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A nt ihy pe r t e nsiv e dr ug s use d in pr e g na ncy

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Presentation on theme: "A nt ihy pe r t e nsiv e dr ug s use d in pr e g na ncy"— Presentation transcript:

1 A nt ihy pe r t e nsiv e dr ug s use d in pr e g na ncy
Beta-blockers Inhibit action of catecholamines on the adrenoreceptors Beta-1 affects heart rate and contractility Beta-2 affects vascular and smooth muscle Associated with neonatal hypoglycaemia and IUGR

2 Labetalol (first line treatment)
Combined alpha- and beta-blocker that can be given orally or IV Licensed for use in pregnancy. Used IV for the acute treatment of severe hypertension Avoid use with asthmatic women as it causes bronchospasm Compatible with breastfeeding

3 Methyldopa Acts centrally to produce a decrease in vascular resistance
Has a maximum effect 48 hours after commencement of treatment Small amounts are secreted into breastmilk, but it is classified as compatible with breastfeeding

4 Nifedipine Calcium channel-blocker
inhibits transport of calcium across cell membranes Causes vasodilatation, which reduces blood pressure Not licensed for pregnancy use before 20 weeks' gestation Probably compatible with breastfeeding

5

6 Compatible with breastfeeding
Hydralazine Direct-acting vasodilator No adverse fetal effects, but many maternal side effects, including acute hypotension, tachycardia and palpitations Initially 25 mg twice/day given orally in the third trimester only Compatible with breastfeeding

7 Diuretics Relieve oedema by inhibiting sodium re-absorption in the kidney and increasing urine production, thus lowering blood volume and in turn blood pressure Act within 1–2 hours of oral administration and last for 12–24 hours Usually administered in the morning so that diuresis does not interfere with sleep Loss of potassium (hypokalaemia) is a complication and potassium supplements may be given for long-term treatment of hypertension Use in pregnancy is restricted to treating complex disorders, e.g. heart disease or renal disease in combination with other drugs

8 Gestational hypertension
-Gestational hypertension is hypertension >140/90 mmHg - presents after the 20th week of pregnancy - without significant proteinuria.

9 -The BP should return to normal values postnatally.
- It can be difficult to differentiate between the presentation of chronic hypertension and gestational hypertension, because the physiological fall in BP in the first trimester of pregnancy occurs with both normotensive and hypertensive women, and can mask the existence of chronic hypertension unless pre-pregnancy values are known

10 -The diagnosis of gestational versus chronic hypertension might be resolved only in retrospect when the six-week postnatal BP readings are performed. Complications complications of gestational hypertension and chronic hypertension are the same: intrauterine fetal growth restriction (IUGR) placental abruption superimposed pre-eclampsia worsening hypertension leading to severe hypertension and risks of stroke (cerebral vascular accident [CVA] and organ damage).

11 Management The woman with known chronic hypertension should be booked at a consultant unit and re-referred to any clinics treating her hypertension and co-existing conditions. If she is taking ACE inhibitors or ARB these are discontinued and alternative hypertensive therapy prescribed The physiological fall of BP in early pregnancy might entail reducing or even ceasing antihypertensives in the first trimester, and then increasing doses gradually towards term based on BP readings.

12 The woman who has a raised BP without proteinuria presenting during pregnancy is likely to have gestational hypertension and should be referred to a maternal medicine clinic and booked for labour and birth in a consultant-led unit. -There after management of both chronic and gestational hypertension is the same and requires involvement of both doctor and midwife as follows: Schedule antenatal appointments, as for nulliparae, to see a doctor and midwife at 16, 25, 28, 31, 34, 36, 38 weeks).

13 At each appointment record BP, urinalysis with emphasis on proteinuria, and assess fetal growth by symphysis–fundal height (SFH). Be alert for signs of pre-eclampsia. Review BP readings; adjust drug dosages accordingly, aiming to keep BP <150/100 mmHg in uncomplicated cases The doctor should prescribe low-dose aspirin (75 mg once daily). Arrange ultrasound fetal growth and amniotic fluid volume assessment and umbilical artery Doppler velocimetry between 28 and 30 weeks and between 32 and 34 weeks.

14 If results are normal, these are not repeated unless there is a clinical indication .
Assess and manage co-existing conditions such as obesity or diabetes mellitus. Advise the woman to keep her dietary intake of sodium low . Hospital admission is unlikely with both chronic and gestational hypertension unless the hypertension becomes severe. Labour should be induced at 37 weeks or earlier if BP is uncontrolled, or fetal or antenatal complications develop.

15 Labour will require hourly BP monitoring and administration of hypertensive drugs with dosages adjusted if BP fluctuates. An epidural may be advantageous in labour as this lowers BP. Continuous fetal monitoring is required in labour . A normal birth by the midwife can be anticipated, and caesarean section should be performed for obstetric reasons only. The length of the second stage of labour should be shortened only if severe

16 hypertension develops.
Ergometrine and syntometrine should be avoided for the third stage of labour as these are acute vasoconstrictors. Use oxytocin in preference. Breastfeeding should be encouraged. The midwife should record BP daily in the postpartum period for the first 3 days and then on the 5th day

17 Postpartum BP should be maintained below 140/90 mmHg and, if necessary, medication adjusted.
Prior to transfer home from hospital the woman should be seen by an obstetrician who is likely to stop methyldopa within two days of birth and restart the antihypertensive treatment the woman was taking before she planned the pregnancy. If BP falls below 130/80 mmHg the obstetrician should reduce the hypertensive treatment . The midwife should reinforce advice on lifestyle factors such as diet and exercise. The combined oral contraceptive pill might be contraindicated, so referral to a doctor or family planning clinic for specialist advice is essential. The midwife should not discharge the woman from her care if BP levels give concern and other members of the multidisciplinary team may need to be involved.

18 A 2-week postnatal review with the general practitioner (GP) should be arranged where the continued use of antenatal hypertensive treatment should be reviewed. A medical review in combination with the 6-week postnatal review should also be arranged Superimposed pre-eclampsia -Women with chronic hypertension develop pre-eclampsia -signs and symptoms are the same as for pre-eclampsia -the development pre-eclampsia ,accompanied by fetal growth restriction -Management and treatment are as for pre-eclampsia

19 Secondary hypertension
Women may develop secondary hypertension as a complication of either underlying physiology or disease, most commonly caused by: Renal disease, which results in sodium retention by the kidney leading to water retention, an increased blood volume and thereafter hypertension. This may be classified as renal hypertension. Depending upon the nature of the renal disease the early birth of the baby may become necessary to prevent long-term kidney damage

20 Phaeochromocytoma, an adrenal gland tumour secreting the hormones dopamine, adrenaline and noradrenaline Congenital heart disease, especially if there is constriction of the aorta. Conn's syndrome: an excess of aldosterone hormone causes sodium retention and associated hypokalaemia. Cushing's syndrome: an excess of glucocorticoid hormones

21 Management According to the cause.
- substantive treatment wait until the woman has given birth and then treat the condition.


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