Hypertension Disorders in Pregnancy Irina Halfacree, October 2011

The patient DJ, 21 year old woman G1 P0 40/40 weeks Referral from Community Midwife for raised BP – 160/98 Presents to ADAU

Previous Obstetric History Booking BP – 120/74 @ 12/40 weeks BMI 23 Dating scan – normal @ 12/40 weeks Anomaly scan – normal @20/40 weeks Family History – patient’s mother – chronic hypertension, chronic kidney disease Smoker – 10/day Previous admissions to ADAU and Labour ward triage with raised BP and proteinurea

History and Examination No visual symptoms No nausea or vomiting No headache No swelling of hands or face Normal reflexes, no clonus Abdominal examination: no tenderness, SFH appropriate for stage of pregnancy, plenty of fetal movements Normal maternal pulse No fever

Differential diagnosis Essential hypertension Pregnancy-induced Hypertension Preeclampsia Eclampsia HELLP BUT normal BP at 12/40 weeks BUT it doesn’t explain the proteinurea Raised BP: systolic >140 or diastolic >90 Significant proteinurea: 2+ on dipstick PCR >30 Protein >300mg in 24h urine BUT patient asymptomatic BUT platelets and liver enzymes normal More than 300mg in 24 hour urine collection Or PCR > 30 mg/mmol

Pathogenesis of preeclampsia Summary of the pathogenesis of preeclampsia Immune factors (such as AT1-AA), oxidative stress, NK cell abnormalities, and other factors may cause placental dysfunction, which in turn leads to the release of anti-angiogenic factors (such as sFlt1 and sEng) and other inflammatory mediators to induce hypertension, proteinuria, and other complications of preeclampsia. Wang A et al. Physiology 2009;24:147-158 ©2009 by American Physiological Society

Investigations 1 Serial BP measurements: BP 138/84 → 145/86 Urine dipstick: ++ protein Urine Protein/ Creatinine ratio (PCR): 79 ↑(normal <30) Urinary protein: 0.19 ↑ (normal <0.10) Platelets: 265 (normal) Serum uric acid: 0.32 ↑ ultrasound fetal growth and amniotic fluid volume assessment • umbilical artery doppler velocimetry

Investigations 2 CTG monitoring: normal (accelerations present with fetal movement, fetal movements present, no decelerations) Ultrasound scan for fetal growth and amniotic fluid volume assessment: Abdominal circumference (AC) > 50th centile – normal Amniotic fluid index (AFI) – normal Cephalic presentation, anterior placenta Umbilical artery doppler velocimetry – end diastolic flow (EDF) – normal ultrasound fetal growth and amniotic fluid volume assessment • umbilical artery doppler velocimetry

Management Plan Induction of labour (IOL): term pregnancy, cephalic presentation, progressing preeclampsia No fetal distress and normal growth so no need for emergency caesarean section Antihypertensive treatment: Labetalol 200mg TDS

Follow-up At 40+1 /40 on (IOL) – increasing hypertension, increasing proteinurea, still asymptomatic At 40+3 /40 – spontaneous vaginal delivery of baby boy, birth weight 3.960 kg, Apgar score 9+9 1 day post-delivery BP ↓ to 124/77 so Labetalol ↓ 200mgBD Re-check BP 2 weeks post-delivery

Family history Patient’s mother obstetric history - 59 year old, P4, 2 fathers (2+2) 1st pregnancy: normal pregnancy, BW 6lb 2nd pregnancy: hypertension in last week before delivery, BW 6lb 3rd pregnancy: hypertension in last trimester and after delivery, BW 7lb 4th pregnancy: hypertension at 13 weeks (BP 200/110), IOL @ 37/40 weeks, BW 5lb Diagnosed with chronic kidney disease, on antihypertensive medication

Risk factors for pre-eclampsia First pregnancy √ First pregnancy with new partner Young mother Older mother (age 40 years or older) pregnancy interval of more than 10 years family history of pre-eclampsia (mother, sister) √ multiple pregnancy BMI of 35 kg/m2 or more gestational age at presentation previous history of pre-eclampsia or gestational hypertension pre-existing vascular disease pre-existing kidney disease

References RCOG Green Top Guidelines: The management of severe pre-eclampsia/eclampsia, 2010 NICE clinical guideline 107, Hypertension in pregnancy - The management of hypertensive disorders during pregnancy, August 2010 Impey L, Child T, Obstetrics & Gynaecology, Wiley – Blackwell, 2004 Pre-eclampsia Ante-natal Day Assessment Unit protocol Wang A et al. Physiology 2009;24:147-158, Pathogenesis of Preeclampsia

Questions True / False In normal pregnancy: Heart rate increases by 30% Stroke volume decreases by 10% Haemoglobin falls by 1g due to haemodilution Blood pressure is unchanged

Questions True / False Pregnancy induced hypertension: Is more common in primigravid women Associated with proteinuria Increased risk in smokers Occurs more frequently before 28 weeks gestation

Questions True / False Pre-eclampsia is associated with: A fall in plasma uric acid concentration Intrauterine growth restriction Disseminated intravascular coagulation Reduced blood flow to placental bed