Clinical case: Pregnancy and beyond

Question 1

Why do you take the blood pressure of a pregnant woman sitting not lying?

Answer 1

Lying can cause the major blood vessels to be clamped.

Question 2

What is preeclampsia and what are the signs and symptoms?

Answer 2

It affects pregnant women after 20 weeks of gestation. New onset hypertension.
Systoli >140 and diastollic >90 mmHg.
Associated with proteinuria, which is a marker of kidney damage.

Can cause seizures (eclampsia)

Abnormal placenta. The spiral arteries do not dilate enough, which restricts blood flow t the placenta. This can lead t intrauterine growth restriction. Also causes the release of pro inflammatory proteins that enter the mothers blood causing vasoconstriction and hypertension.

Reduced blood flow to the kidney causes glomerular damage leading to proteinuria.

Ultrasound doppler uterine artery - should be low resistance and so blood should flow during diastole. In abnormal spiral arteriole, Doppler is more spiky and higher resistance so lower diastolic signal.

Question 3

What is the treatment of preeclampsia?

Answer 3

Delivery - depends on gestational age and severity

Question 4

What investigations should be done for a pregnant woman?

Answer 4

Blood pressure
Urine dipstick
Haemoglobin A1C
Ultrasound
Fetal growth
History

History:
• Age, and partner age (good)
• Mental health (psychiatric suicide risk)
• Personal medical history (anaemic)
• Obstetric history (none, G1P0, risk of preeclampsia)
• Family history (gestational diabetes, hypertension during mother’s pregnancy) (baby’s dad’s tendency for hypertension can increase risk)
• Social history (family violence screen, good support)
• Current pregnancy

Ultrasound
• Heart beating, head first, baby girl.
• Stomach visible (important for swallowing, no foregut atresia).
• Closed cervix (between head and maternal bladder).
• Amniotic fluid behind spine around baby (2-10cm fluid normal)
• Normal thick placenta (4.5cm), check abnormalities (e.g. placenta implants at cervix)

Fetal Growth
1. Measurements and graphs (customise growth chart to woman by height and weight specific, if drops during trend, problems!)
• Femur (thigh bone) length (FL)*
• Abdominal circumference (AC) (most important growth measurement)* (check foetal liver)
• Head measurement include biparietal diameter (BPD), head circumference (HC)*
2. Estimated foetal weight (calculated using *)

Fetal Wellbeing

1. Amniotic fluid volume (depth of pocket)
2. Cardiotopograph (CTG) for foetal heart rate
3. Doppler include umbilical and cerebral arteries, sometimes also venous

Placental Vasculature
If placenta has less and pathological vasculature (fibrous, little vessels with no flow in diastole), then gas/nutrient exchange compromised, thus risk of SGA, etc. (tree in summer vs winter)

Ultrasound Doppler
Doppler gives effective antenatal foetal blood flow check!
• Umbilical arterial Doppler:
o Normal foetal circulation is low resistance, diastole signal (low resistance so there is blood flow during diastole) (umbilical cord has 2 arteries and 1 vein).
o In abnormal spiral arteriole, Doppler is more spiky and higher resistance so lower diastolic signal.
o As gestation advances, placenta vessel resistance gets higher in babies with pathological lower placental vasculature, therefore diastolic signals drops, even backflow, and heart can get failure.
• Middle cerebral arterial Doppler:
o More spiky, no diastole signal, which is normal (only have diastole signal when low resistance due to baby in trouble and trying to compensate by increase brain blood flow)
o Compensatory mechanisms for SGA include brain sparing by opening up blood flow to the brain (high resistance turns to low resistance cerebral vessels). If exceed the limit, baby needs to be delivered otherwise death!