Society for Maternal-Fetal Medicine Consult Series #68: Sickle cell disease in pregnancy.

Pregnant individuals with sickle cell disease have an increased risk of maternal and perinatal morbidity and mortality. However, prepregnancy counseling and multidisciplinary care can lead to favorable maternal and neonatal outcomes. In this consult series, we summarize what is known about sickle cell disease and provide guidance for sickle cell disease management during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations.

Peripheral Anti-Angiogenic Imbalance during Pregnancy Impairs Myogenic Tone and Increases Cerebral Edema in a Rodent Model of HELLP Syndrome.

Using an animal model of hemolysis elevated liver enzymes low platelets (HELLP) that has systemic inflammation and neuroinflammation we wanted to determine if blood brain barrier (BBB) permeability, cerebral edema, vascular tone, and occludin expression were altered in pregnant rats. Anti-angiogenic proteins sFlt-1 and sEng (4.7 and 7 µg/kg/day, respectively) were chronically infused into normal pregnant (NP) rats beginning on gestational day 12 via a mini-osmotic pump. On gestational day 19, blood pressure was measured via a carotid catheter and brains were collected. BBB permeability was assessed in select brain regions from rats infused with 0.5 mg/mL Texas Red Dextran and phenylephrine. Occludin, sFlt-1, and sEng were analyzed via western blot or ELISA. Infusion of sFlt-1 and sEng into NP rats increased hemolysis and liver enzymes, and decreased platelets and led to hypertension. HELLP rats had significant impairment in the myogenic response and increased BBB permeability in the posterior cortex and brainstem. Brain water content in the posterior cortex was increased and sEng protein expression in the brainstem was significantly increased in HELLP rats. The results from this study suggest that a peripheral anti-angiogenic imbalance during pregnancy is associated with decreased myogenic tone, vasogenic edema, and an increase in BBB permeability, but not anti-angiogenic imbalance in the brain.

Hypertension, Anxiety, and Blood-Brain Barrier Permeability Are Increased in Postpartum Severe Preeclampsia/Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome Rats.

Hypertension and inflammation during pregnancy are suggested to contribute to the development of postpartum depression and anxiety. Using a rat model of severe preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, which displays both hypertension and inflammation during pregnancy, we evaluated whether rats were prone to develop depression or anxiety in the postpartum period. On gestational day 12, miniosmotic pumps infusing sFlt-1 (soluble fms-like tyrosine kinase-1) and sEng (soluble endoglin) were placed into rats, a subset of these rats was infused with 2 mg/kg of Orencia (abatacept) the following day to determine whether immune suppression via T-cell depletion prevented any changes in maternal depression or anxiety-like behavior. All rats, including normal pregnant (NP) controls, delivered between gestational days 21 and 22. Postpartum severe preeclamptic rats buried significantly more marbles compared with NP rats ( P=0.002) and Orencia-treated rats ( P=0.05). Severe preeclamptic rats spent significantly more time in closed arms of the elevated plus maze compared with NP rats ( P=0.009) and Orencia-treated rats ( P=0.05). Severe preeclamptic rats were hypertensive compared with NP ( P=0.03) and Orencia-treated rats ( P=0.01). Finally, severe preeclamptic rats had increased blood-brain barrier permeability compared with NP rats ( P=0.03), which was reversed in Orencia-treated rats ( P=0.008). These results suggest that severe preeclampsia/hemolysis, elevated liver enzymes, and low platelet count syndrome during pregnancy contributes to an increase in anxiety-like behavior, blood-brain barrier permeability, and hypertension in the postpartum. The current results suggest that T-cell suppression during pregnancy can also help prevent chronic hypertension and increased anxiety in the postpartum period.

HELLP Syndrome: Pathophysiology and Current Therapies.

HELLP syndrome is a disorder associated with serious maternal morbidity and mortality. Distinguishing HELLP from other pregnancy-related disorders is often challenging and may result in delay of treatment. Differential diagnoses include acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, antiphospholipid syndrome, and hemolytic uremic syndrome, and are reviewed in this chapter. While there is not any current treatment for HELLP, the mainstay of treatment involves maternal stabilization and timely delivery. Various treatment strategies have been attempted to help decrease the morbidity and mortality of HELLP, including the maternal use of corticosteroids. The authors review the studies and controversies surrounding the maternal use of corticosteroids, plasma exchange, and low molecular weight heparin for the treatment of HELLP, as well as the role of the complement system in HELLP. Further large, well-designed, randomized controlled trials are needed to address the role corticosteroids may play in the treatment of women with HELLP and to help improve maternal and fetal outcomes.

Management of Hypertensive Crisis for the Obstetrician/Gynecologist.

Hypertensive disorders of pregnancy are among the leading preventable contributors of maternal and fetal adverse outcomes, including maternal and fetal death. Blood pressure increase has a strong association with unfavorable pregnancy outcomes, including stroke and pulmonary edema. A persistent blood pressure measurement greater than or equal to 160/110 mm Hg lasting for more than 15 minutes, during pregnancy or postpartum, is considered an obstetric emergency and requires rapid appropriate treatment. Following evidence-based guidelines, implementing institutional polices, and understanding the classification and pathophysiology of hypertensive disorders of pregnancy are essential and can significantly improve the rate of preventable complications.

Inhibition of T-cell activation attenuates hypertension, TNFα, IL-17, and blood-brain barrier permeability in pregnant rats with angiogenic imbalance.

PROBLEM: Angiogenic imbalance during pregnancy is associated with immune activation, hypertension, increased T cell infiltration, and neurological insults. METHOD OF STUDY: On gestational day (GD) 12, timed-pregnant rats were infused with anti-angiogenic factors sFlt-1 and sEndoglin (4.7 and 7 µg/kg) to create HELLP syndrome via mini-osmotic pumps for 8 days, with a subset of these rats having Orencia (2 mg/kg) infused on GD13. On GD19, blood-brain barrier (BBB) permeability was evaluated via Evan's Blue infusion, blood was collected for T-cell measurements, inflammatory cytokine secretion. Brain tissues were also collected to examine inflammatory cytokine infiltration. RESULTS: T-cell attenuation with Orencia decreased circulating CD4(+) and CD8(+) T cells, circulating tumor necrosis factor alpha (TNFα) and IL-17, BBB permeability and significantly decreased biochemical evidence of HELLP compared to untreated HELLP rats. CONCLUSIONS: These data support the hypothesis that T cells have a critical role in contributing to the pathophysiology that is seen in angiogenic imbalance during pregnancy.

Higher-dose oxytocin and hemorrhage after vaginal delivery: a randomized controlled trial.

OBJECTIVE: Higher-dose oxytocin is more effective than lower-dose regimens to prevent postpartum hemorrhage after cesarean delivery. We compared two higher-dose regimens (80 units and 40 units) to our routine regimen (10 units) among women who delivered vaginally. METHODS: In a double-masked randomized trial, oxytocin (80 units, 40 units, or 10 units) was administered in 500 mL over 1 hour after placental delivery. The primary outcome was a composite of any treatment of uterine atony or hemorrhage. Prespecified secondary outcomes included outcomes in the primary composite and a decline of 6% or more in hematocrit. A sample size of 600 per group (N=1,800) was planned to compare each of the 80-unit and 40-unit groups to the 10-unit group. At planned interim review (n=1,201), enrollment in the 40-unit group was stopped for futility and enrollment continued in the other groups. RESULTS: Of 2,869 women, 1,798 were randomized as follows: 658 to 80 units; 481 to 40 units; and 659 to 10 units. Most characteristics were similar across groups. The risk of the primary outcome in the 80-unit group (6%; relative risk [RR] 0.93, 95% confidence interval [CI] 0.62-1.40) or the 40-unit group (6%; RR 0.94, 95% CI 0.61-1.47) was not different compared with the 10-unit group (7%). Treatment with additional oxytocin after the first hour was less frequent with 80 units compared with 10 units (RR 0.41, 95% CI 0.19-0.88), as was a 6% or more decline in hematocrit (RR 0.83, 95% CI 0.69-0.99); both outcomes declined with increasing oxytocin dose. Outcomes were similar between the 40-unit and 10-unit groups. CONCLUSION: Compared with 10 units, 80 units or 40 units of prophylactic oxytocin did not reduce overall postpartum hemorrhage treatment when administered in 500 mL over 1 hour for vaginal delivery. Eighty units decreased the need for additional oxytocin and the risk of a decline in hematocrit of 6% or more. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00790062. LEVEL OF EVIDENCE: I.