Understanding Pre-Eclampsia: Physiology, Risk, and the Complex Reality of Maternity Care

 Pre-eclampsia is one of the few conditions in pregnancy where medical management — including induction of labour — is often genuinely necessary. And yet, as with many aspects of maternity care, the lived reality is not always straightforward.

Recently, a client of mine was diagnosed with pre-eclampsia at term. She was advised she needed induction. However, due to lack of beds on the labour ward, she waited three days in hospital before a space became available. She was not considered urgent enough to be prioritised — but not considered low-risk enough to go home either.

That tension raises important questions:

• When does waiting in hospital become safer than going home?

• If symptoms are mild and controlled, is spontaneous labour at home ever a reasonable option?

• At what point does the risk of escalation outweigh the risk of intervention?

Firstly, let's clarify something: pre-eclampsia is a collection of symptoms which precedes an eclamptic fit and ultimately endothelial dysfunction - which is the real issue, not the preeclampsia itself.

The endothelium is a single layer of cells that lines the interior of all blood and lymphatic vessels in the body, which controls vascular tone and plays a vital role in blood clotting and inflammation. When implantation of the placenta occurs, around 6-10 days following fertilisation, the blood vessels supplying it are remodelled to maximise the space for blood flow. In addition, maternal cells prevent the immune system from attacking the foetus. If there is abnormal remodelling, this can then lead to placental stress, which triggers systemic inflammation and endothelial dysfunction, as mentioned above.

Around 2-8% of women are affected globally by preeclampsia, of which 1% will end up with a severe case, but it occurs in around 10% of first pregnancies. As it is so well screened for, in the developed world, only 0.8-1.4% cases of preeclampsia result in an eclamptic seizure (unfortunately there are no reliable statistics in other parts of the world where it may not be diagnosed early).

It is characterised by:

• Elevated blood pressure

• Protein in the urine (proteinuria)

• Signs of organ involvement (in more significant cases)

That is why pre-eclampsia is not “just high blood pressure.” It is a multi-system condition.

It can affect:

• Kidneys – causing protein leakage into urine

• Liver – causing pain under the ribs, abnormal blood tests

• Brain – causing headaches, visual disturbance, seizures (in severe cases)

• Clotting system – affecting platelets

• Placenta – affecting baby’s growth and wellbeing

In its most serious form, it can develop into eclampsia, which involves seizures. However, not everyone with pre-eclampsia “feels” unwell — which is why routine antenatal blood pressure and urine checks matter. Symptoms can include:

• Persistent headache not relieved by usual measures

• Visual disturbances (flashing lights, blurred vision, spots)

• Pain under the right ribs or upper abdomen

• Sudden swelling of face/hands

• Nausea and vomiting (sudden onset later in pregnancy)

• Reduced foetal movements

• Blood pressure ≥140/90 mmHg

• Protein in the urine

In UK practice, a blood pressure consistently over 140/90 with proteinuria raises concern which will usually trigger the need for further testing (bloods, liver and kidney function in particular).

The only definitive cure for pre-eclampsia is birth of the placenta. That is why, particularly after 37 weeks, induction of labour is commonly recommended. How it is managed usually depends on:

• Gestational age

• Severity of blood pressure

• Blood results (liver function, platelets, kidney function)

• Symptoms

• Baby’s wellbeing

And may include:

• Antihypertensive medication

• Magnesium sulphate (if severe features are present, to prevent seizures)

• Continuous foetal monitoring in labour

• Careful fluid balance monitoring

• Blood tests at regular intervals

If induction does not progress safely, or if maternal/baby condition deteriorates, caesarean birth may become necessary.

It is important to say clearly: pre-eclampsia is one of the few situations where induction is often medically indicated and evidence-based. This is not about dismissing medical advice. It is about navigating nuance.

And this is where maternity care becomes complicated. My client’s blood pressure was raised alongside proteinuria. She absolutely met criteria for induction. She was admitted. But she was stable (with medication):

• Lower blood pressure

• No severe headache

• No visual disturbance

• Blood tests not critically abnormal

• Baby well

And then she waited. Three days and nights. 

Not urgent enough to escalate.

Not “safe” enough to go home.

This illustrates perfectly how systemic pressures intersect with clinical decision-making. If risk was truly imminent, she would have been prioritised. If risk was negligible, she might have been discharged. Being “in between” is often the hardest place to sit. My client was left feeling completely confused and really struggled to make a decision that felt right for her. Was she truly at risk? Was it urgent? 

And I get it: pre-eclampsia can escalate unpredictably. Mild disease can become severe over hours. That unpredictability is why hospitals are cautious about discharge once a diagnosis is made.

However, hospital environments also carry stress:

• Sleep deprivation

• Constant monitoring

• Anxiety

• Reduced autonomy

• Increased likelihood of cascade intervention

And we know that spontaneous labour often reduces intervention rates, and that it is unlikely to happen when you are not in your own environment. So what are your options? Legally and ethically, a pregnant person has the right to decline admission or discharge themselves.

Clinically, the questions to consider before you make this decision could be:

• What is your blood pressure trend?

• What do your bloods show?

• Are you symptomatic?

• How far along are you?

• How quickly could you return if symptoms change?

If you choose to leave hospital, robust safety planning is essential:

• Clear thresholds for returning

• Access to home BP monitoring

• Reduced foetal movement awareness

• Daily or frequent review

Pre-eclampsia is not something to ignore or minimise. It can become serious quickly. Induction in this context is often protective, appropriate and evidence-based.

And yet, families deserve:

• Clear communication about severity

• Transparent explanation of urgency

• Honest discussion of risk levels

• Shared decision-making that reflects individual presentation

If symptoms are mild and stable, conversations about monitoring, timing, and options should be nuanced — not purely protocol-driven.

Every case is individual.

Every risk profile is dynamic.

And every birthing person deserves both safety and autonomy.

If you or someone you support is navigating a diagnosis of pre-eclampsia, ask:

• What markers make this urgent?

• What would need to change for it to become urgent?

• What are my options today?

• What is the plan if I choose differently?

Informed decision-making is not anti-medical.

It is pro-safety, pro-autonomy, and pro-clarity.

And in complex cases like pre-eclampsia, clarity matters.