blood pressure (BP) to ≥140 mmHg or diastolic BP to ≥90 mmHg for the first time after the onset of labor. Cases of LOH that persisted after neuraxial labor analgesia (prolonged LOH) were further analyzed to determine the hypertension severity and therapeutic intervention rate.

RESULTS

Among 775 patients, 213 (28.4%) developed LOH. Prolonged LOH was observed in 30 patients (3.9%). LOH severity and the likelihood of prolonged LOH were positively correlated. Therapeutic intervention was administered only to the patients with prolonged LOH, that is, to 100% of those with emergent hypertension, to 21.1% of those with severe hypertension during labor, and to 36.8% of those with severe hypertension, to 55.6% of those with mild hypertension in the post-partum period.

CONCLUSION

The rate of LOH was reduced significantly after neuraxial labor analgesia. Patients with prolonged LOH should be carefully followed up during labor and in the post-partum period because such patients often require antihypertensive therapy.

Effect of epidural anesthesia in labor; pregnancy with cardiovascular disease

OBJECTIVE

We studied the effect and safety of epidural anesthesia during labor in pregnant women with cardiovascular disease.

MATERIALS AND METHODS

In the pregnant women with cardiovascular disease, we compared maternal outcome and suppressive effect on blood pressure retrospectively between the epidural group (anesthetized epidurally during labor) and the no-epidural group (not anesthetized epidurally during labor).

RESULTS

A total of 277 patients were included in the analyses. Cardiovascular events decreased significantly in epidural group (P < 0.05). Cardiovascular events occurred in 12 (epidural group) and 2 (no-epidural group) of cases (P < 0.05). Cardiovascular events are all events related to arrhythmia. In the epidural group, the systolic blood pressure showed no increase in labor (110.5 mmHg, 95% CI; 95-132 mmHg vs. 110 mmHg, 95% CI; 91-130 mmHg). In the no-epidural group, the systolic blood pressure increased in labor (107 1 mmHg, 95% CI; 96-138 mmHg vs. 123 mmHg, 95% CI; 105-153 mmHg; P < 0.05).

CONCLUSION

Epidural anesthesia had decrease of the cardiovascular events related to arrhythmia and the effect of significantly suppression raising the blood pressure during labor in pregnant women with cardiovascular disease. In pregnant women with the cardiovascular disease, epidural anesthesia during labor may be available.

The effect of labor epidural analgesia on maternal-fetal outcomes: a retrospective cohort study

PURPOSE

To evaluate the impact of labor epidural analgesia on maternal-fetal safety outcomes in a signal Chinese academic medical center.

METHODS

A single-intervention impact study was conducted at The Second Affiliated Hospital, Wenzhou Medical University. The study period was divided into three phases: (1) baseline phase: from January 1 and June 30, 2009 when no analgesic method was routinely employed during labor; (2) phase-in period: the epidural analgesia was implemented 8 a.m.-5 p.m. during weekdays; and (3) the post-No Pain Labor N'Delivery phase when the labor epidural was applied 24 h a day, 7 days a week, from June 1, 2010 and June 30, 2011. The maternal-fetal safety outcomes of delivery were compared between the different periods.

RESULTS

There were 15,415 deliveries with 42.3% of nulliparous parturients in the 31-month study period. As the primary outcomes, the labor epidural analgesia rate increased from 0 to 57%, the vaginal delivery rate increased, and cesarean delivery rate decreased by 3.5% after full implementation. As the secondary outcomes, the rate of episiotomy and severe perineal injury after the implementation periods were significant decreased. The rate of postpartum oxytocin administration was decreased by 17.8%. No significant difference between the baseline and implementation periods was found in the rate of postpartum hemorrhage, Apgar scores less than 7 at both 1 and 5 min, 7-day mortality, and the overall neonatal intensive care unit admission rate.

CONCLUSION

Implementation of labor epidural analgesia increased the vaginal delivery rate and use of labor epidural analgesia is safe to parturients and fetus.

Effects of combined spinal-epidural analgesia on first stage of labor: a cohort study

Background: Neuraxial anesthesia is considered as the gold standard in the control labor of pain. Its variants are epidural analgesia and combined spinal-epidural analgesia. Few studies, as yet, have investigated the duration of labor as a primary outcome. Some authors have suggested that combined spinal-epidural analgesia may reduce labor duration but at the moment the benefit of shortening labor is uncertain. The main aim of this study was to compare combined spinal-epidural with epidural analgesia in terms of their effect on duration of stage I labor, maternal, and neonatal outcomes. Methods: A prospective cohort study was conducted. Parturients who requested analgesia at cervical dilatation <6 cm were included. Analgesia was either epidural with low concentration levobupivacaine or combined spinal epidural with subarachnoid sufentanil. The primary outcome was the length of stage I labor. Onset and quality of analgesia, mode of delivery, effects on uterine activity and use of oxytocin, fetal heart rate abnormalities and uterine hyperkinesia, maternal, and neonatal complications were also considered. Results: We enrolled 400 patients: 176 in the combined spinal-epidural group and 224 in the epidural group. Patients in the two treatment groups were similar with regard to demographic characteristics, parity, and incidence of obstetric comorbidities, labor induction, oxytocin infusion, Bishop score, and Visual Analogue Score (VAS) at analgesia request. Duration of stage I labor did not differ, at 195 (120-300) minutes for both the groups (p = .7). Combined spinal-epidural was associated with less reduction in uterine contractility after initial administration: 15.34 versus 39.73%, (p < .001) and with delayed need for oxytocin, at dilations of 7 ± 2.5 cm versus 6. ± 2.7, (p = .002). Onset of analgesia was quicker for combined spinal-epidural analgesia: 31 versus 20%, with VAS <4 after 5 minutes, (p < .001); and lower VAS scores after initial analgesia administration. No differences were found in the other outcomes. Conclusions: Combined spinal-epidural with subarachnoid sufentanil may not reduce the duration of stage I labor, but in our study it appeared to affect uterine contractility less. It also had a more rapid onset and was more effective, without any concomitant increase in maternal or neonatal complications.

Epidural analgesia at trial of labor after cesarean (TOLAC): a significant adjunct to successful vaginal birth after cesarean (VBAC)

INTRODUCTION

Epidural analgesia has been considered a risk factor for labor dystocia at trial of labor after cesarean (TOLAC) and uterine rupture. We evaluated the association between exposure to epidural during TOLAC and mode of delivery and maternal-neonatal outcomes.

MATERIALS AND METHODS

A single center retrospective study of women that consented to TOLAC within a strict protocol between 2006 and 2013. Epidural "users" were compared to "non-users". Primary outcome was the mode of delivery: repeat in-labor cesarean or vaginal birth after cesarean (VBAC). Secondary outcomes were maternal/neonatal morbidities. Univariate/multivariate analyses for associations between epidural and mode of delivery were adjusted for significant covariates/mediators.

RESULTS

Of a total of 105,471 births registered, 9464 (9.0%) were eligible for TOLAC; 7149 (75.5%) women consented to TOLAC, among which 4081 (57.1%) had epidural analgesia. The in labor cesarean rate was significantly lower for the epidural "users" 8.7% vs. "non-users" 11.8%, P<0.0001, with a parallel increased rate of instrumental delivery. Uterine rupture rates were comparable: 0.4% and 0.29%, respectively (P=0.31). The adjusted multivariate model showed that epidural "users" were more likely to experience a VBAC, odds ratio (OR) 4.58 [3.67; 5.70]; P<0.0001 with a similar rate of adverse maternal-neonatal outcomes.

CONCLUSION

Epidural analgesia at TOLAC may emerge as a safe and significant adjunct for VBAC.

Perioperative considerations for patients with sickle cell disease: a narrative review

PURPOSE

Approximately 200,000 individuals worldwide are born annually with sickle cell disease (SCD). Regions with the highest rates of SCD include Africa, the Mediterranean, and Asia, where its prevalence is estimated to be 2-6% of the population. An estimated 70,000-100,000 people in the United States have SCD. Due to enhanced newborn screening, a better understanding of this disease, and more aggressive therapy, many sickle cell patients survive into their adult years and present more frequently for surgery.

SOURCE

The authors identified relevant medical literature by searching PubMed, MEDLINE®, EMBASE™, Scopus™, Web of Science, and Google Scholar databases for English language publications appearing from 1972-September 2016. Case reports, abstracts, review articles, and original research articles were reviewed-with particular focus on the pathophysiology and medical management of SCD and any anesthesia-related issues.

PRINCIPAL FINDINGS

Perioperative physicians should be familiar with the triggers of a sickle cell crisis and vaso-occlusive disease. Sickle cell disease affects various organ systems, including the central nervous, cardiovascular, pulmonary, genitourinary, and musculoskeletal systems. Preoperative assessment should focus on end-organ dysfunction. Controversy continues regarding if and when sickle cell patients should receive transfusions and which anesthetic technique (regional or general) confers any benefits. Timely, appropriate, and sufficient analgesia is critical, especially when patients experience a vaso-occlusive crisis, acute chest syndrome, or acute postoperative pain.

CONCLUSION

Effective management of SCD patients in the perioperative setting requires familiarity with the epidemiology, pathophysiology, clinical manifestations, and treatment of SCD.

Outcomes of induced versus spontaneous labor

PURPOSE

Induced labor is associated with a higher request for analgesia than spontaneous labor. This study compared duration of labor, mode of delivery, quantity of blood loss, type of perineal outcome and neonatal outcomes between women in induced labor and women in spontaneous labor, both on epidural analgesia (administered at cervical dilation  ≤ 4 cm).

METHODS

In a two-year longitudinal cohort study, data were gathered from nulliparous women with a single cephalic pregnancy of at least 37 weeks attending the labor and delivery ward in Policlinico San Matteo Fundation-Pavia. Data were compared for women with early labor analgesia in (1) spontaneous labor (Robson group 1) and (2) induced labor (dinoprostone - vaginal insert or gel, Robson group 2a).

RESULTS

Of the 1104 women who underwent epidural analgesia in the study period, 531 were included: 326 in spontaneous labor and 205 in induced labor. The only significant difference found was duration of the first stage, which lasted 305 (200-390) min in spontaneous labor compared to 205 min (120-345) in induced labor (p  <0.001).

CONCLUSIONS

In women on early epidural analgesia, induction is associated with a shorter duration of the first stage of labor and does not affect other outcomes.

Labor epidural analgesia and the incidence of instrumental assisted delivery

OBJECTIVE

To assess the influence of labor epidural analgesia on the course of labor and to determine its association with instrumental assisted delivery rate.

MATERIALS AND METHODS

A retrospective case-control study was performed during 2007-2011 aiming to identify the relation between epidural analgesia (EA) and instrumental assisted delivery (IAD) rate. All patients in whom instrumental assistance for delivery was applied were allocated into either case (parturients who received EA and had IAD) or control (parturients who did not receive EA but had IAD) groups. Maternal demographic data, pregnancy and delivery characteristics as well as neonatal short-term outcome were studied.

RESULTS

A total of 7675 vaginal deliveries occurred during the study period and 187 (2.43%) patients had IAD. Vacuum extraction was applied to 67 (2.16%) parturients who received EA, and to 120 (2.61%) who did not. The median duration of the first stage of labor was 510 min in the EA group as compared to 390 min in the control group (P=0.001). The median duration of the second stage of labor among cases and controls was 60 and 40 min, respectively (P<0.0005). Cases more often had their labor induced by oxytocin 80.3% as compared to 58.3% among controls (P=0.003). There was no significant association between the use of EA and increased IAD rate (OR=0.81; 95% CI, 0.60-1.09).

CONCLUSIONS

Labor EA did not increase the incidence of IAD and the risk of adverse neonatal outcomes, but was associated with prolonged first and second stages of labor.

Impact of the introduction of neuraxial labor analgesia on mode of delivery at an urban maternity hospital in China

OBJECTIVE

To evaluate the association between the introduction of neuraxial (epidural) labor analgesia and mode of delivery in a large urban maternity hospital in China.

METHODS

A single-intervention impact study was conducted at Shijiazhuang Obstetrics and Gynecology Hospital in Shijiazhuang. Baseline data collection occurred between August 1 and December 31, 2009, when no analgesic method was routinely employed during labor. An intervention was then implemented, consisting of a neuraxial labor analgesia service. The service was fully operational from September 1, 2010, and data were collected to August 31, 2011. The mode of delivery was compared between the different periods.

RESULTS

Neuraxial analgesia rate was used in none of the 3787 deliveries during the baseline period and 3429 (33.5%) of 10 230 in the implementation period. Cesareans were performed in 1533 (40.5%) deliveries in the baseline period and 3441 (33.6%) in the implementation period (difference -6.8%, 99.8% confidence interval [CI] -9.7% to -3.9%; P<0.0017). The proportion of vaginal deliveries in which forceps were used was unchanged (difference -0.8%, 99.8% CI -0.7% to 2.2%; P=0.92).

CONCLUSION

The introduction of epidural analgesia reduced the frequency of cesarean delivery, which improved obstetric and neonatal outcomes.

Combined spinal-epidural analgesia in labour: its effects on delivery outcome

BACKGROUND AND OBJECTIVES

Combined spinal-epidural (CSE) has become an increasingly popular alternative to traditional labour epidural due to its rapid onset and reliable analgesia provided. This was a prospective, convenient sampling study to determine the effects of CSE analgesia on labour outcome.

METHODS

One hundred and ten healthy primigravida parturients with a singleton pregnancy of ≥37 weeks gestation and in the active phase of labour were studied. They were enrolled to the CSE (n=55) or Non-CSE (n=55) group based on whether they consented to CSE analgesia. Non-CSE parturients were offered other methods of labour analgesia. The duration of the first and second stage of labour, rate of instrumental vaginal delivery and emergency cesarean section, and Apgar scores were compared.

RESULTS

The mean duration of the first and second stage of labour was not significantly different between both groups. Instrumental delivery rates between the groups were not significantly different (CSE group, 11% versus Non-CSE group, 16%). The slightly higher incidence of cesarean section in the CSE group (16% versus 15% in the Non-CSE group) was not statistically significant. Neonatal outcome in terms of Apgar score of less than 7 at 1 and 5min was similar in both groups.

CONCLUSION

There were no significant differences in the duration of labour, rate of instrumental vaginal delivery and emergency cesarean section, and neonatal outcome in parturients who received compared to those who did not receive CSE for labour analgesia.

Neuraxial analgesia effects on labour progression: facts, fallacies, uncertainties and the future

Approximately 60% of women who labour in the USA receive some form of neuraxial analgesia, but concerns have been raised regarding whether it negatively impacts the labour and delivery process. In this review, we attempt to clarify what has been established as truths, falsities and uncertainties regarding the effects of this form of pain relief on labour progression, negative and/or positive. Additionally, although the term 'epidural' has become synonymous with neuraxial analgesia, we discuss two other techniques, combined spinal-epidural and continuous spinal analgesia, that are gaining popularity, as well as their effects on labour progression.

Regional anesthesia in patients with pregnancy induced hypertension

Pregnancy induced hypertension is a hypertensive disorder, which occurs in 5% to 7% of all pregnancies. These parturients present to the labour and delivery unit ranging from gestational hypertension to HELLP syndrome. It is essential to understand the various clinical conditions that may mimic preeclampsia and the urgency of cesarean delivery, which may improve perinatal outcome. The administration of general anesthesia (GA) increases morbidity and mortality in both mother and baby. The provision of regional anesthesia when possible maintains uteroplacental blood flow, avoids the complications with GA, improves maternal and neonatal outcome. The use of ultrasound may increase the success rate. This review emphasizes on the regional anesthetic considerations when such parturients present to the labor and delivery unit.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Neuraxial analgesia: a review of its effects on the outcome and duration of labor

Labor pain is one of the most challenging experiences encountered by females during their lives. Neuraxial analgesia is the mainstay analgesic for intrapartum pain relief. However, despite the increasing use and undeniable advantages of neuraxial analgesia for labor, there have been concerns regarding undesirable effects on the progression of labor and outcomes. Recent evidence indicates that neuraxial analgesia does not increase the rate of Cesarean sections, although it may be associated with a prolonged second stage of labor and an increased rate of instrumental vaginal delivery. Even when neuraxial analgesia is administered early in the course of labor, it is not associated with an increased rate of Cesarean section or instrumental vaginal delivery, nor does it prolong the labor duration. These data may help physicians correct misconceptions regarding the adverse effects of neuraxial analgesia on labor outcome, as well as encourage the administration of neuraxial analgesia in response to requests for pain relief.

Maternal pulse pressure at admission is a risk factor for fetal heart rate changes after initial dosing of a labor epidural: a retrospective cohort study

OBJECTIVE

To examine low maternal admission pulse pressure (PP) as a risk factor for new onset postepidural fetal heart rate (FHR) abnormalities.

STUDY DESIGN

Retrospective cohort study of nulliparous, singleton, vertex-presenting women admitted to labor and delivery after 37 0/7 weeks that received an epidural during labor. Women with a low admission PP were compared with those with a normal admission PP. The primary outcome was new onset FHR abnormalities defined as recurrent late or prolonged FHR decelerations in the first hour after initial dosing of a labor epidural.

RESULTS

New onset FHR abnormalities, defined as recurrent late decelerations and/or prolonged decelerations, occurred in 6% of subjects in the normal PP cohort compared with 27% in the low PP cohort (odds ratio, 5.6; 95% confidence interval, 2.1-14.3; P < .001). A multivariate logistic regression analysis generated an adjusted odds ratio of 28.9 (95% confidence interval, 3.7-221.4; P < .001).

CONCLUSION

New onset FHR abnormalities after initial labor epidural dosing occur more frequently in women with a low admission PP than those with a normal admission pulse. Admission PP appears to be a novel predictor of new onset postepidural FHR abnormalities.

The influence of analgesia on labor--is it related to primary cesarean rates?

Multiple observational studies have reported an association between neuraxial (epidural, spinal, or combined spinal-epidural) labor analgesia and cesarean delivery. The purpose of this review is to summarize data from controlled trials addressing the question of whether neuraxial labor analgesia causes an increased risk of cesarean delivery. Additionally, the review will discuss whether the timing of initiation of analgesia or the specific type of neuraxial analgesia influences mode of delivery. Finally, the issue of external validity of published trials will be discussed.

Analgesia in Obstetrics

Background: An effective relief of labour pain has become an important part of obstetric medicine. Therefore regional nerve blocks, systemic analgesic and non-pharmacologic techniques are commonly used. This review article gives a summary of pathophysiology and anatomy of labour pain as well as advantages, disadvantages, risks and adverse reactions of analgesic techniques in newborns and parturients. Methods: We performed a selective literature search in Medline via PubMed using the search-terms "Analgesia" and "Obstetrics". We also included the current guidelines of the German Society for Anesthesiology and Intensive Care Medicine. Results: PDA and CSE are safe techniques for the relief of labour pain if contraindications are excluded. The risk for instrumental delivery but not for caesarean section is increased under neuraxial analgesia. PDA and CSE should be performed in an early stage of labour using low doses of local anaesthetics if possible. It is not necessary to wait for a defined cervical dilatation before starting neuraxial analgesia. Anesthesiologists and obstetricians should inform patients as soon as possible before the situation of stress during labour. Systemic opioid analgesia is a possible alternative for neuraxial techniques. Because of possible side effects systemic remifentanil analgesia should only be performed under continuous monitoring. Several nonpharmacologic methods can also relieve labour pain, but results of studies about their effectiveness are inconsistent.

Epidural analgesia during labor vs no analgesia: A comparative study

BACKGROUND

Epidural analgesia is claimed to result in prolonged labor. Previous studies have assessed epidural analgesia vs systemic opioids rather than to parturients receiving no analgesia. This study aimed to evaluate the effect of epidural analgesia on labor duration compared with parturients devoid of analgesia.

METHODS

One hundred sixty nulliparous women in spontaneous labor at full term with a singleton vertex presentation were assigned to the study. Parturients who request epidural analgesia were allocated in the epidural group, whereas those not enthusiastic to labor analgesia were allocated in the control group. Epidural analgesia was provided with 20 mL bolus 0.5% epidural lidocaine plus fentanyl and maintained at 10 mL for 1 h. Duration of the first and second stages of labor, number of parturients receiving oxytocin, maximal oxytocin dose required for each parturient, numbers of instrumental vaginal, vacuum-assisted, and cesarean deliveries and neonatal Apgar score were recorded.

RESULTS

There was no statistical difference in the duration of the active-first and the second stages of labor, instrumental delivery, vacuum-assisted or cesarean delivery rates, the number of newborns with 1-min and 5-min Apgar scores less than 7 between both groups and number of parturients receiving oxytocin, however, the maximal oxytocin dose was significantly higher in the epidural group.

CONCLUSION

Epidural analgesia by lidocaine (0.5%) and fentanyl does not prolong labor compared with parturients without analgesia; however, significant oxytocin augmentation is required during the epidural analgesia to keep up the aforementioned average labor duration.

The health implications of birth by Caesarean section

Since the first mention of fetal programming of adult health and disease, a plethora of programming events in early life has been suggested. These have included intrauterine and postnatal events, but limited attention has been given to the potential contribution of the birth process to normal physiology and long-term health. Over the last 30 years a growing number of studies have demonstrated that babies born at term by vaginal delivery (VD) have significantly different physiology at birth to those born by Caesarean section (CS), particularly when there has been no exposure to labour, i.e. pre-labour CS (PLCS). This literature is reviewed here and the processes involved in VD that might programme post-natal development are discussed. Some of the effects of CS are short term, but longer term problems are also apparent. We suggest that VD initiates important physiological trajectories and the absence of this stimulus in CS has implications for adult health. There are a number of factors that might plausibly contribute to this programming, one of which is the hormonal surge or "stress response" of VD. Given the increasing incidence of elective PLCS, an understanding of the effects of VD on normal development is crucial.