Table 3.

Recommended management options for treating hypertension in pregnancy

Drug Treatment	Dose[26, 27]	FDA Class	Safety	Side Effects	Breast feeding*
First line agents
Methyldopa (F), (I–A) Drug of choice according to all groups	0.5–3 gm/day in 2divided doses	B	Proven safety and efficacy	Some concern with depression, hepatic disturbances, hemolytic anemia -may not lower BP adequately	Compatible with breast milk
Labetalol (M), (I–A)	200–1200 mg/day p.o. in 2–3 divided doses 20–40mg iv (max 220mg total)	C	Safety similar to methyldopa may be more efficacious than methyldopa;	May be associated with fetal growth restriction. Neonatal hypoglycemia with larger doses	Usually compatible with breast milk
Second-line agents
Nifedipine Long-acting (Ra), (I–A)	10–30 mg p.o.	C	widely used	May inhibit labor; Rarely, profound hypotension if short- acting agent is used with magnesium	Usually compatible with breast milk
Verapamil	80mg tds p.o.	C	Similar efficacy to other oral agents	Risk of interaction with magnesium – bradycardia	Usually compatible with breast milk
Clonidine Alternative option	0.1–0.6 mg/day in 2 divided doses	C	Safety similar to methyldopa Limited data regarding fetal safety	Efficacy similar to methyldopa	Possible breast milk effects
Hydrochlorothiazide Useful in chronic hypertension	12.5–25 mg/day	B		Volume contraction, electrolyte abnormalities – rare with small doses	May reduce breast milk production
Hydralazine (F, Re) Not recommended by ESH [24, 23]	50–300 mg/d in 2–4 divided doses	D	Efficacious intraveno us agent	Possible maternal polyneuropathy, drug-induced lupus, neonatal lupus and thrombocytopenia; Tachyphylaxis	Usually compatible with breast milk
Atenolol	(Atenolol not recommended) (I–D) Atenolol has risk of growth restriction when started in first or second trimester and is not recommended if breast feeding
Diazoxide	30–50 mg iv every 5–15 min; iv bolus for acute BP lowering in severe hypertension [19]
Prazosin	0.5–5mg tds; consider as a second line agent by SOMANZ [19] Not recommended by SOGC[16] (I–D) Associated with postural hypotension and palpitations
Oxprenolol (beta blocker with ISA)	20–160mg tds; a first line agent by SOMANZ[19] Contraindicated in heart block
Nitroprusside	Only considered for life-threatening severe hypertension Cyanide and thiocyanate toxicity, must be carefully monitored. Also risk of cardio-neurogenic syncope
Contraindicated[26]	ACE inhibitors, angiotensin II receptor blockers (Pr, Re), (II-2E), FDA Class D
	Direct renin inhibitors
	Spironolactone not recommended due to potential foetal antiandrogen effects
Other Management Strategies
Low dose aspirin	Use advised in women at high risk Used prophylactically in women with a history of preeclampsia at <28 Weeks
Fish oil supplementation	Not recommended
Calcium supplementation	May have role in decreasing incidence of preeclampsia Role in low calcium intake populations
Vitamin C and E	Not recommended
Steroid therapy	Only for fetal lung maturation

^*According to either the World Health Organization and/or Thomson lactation ratings. FDA, Food and Drug Administration; ISA, intrinsic sympathomimetic activity. The abbreviations in parentheses represent the types of studies that provided the evidence base for the recommendations from the NHBPEP. (M)- meta-analysis, an analysis of a compendium of experimental studies; (Ra)- randomized controlled trials; (Re)- retrospective analyses, also known as case-control studies; (F)- prospective follow-up, also known as cohort studies, including historical cohort studies and long-term follow-up; (Pr)- previous review or position statements; and the key codes from the evidence base used by the SOGC. An explanation of these can be found in the appendices.