Cerebral autoregulation in different hypertensive disorders of pregnancy.

OBJECTIVE: Cerebrovascular complications that are associated with hypertensive disorders of pregnancy (preeclampsia, chronic hypertension [CHTN], and gestational hypertension [GHTN]) are believed to be associated with impaired cerebral autoregulation, which is a physiologic process that maintains blood flow at an appropriate level despite changes in blood pressure. The nature of autoregulation dysfunction in these conditions is unclear. We therefore evaluated autoregulation in 30 patients with preeclampsia, 30 patients with CHTN, and 20 patients with GHTN and compared them with a control group of 30 normal pregnant women. STUDY DESIGN: The autoregulatory index (ARI) was calculated with the use of simultaneously recorded cerebral blood flow velocity in the middle cerebral artery (transcranial Doppler ultrasound), blood pressure (noninvasive arterial volume clamping), and end-tidal carbon dioxide during a 7-minute period of rest. ARI values of 0 and 9 indicate absent and perfect autoregulation, respectively. We use analysis of variance with Bonferroni test vs a control group. Data are presented as mean ± standard deviation. RESULTS: ARI was significantly reduced in preeclampsia (ARI, 5.5 ± 1.6; P = .002) and CHTN (ARI, 5.6 ± 1.7; P = .004), but not in GHTN (ARI, 6.7 ± 0.8; P = 1.0) when compared with control subjects (ARI, 6.7 ± 0.8). ARI was more decreased in patients with CHTN who subsequently experienced preeclampsia than in those who did not (ARI, 3.9 ± 1.9 vs 6.1 ± 1.2; P = .001). This was not true for women with GHTN or control subjects who later experienced preeclampsia. CONCLUSION: Pregnant women with CHTN or preeclampsia (even after exclusion of superimposed preeclampsia) have impaired autoregulation when compared with women with GHTN or normal pregnancy. Whether the decreased ARI in patients with CHTN who later experience preeclampsia is due to preexistent differences or early affected cerebral circulation remains to be determined.

Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach.

OBJECTIVE: The purpose of this study was to test the hypothesis that a standardized multidisciplinary treatment approach in patients with morbidly adherent placenta, which includes accreta, increta, and percreta, is associated with less maternal morbidity than when such an approach is not used (nonmultidisciplinary approach). STUDY DESIGN: A retrospective cohort study was conducted with patients from 3 tertiary care hospitals from July 2000 to September 2013. Patients with histologically confirmed placenta accreta, increta, and percreta were included in this study. A formal program that used a standardized multidisciplinary management approach was introduced in 2011. Before 2011, patients were treated on a case-by-case basis by individual physicians without a specific protocol (nonmultidisciplinary group). Estimated blood loss, transfusion of packed red blood cells, intraoperative complications (eg, vascular, bladder, ureteral, and bowel injury), neonatal outcome, and maternal postoperative length of hospital stay were compared between the 2 groups. RESULTS: Of 90 patients with placenta accreta, 57 women (63%) were in the multidisciplinary group, and 33 women (37%) were in the nonmultidisciplinary group. The multidisciplinary group had more cases with percreta (P = .008) but experienced less estimated blood loss (P = .025), with a trend to fewer blood transfusions (P = .06), and were less likely to be delivered emergently (P = .001) compared with the nonmultidisciplinary group. Despite an approach of indicated preterm delivery at 34-35 weeks of gestation, neonatal outcomes were similar between the 2 groups. CONCLUSION: The institution of a standardized approach for patients with morbidly adherent placentation by a specific multidisciplinary team was associated with improved maternal outcomes, particularly in cases with more aggressive placental invasion (increta or percreta), compared with a historic nonmultidisciplinary approach. Our standardized approach was associated with fewer emergency deliveries.

Gout in pregnancy: a case report and review of the literature.

While gout is a common inflammatory joint disease, its occurrence in women in their reproductive years is very rare. This is thought to be the result of the uricosuric effect of estrogen. The higher estrogen levels during pregnancy are believed to protect the mother against an acute gout flare. We report a case of a patient with gout who experienced a flare in the third trimester of her pregnancy and a review of the English literature on gout in pregnancy. In addition to this case, we identified 19 pregnancies in 8 women with a diagnosis of gout. Of those, 6 experienced an antepartum flare and 7 a postpartum flare. Our patient developed a gout flare in the third trimester of the pregnancy, which was otherwise complicated by gestational diabetes. Her flare was well controlled with pharmacotherapy (hydrocodone and allopurinol). We hypothesize that her pregnancy induced insulin resistance, which decreased the renal excretion of urate provoked this flare. Little is known about the treatment of acute gout and long-term management during pregnancy. The initiation of preventive treatment with allopurinol should be based on individualized risks and benefits, but we suggest that gestational diabetes justifies its use in the second half of pregnancy.

The effect of neuraxial anesthesia on maternal cerebral hemodynamics.

OBJECTIVE: Neuraxial anesthesia is known to reduce sympathetic tone and mean arterial pressure. Effects on cerebral hemodynamics in pregnancy are not well known. We hypothesize that cerebral hemodynamic parameters will change with respect to baseline following regional analgesia/anesthesia. STUDY DESIGN: We performed maternal transcranial Doppler of the middle cerebral artery in 20 women receiving epidural analgesia for labor, and 18 undergoing spinal anesthesia for cesarean section at baseline, 5 and 15 minutes. Systemic blood pressure (BP), systolic/diastolic/mean velocity, resistance and pulsatility index (PI) were recorded. Cerebral perfusion pressure, critical closing pressure (CrCP), resistance area product, and cerebral flow index were calculated. RESULTS: Epidural placement was associated with significant decreases in systolic/diastolic BP/mean velocity/CrCP after 15 minutes, with a corresponding increase in PI. In the spinal group, systolic/diastolic BP/mean velocity uniformly decreased and remained low after 15 minutes, and PI significantly increased and remained constant after 15 minutes. No differences were seen in BP or cerebral hemodynamics between the groups. CONCLUSION: This study demonstrates that both epidural analgesia and spinal anesthesia result in measurable cerebral hemodynamic changes in normotensive term pregnancy that are likely to be clinically insignificant as they do not affect perfusion pressure or flow.

Changes in maternal posterior and anterior cerebral artery flow velocity during pregnancy and postpartum--a longitudinal study.

BACKGROUND: To evaluate the normal range of blood flow velocity in the maternal anterior (ACA) and posterior cerebral arteries (PCA) along the normal pregnancy and postpartum period. METHODS: Transcranial Doppler ultrasound was used to measure the systolic, diastolic, and mean blood velocities in the ACA and PCA during normal gestation. The resistance and pulsatility indices were calculated. Data were analyzed using multilevel modeling, incorporating random effects models, to construct mean and percentile curves. RESULTS: We performed 355 measurements on 59 patients, which showed that systolic and mean velocity in the ACA decreased, whereas diastolic velocity increased in the PCA during normal pregnancy. Resistance and pulsatility indices in both vessels increased to a maximum in the second trimester, decreased during the third trimester, and increased during the postpartum period. CONCLUSIONS: This study provides normative data for ACA and PCA velocity and indices during pregnancy and postpartum, demonstrating changes in velocity that suggest a shift of cerebral blood flow from the anterior to the posterior cerebral circulation.

Maternal heart rate patterns in the first and second stages of labor.

Objective. To analyze typical maternal heart rate (MHR) patterns in the first and second stages of labor. Design. Observational study. Setting. Tertiary care community hospital. Population. Normal term parturients with epidural anesthesia. Methods. Confirmed MHR and uterine activity were simultaneously recorded. The average MHR was analyzed 10 seconds before, as well as at the peak of, each contraction and/or pushing effort. Each woman contributed one datapoint at each time point to the analysis. Main outcome measure. Change in MHR during contractions. Results. First stage: 7.6±2.1 contractions per woman (n=18) were analyzed. Average MHR decreased during contractions: from 83±13 to 74±10bpm; p<0.001). In 56% (10/18) of the women, 'early' type decelerations were seen in at least 50% of contractions. Second stage: 3.5±1.5 contractions per woman. All women (n=15) showed MHR accelerations during every pushing effort (ΔMHR: +35±13bpm; 88±14 to 123±17bpm; p<0.001). MHR was persistently >100bpm in three women (17%) in the first stage, and in four women (27%) in the second stage. Peak MHR >140bpm occurred during pushing in 20%. Conclusion. Decreases in MHR during contractions in the first stage of labor can mimic fetal heart rate (FHR) accelerations as well as early type decelerations. Thus, first stage tracings with a low baseline and early type decelerations may be maternal in origin and FHR should be independently confirmed in such tracings. Because second stage MHR accelerations generally show greater amplitude than FHR accelerations, tracings with repetitive accelerations during contractions (especially when Δ >20bpm) should be considered MHR until proven otherwise.

The effect of low-dose oxytocin infusion on cerebral hemodynamics in pregnant women.

We investigated the cerebrovascular effects of continuous infusion of low-dose oxytocin in normal pregnant women undergoing induction of labor. In our prospective observational study, middle cerebral artery velocity was measured with transcranial Doppler ultrasound in 25 healthy, normotensive, nonsmoking patients undergoing induction of labor. No vasoactive drugs were used before or during the study period. Measurements were made at baseline and 15, 30, 60, and 120 minutes after oxytocin initiation. Mean arterial pressure, cerebral perfusion pressure, resistance index, resistance area product, and cerebral flow index at different times were calculated and compared using one-way analysis of variance (ANOVA) for repeated measures or Friedman repeated-measures ANOVA as appropriate, with P<0.05 regarded as significant. No significant systemic or cerebrovascular changes were noted after oxytocin initiation, and there was no correlation between the dosage administered and any hemodynamic parameter. Induction-dose oxytocin does not significantly affect selected cerebral hemodynamic parameters in the first 2 hours after initiation.

Hospital readmission after delivery: evidence for an increased incidence of nonurogenital infection in the immediate postpartum period.

OBJECTIVE: The purpose of this study was to analyze reasons for postpartum readmission. STUDY DESIGN: We conducted a database analysis of readmissions within 6 weeks after delivery during 2007, with extended (180 day) analysis for pneumonia, appendicitis, and cholecystitis. Linear regression analysis, survival curve fitting, and Gehan-Breslow statistic with Holm-Sidak all-pairwise analysis for multiple comparisons were used. Probability values of < .05 were considered significant. RESULTS: Of 222,751 women delivered, 2655 women (1.2%) were readmitted within 6 weeks (0.83% vaginal delivery and 1.8% cesarean section delivery; P < .001). A high percentage of these readmittances occurred within the first 6 weeks: pneumonia (84%), appendicitis (43%), or cholecystitis (46%). Cumulative readmission rates were higher in the first 6 weeks after delivery than in the next 20 weeks (pneumonia curve gradient, 3.7 vs 0.11; appendicitis curve gradient, 1.1 vs 0.36; cholecystitis curve gradient, 6.6 vs 1.7). CONCLUSION: The cause of postpartum readmission is primarily infectious in origin. A recent pregnancy appears to increase the risk of pneumonia, appendicitis, and cholecystitis.

Changes in cerebral autoregulation in the second half of pregnancy and compared to non-pregnant controls.

OBJECTIVE: The mechanism by which pregnancy affects the cerebral circulation is unknown, but it has a central role in the development of neurological complications in preeclampsia, which is believed to be related to impaired autoregulation. We evaluated the cerebral autoregulation in the second half of pregnancy, and compared this with a control group of healthy, fertile non-pregnant women. METHODS: In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (noninvasive arterial volume clamping), and end-tidal carbon dioxide (EtCO2) were simultaneously collected for 7min. The autoregulation index (ARI) was calculated. ARI values of 0 and 9 indicated absent and perfect autoregulation, respectively. ANOVA and Pearson's correlation coefficient were used, with p<0.05 considered significant. RESULTS: A total of 76 pregnant and 18 non-pregnant women were included. The ARI did not change during pregnancy, but pregnant women had a significantly higher ARI than non-pregnant controls (ARI 6.7±0.9 vs. 5.3±1.4, p<0.001). This remained significant after adjusting for EtCO2 (p<0.001). CONCLUSION: Cerebral autoregulation functionality is enhanced in the second half of pregnancy, when compared to non-pregnant fertile women, even after controlling for EtCO2. The autoregulation does not change with advancing gestational age.

Teen Pregnancy: Are Pregnancies following an Elective Termination Associated with Increased Risk for Adverse Perinatal Outcomes?

STUDY OBJECTIVE: The authors sought to determine whether pregnancies in adolescents following an abortion of pregnancy is associated with an elevated risk for adverse perinatal outcomes. METHODS: In a cohort study of all adolescent (younger than 18 years) deliveries over a 4-year period at 1 institution, we compared nulliparous women with a history of a prior abortion (cases) to those without a spontaneous loss or abortion of pregnancy (referent) for adverse perinatal outcomes, including preterm birth and fetal growth restriction. RESULTS: Of the 654 included nulliparous adolescent deliveries, 102 (16%) had an abortion before the index pregnancy. Compared with the referent group, adolescents with a history of a abortion were older (17.8 ± 0.8 vs 16.7 ± 1.2 years, P = .0001), enrolled earlier for prenatal care (14.4 ± 5.6 vs 17.2 ± 7.6 weeks, P = .0004), along with a higher incidence of African American race (95% vs 88%, P = .05). The groups did not differ with respect to other maternal demographics. Perinatal outcomes, including spontaneous preterm birth, abnormal placentation, birth weight, and gestational age at delivery, did not differ between the 2 groups. CONCLUSION: Compared with adolescent women who had just delivered and did not have a prior abortion, women who had just delivered and had a previous abortion were more likely to be older at the age of their first pregnancy and more likely to initiate early prenatal care. Thus, having a prior abortion may improve the health of a pregnancy though adverse outcomes do not differ between the 2 groups.

Effect of breath holding on cerebrovascular hemodynamics in normal pregnancy and preeclampsia.

Preeclampsia (PE) is associated with endothelial dysfunction and impaired autonomic function, which is hypothesized to cause cerebral hemodynamic abnormalities. Our aim was to test this hypothesis by estimating the difference in the cerebrovascular response to breath holding (BH; known to cause sympathetic stimulation) between women with preeclampsia and a group of normotensive controls. In a prospective cohort analysis, cerebral blood flow velocity (CBFV) in the middle cerebral artery (transcranial Doppler), blood pressure (BP, noninvasive arterial volume clamping), and end-tidal carbon dioxide (EtCO2) were simultaneously recorded during a 20-s breath hold maneuver. CBFV changes were broken down into standardized subcomponents describing the relative contributions of BP, cerebrovascular resistance index (CVRi), critical closing pressure (CrCP), and resistance area product (RAP). The area under the curve (AUC) was calculated for changes in relation to baseline values. A total of 25 preeclamptic (before treatment) and 25 normotensive women in the second half of pregnancy were enrolled, and, 21 patients in each group were included in the analysis. The increase in CBFV and EtCO2 was similar in both groups. However, the AUC for CVRi and RAP during BH was significantly different between the groups (3.05 ± 2.97 vs. -0.82 ± 4.98, P = 0.006 and 2.01 ± 4.49 vs. -2.02 ± 7.20, P = 0.037), indicating an early, transient increase in CVRi and RAP in the control group, which was absent in PE. BP had an equal contribution in both groups. Women with preeclampsia have an altered initial CVRi response to the BH maneuver. We propose that this is due to blunted sympathetic or myogenic cerebrovascular response in women with preeclampsia.

Cerebral autoregulation in pregnancies complicated by diabetes and overweight.

AIM: The aim of this study was to estimate the impact of diabetes and obesity on cerebral autoregulation in pregnancy. METHODS: Cerebral autoregulation was evaluated in women with gestational diabetes, type 2 diabetes mellitus and/or overweight (body mass index ⩾ 25 kg m(-2)) and compared to a cohort of euglycaemic pregnant women. The autoregulation index was calculated using simultaneously recorded cerebral blood flow velocity in the middle cerebral artery and blood pressure. Autoregulation index values of 0 and 9 indicate absent and perfect autoregulation, respectively. RESULTS: Autoregulation index in women with either diabetes (n = 33, 6.6 ± 1.1) or overweight (n = 21, 6.7 ± 0.6) was not significantly different to that in control patients (n = 23, 6.6 ± 0.8, p = 0.96). CONCLUSION: Cerebral autoregulation is not impaired in pregnant women who have non-vasculopathic diabetes or overweight. This suggests that the increased risk of pre-eclampsia in diabetic and overweight women is not associated with early impaired cerebral autoregulation.

Cerebral autoregulation in normal pregnancy and preeclampsia.

OBJECTIVE: To test the hypothesis that preeclampsia is associated with impaired dynamic cerebral autoregulation. METHODS: In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (determined by noninvasive arterial volume clamping), and end-tidal carbon dioxide were simultaneously collected during a 7-minute period of rest. The autoregulation index was calculated. Values of 0 and 9 indicated absent and perfect autoregulation, respectively. Student t test was used, with P<.05 considered significant. RESULTS: Women with preeclampsia (before treatment, n=20) and their normotensive counterparts (n=20) did not differ with respect to baseline characteristics, except for earlier gestational age at delivery (36 3/7 [24 4/7-40 2/7] compared with 39 2/7 [32 0/7-41 0/7]; P<.001) and higher blood pressure in women with preeclampsia. Autoregulation index was significantly reduced in preeclamptic women compared with normotensive women in the control group (5.5±1.7 compared with 6.7±0.6; P=.004). There was no correlation between the autoregulation index and blood pressure. CONCLUSION: Women with preeclampsia have impaired dynamic cerebral autoregulation. The fact that blood pressure does not correlate with autoregulation functionality may explain why cerebral complications such as eclampsia can occur without sudden or excessive elevation in blood pressure. LEVEL OF EVIDENCE: II.

Neonatal side effects of maternal labetalol treatment in severe preeclampsia.

OBJECTIVE: Labetalol is often used in severe preeclampsia (PE). Hypotension, bradycardia and hypoglycemia are feared neonatal side effects, but may also occur in (preterm) infants regardless of labetalol exposure. We analyzed the possible association between intrauterine labetalol exposure and such side effects. STUDY DESIGN: From 1 January 2003 through 31 March 2008, all infants from mothers suffering severe PE admitted to one tertiary care center were included. Severe PE was defined according to the International Society for the Study of Hypertension in Pregnancy (ISSHP) criteria. Infants exposed to labetalol in utero (labetalol infants) were compared with infants, who were not exposed to labetalol (controls). Neonatal records were reviewed for hypotension (RR