Hypertensive Disorders Of Pregnancy Flashcards
Definitions:
HTN
Resistant HTN
Severe HTN
Proteinuria
HEELP Syndrome
Adverse conditions of CNS, CVS/Resp/Heme/Renal/Hepatic/Feto-placental
Serious complications of CNS, CVS/Resp/Heme/Renal/Hepatic/Feto-placental
Definitions: Hypertensive Disorders of Pregnancy (HDP)
HTN in pregnancy: SBP ≥140 mmHg and/or DBP ≥90 mmHg (avg of ≥2 measurements @ least 15 mins apart in same arm)
Resistant HTN: need for 3 antihypertensives for BP control @ ≥20 wks gest
Severe HTN: SBP ≥160 mmHg or DBP ≥110 mmHg
Significant proteinuria: ≥0.3 g/d (24 hr collection) or ≥20 mg/mmol (random urine)
Suspect if dipstick ≥1+ protein
HELLP syndrome
Hemolysis
Elevated Liver enzymes
Low Platelets
Adverse condition: increases risk of severe complications (see table)
Serious complication: warrants delivery (see table)
Classification:
Pre-exsiting HTN
Gestational HTN
Preeclampsia
Severe preeclampsia
Classification
Pre-existing HTN (pre-pregnancy or <20 wks gest)
Gestational HTN (develops @ ≥20 wks gest)
w/ or w/o comorbid conditions (ex DM, renal dz)
Preeclampsia: gestational HTN + new proteinuria or ≥1 adverse condition or serious complication
In “pre-existing HTN” population: resistant HTN, new or worsening proteinuria, ≥1 adverse condition or serious complication
Severe preeclampsia: preeclampsia complicated by ≥1 serious complication
Warrants delivery regardless of gestational age
“Other hypertensive effects” (ex transient HTN, white-coat, masked HTN)
Risk Factors
High risk
Moderate risk
Risk factors
High risk
Prior preeclampsia
Pre-pregnancy BMI ≥30
Chronic medical dz (HTN, pre-gestational DM, CKD, SLE/antiphospholipid antibody syndrome)
Assisted reproductive technology
Moderate risk
Prior placental abruption, stillbirth, or FHR
Maternal age ≥40 yrs
1st pregnancy, multiple pregnancy
Prevention (in at risk population)
Prevention (in at risk population)
Low dose ASA qhs (81-162 mg) (start by 16 wks gestation, d/c by 36 wks)
Calcium supplementation if low dietary Ca2+ intake
Exercise
If overweight or obese - dietary advice (reduced calories, low glycemic index foods) & exercise
Treatment:
Severe HTN
Non severe (with and w/o comorbid conditions)
Treatment
Severe HTN
Inpatient care if severe HTN/preeclampsia
Lower BP to SBP <160 mmHg & DBP <110
Initial Rx in hospital
Labetalol 10-80 mg IV q30 min prn or 200 mg po q60 min prn or IV infusion (0.5-2 mg/min)
Short-acting nifedipine capsules 5-10 mg po q30-60 min prn
Methyldopa 1000 mg po
Hydralazine 5-10 mg IV q30 min prn
Alternatives: NTG infusion, po clonidine
Postpartum: po captopril
MgSO4 not recommended as sole anti-HTN Rx
Continuous FHR monitoring until BP stable
Non-severe (SBP 140-159 mmHg, DBP 90-109 mmHg) w/o comorbid conditions
Lower BP to SBP 130-155 mmHg & DBP mmHg ≤85 mmHg
Labetalol 100-300 mg po tid-qid
Nifedipine XL 30-60 mg po od (or 30 mg po bid)
Methyldopa 250-750 po tid-qid
No ACE-Is or ARBs in pregnancy
Non-severe w/ comorbid conditions
Lower BP to SBP <140 mmHg & DBP <85 mmHg
Same Rx as above
Captopril, enalapril, or quinapril ok postpartum (even if breastfeeding)
Antenatal corticosteroids for fetal lung maturity
Indication
Antenatal corticosteroids for fetal lung maturity
Administer to women w/ preeclampsia at risk of preterm birth if delivery anticipated w/in 7 days & gestational age-related criteria are met
Timing of Delivery
Severe preeclampsia
Chronic HTN
Gestational HTN
Preeclampsia
Timing of Delivery
Severe preeclampsia
Mandatory obs consult
Immediate delivery (vaginal or c-section) - regardless of gestational age (GA)
Chronic HTN
Offer initiation of delivery from 38+0 to 39+6 wks GA
Prior to 36+6 wks GA, expectant care unless indication for birth
Gestational HTN
If dx at <37+0 wks, offer initiation of delivery from 38+0 to 39+6 wks GA
If onset ≥37+0 wks GA - discuss initiation of delivery
Prior to 36+6 wks GA, expectant care unless indication for birth
Pre-eclampsia
Prior to 33+6 wks GA, consider expectant care (only in perinatal centres w/ capacity to care for very preterm infants)
Previability preeclampsia associate with ++ perinatal mortality & maternal complications –> discuss termination of pregnancy
Discuss initiation of delivery at 34+0 to 35+6 wks GA (but increased neonatal risk)
Consider initiation of delivery at 36+0 to 36+6 wks GA
Recommended to initiate delivery if ≥37+0 wks GA
Method of Delivery
Method of Delivery
Vaginal delivery considered unless c-section required for usual obstetric indications
Cervical ripening if vaginal delivery planned & cervix unfavourable
If gestational age not near term + fetal compromise: may benefit from emergency c-section
Continue anti-HTN Rx throughout L&D to keep SBP <160 mmHg & DBP<110 mmHg
Active mgt of 3rd stage w/ oxytocin
Do not use ergometrine if HDP
Anesthetic Management
Considerations
Fluids
Monitoring
Coagulation
Anesthetic Management
Inform anesthesia when pt w/ preeclampsia is admitted to delivery suite
Early epidural insertion to control labour pain (if no contraindications)
For C-section: can use epidural, spinal, CSE, or GA (if no contraindications)
No routine fixed IV fluid bolus prior to neuraxial anesthesia
Fluids
Minimize IV & po fluid intake to avoid pulm edema
No routine fluid admin to treat oliguria (<15 ml/hr x 6 hrs)
No dopamine or furosemide for persistent oliguria
Tx hTN d/t neuraxial anesthesia with phenylephrine or ephedrine
Monitoring
Art line if BP control is difficult or severe bleeding
CVP not routinely recommended
If inserted, use to monitor trends, not absolute values
PA catheter not recommended unless specific indication
Only use in ICU setting
Coagulation
Platelet (plt) count on admission to L&D
Neuraxial technique appropriate if:
Preeclampsia (w/o coagulation concerns)
Plt count ≥75
Low dose ASA & adequate plt count
UFH ≤10,000 IU/day subcut 4 hrs after last dose
?ok immediately after last dose w/o delay
UFH >10,000 IU/day subcut if normal aPTT 4 hrs after last dose
IV heparin if normal aPTT 4 hrs after last dose
LMWH 10-12 hrs after prophylactic dose or 24 hrs after therapeutic dose
Note that this reference is from the 2014 Guideline: Magee LA, Pels A, Helewa M, Rey E, von Dadelszen P; Canadian Hypertensive Disorders of Pregnancy Working Group. Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy: executive summary. J Obstet Gynaecol Can. 2014;36(5):416-441. doi:10.1016/s1701-2163(15)30588-0
MgSO4
Considerations
MgSO4
1st line tx of eclampsia
Prophylaxis against eclampsia if severe preeclampsia
Consider for prophylaxis if non-severe preeclampsia with: severe HTN, headache, visual symptoms, RUQ pain, epigastric pain, plt <100, progressive renal insufficiency, and/or elevated liver enzymes
Dose: 4g IV loading dose then 1g/hr
No routine monitoring of Mg levels
Monitor reflexes, vital signs, urine output regularly
If pre-existing or gestational HTN, consider MgSO4 for fetal neuroprotection if imminent preterm birth (w/in 24 hrs) @ ≤31+6 wks gest
Don’t delay delivery to give MgSO4 if maternal and/or fetal indications for emergency delivery
HELLP syndrome
Platelet transfusion
HELLP syndrome
Platelet transfusion
plts <20: prior to delivery
plts 20-49: prior to C-section; prior to SVD if excessive bleeding, plt dysfxn, rapidly falling plts count, coagulopathy
plts ≥50: consider if excessive bleeding, plt dysfxn, rapidly falling plts count, coagulopathy
Do not transfuse plts if strong suspicion of HIT or TTP-HUS
Postpartum
Follow up
Treatment
Acceptable agents with breastfeeding
Postpartum
Measure BP @ peak postpartum BP (3-7 days postpartum)
Evaluate women w/ postpartum HTN for preeclampsia
HTN & preeclampsia can arise de novo postpartum
Consider continuing antiHTN tx postpartum
Treat severe postpartum HTN to keep BP <160 /110 mmHg in short term
Keep BP <140/90 mmHg in long term
Anti HTN agents generally acceptable with breastfeeding:
Nifedipine XL
Labetalol
Methyldopa
Captopril, enalapril
No NSAIDs postpartum if HTN difficult to control, evidence of kidney dysfxn, or low plts
