Rebecca Wheater is a GP with an interest in cardiology and respiratory medicine; Scottish Heart and Arterial disease Risk Prevention (SHARP) Honorary Secretary; and Scottish Rugby Union Referee and International Time Keeper in her spare time, practising what she preaches by keeping active.
Pre-eclampsia, what does this mean to you? You might have come across a case when you were rotating through obstetrics during your vocational training scheme. Indeed, I have vague recollections of a magnesium drip being considered to bring a woman’s blood pressure under control. It all seemed like voodoo back then, and I must profess that my understanding of the condition has only marginally improved since.
Even the terminology has changed. Pre-eclampsia has morphed via pregnancy-induced hypertension into the latest iteration, pregnancy-associated hypertension.
“… pre-eclampsia occurs in 2%–3% of pregnancies.”
‘Placental syndrome’ includes pre-eclampsia toxaemia, pregnancy-associated hypertension, gestational hypertension, and small gestational age syndromes.
Pre-eclampsia is known to predispose women to later hypertension, ischaemic heart disease, and stroke,1 with this risk persisting beyond their childbearing years.2 Pre-eclampsia also puts women at an increased risk of diabetes.3
In placental syndrome, it is believed that there is impaired spiral remodelling of the placental blood vessels, mediated via vascular growth factors, which causes increased maternal blood pressure, endothelial dysfunction, and the placental blood vessels to be under-perfused. This is a similar mechanism to that by which angiogenic inhibitors (prescribed in renal cancer) can cause increased blood pressure. It is thought that these same inhibitors, which occur naturally, account for the vasomotor symptoms seen in menopausal women, when women start to play catch-up with men in developing cardiovascular disease.
Pregnancy is effectively a cardiovascular stress test: if the woman is healthy, all is well. If, however, the woman has subclinical cardiovascular disease, then an unhealthy ‘disease’ threshold is reached earlier than in a healthy woman. In the ongoing Poppy Study (https://www.poppyuk.net), it has been observed that total peripheral resistance increases during pre-conception, leading to pre-eclampsia, compared to those without pre-eclampsia.
As GPs we have to undertake annual audit in the name of Quality Improvement. I opted to audit pre-eclampsia. Of the four practices within my town, two do not code pre-eclampsia at all. In the other two practices, an audit was undertaken. Pre-eclampsia numbers were only a third of what was expected, given that pre-eclampsia occurs in 2%–3% of pregnancies.4
“The overarching findings showed an association between obesity and pre-eclampsia.”
The overarching findings showed an association between obesity and pre-eclampsia. In the first practice we diagnosed two new diabetics as a result of this audit. Given the endothelial dysfunction in placental vessels during pre-eclampsia, this condition may present as a continuum. After all, many consider diabetes to be a cardiovascular disease characterised by uncontrolled glucose levels.
What can we do in primary care to prevent cardiovascular complications of pre-eclampsia?
The first step is for primary care clinicians to advise future mothers to aim for optimal weight prior to conception. During pre-conception counselling, we automatically offer smoking cessation advice and signpost to folic acid supplements, yet there is an apparent reticence to encourage women with higher body mass indices (BMIs) to lose weight prior to conception, unless they seek assisted conception when weight loss is one of the criteria for referral.5 Aspirin is now advised per the National Institute for Health Care Excellence (NICE) guideline 133 (section 1.1.3) for pregnant women with a BMI ≥35 kg/m2,6 but aspirin is not a substitute for weight loss.
Pre-eclampsia needs to be correctly coded in primary care. This serves to prompt opportunistic measurement of relevant parameters (blood pressure, blood glucose, cholesterol, proteinuria, weight, and smoking status) and to highlight pre-eclampsia as a risk factor for chronic diseases (hypertension, cardiovascular disease, diabetes, and chronic kidney disease).
There is a perception that the NICE guideline 133 for hypertension in pregnancy6 is predominantly aimed at ensuring optimum health for mother and baby during pregnancy, labour, and post-partum. In section 1.10.1, the guideline mentions the risk of recurrence of hypertensive disorders of pregnancy in future pregnancies. In section 1.10.2, the guideline cites the long-term risk of cardiovascular disease following hypertension of pregnancy. In section 1.10.3, the guideline contains advice for ‘women who have had a hypertensive disorder of pregnancy to discuss how to reduce their risk of cardiovascular disease, including hypertensive disorders, with their GP or specialist.’ We cannot plead ignorance of the long-term effects of hypertension in pregnancy. We need to start joining the dots.
“… awareness raising would go a long way to helping the prevention of this far-reaching condition.”
Of concern, women do not appear to be aware of the need to attend their GP post-partum to discuss the long-term effects of hypertension of pregnancy on their ongoing cardiovascular risk. Does there need to be a public health campaign for pre-eclampsia, as there was for smoking effects in pregnancy back in the 1970s?7 In my experience, women are often their own best advocates, and awareness raising would go a long way to helping the prevention of this far-reaching condition.
Would legislation and guidance assist here? Does the NICE need to prescribe the delegation of duty for long-term follow-up of hypertension in pregnancy to primary care? In England, under section OB003 of the Quality and Outcomes Framework (QOF),8 I suggest that it should include the need to screen not only those with a BMI >27 kg/m2 from ethnic minorities, but also the need to screen women with a BMI >27 kg/m2 with a past history of hypertension of pregnancy. In Scotland, where the QOF was dissolved in 2016, the devolved government needs to find another way to encourage screening for pre-eclampsia and cardiovascular risk management in primary care.
Food for thought indeed. Rather than presenting a blanket of indifference, we need to take a preventative stance, to be mindful of these weighty matters, and to encourage healthy eating and exercise as ways of achieving weight loss pre-conception. It is not just the unconditional love of a mother for her baby at stake here; in the words of Hannah Corbin, Peloton and fitness instructor, ‘Treat your body like someone you love’. We need to wake up and smell the Roses, otherwise there is a great danger that the ship called the NHS is going to hit the iceberg of hitherto unseen cardiovascular disease.
References
1. Bellamy L, Casas J-P, Hingorani AD, Williams DJ. Pre-eclampsia and risk of cardiovascular disease and cancer in later life: systematic review and meta-analysis. BMJ 2007; 335(7627): 974.
2. Bushnell C, McCullough LD, Awad IA, et al. Guidelines for the prevention of stroke in women: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke 2014; 45(5): 1545–1588.
3. Wang Z, Wang Z, Wang L, et al. Hypertensive disorders during pregnancy and risk of type 2 diabetes in later life: a systematic review and meta-analysis. Endocrine 2017; 55(3): 809–821.
4. Royal College of Obstetricians and Gynaecologists. Pre-eclampsia. 2022. www.rcog.org.uk/for-the-public/browse-our-patient-information/pre-eclampsia (accessed 30 Aug 2024).
5. Balen AH, Anderson RA. Impact of obesity on female reproductive health: British Fertility Society, Policy and Practice Guidelines. Hum Fertil (Camb) 2007; 10(4): 195–206.
6. National Institute for Health and Care Excellence (NICE). Hypertension in pregnancy: diagnosis and management. NG133. London: NICE, 2019. https://www.nice.org.uk/guidance/ng133 (accessed 30 Aug 2024).
7. Butler NR, Goldstein H, Ross EM. Cigarette smoking in pregnancy: its influence on birth weight and perinatal mortality. Br Med J 1972; 2(5806): 127–130.
8. NHS England. Quality and Outcomes Framework guidance for 2024/25. 2024. https://www.england.nhs.uk/wp-content/uploads/2024/03/PRN01104-Quality-and-outcomes-framework-guidance-for-2024-25.pdf (accessed 30 Aug 2024).
Featured photo by Annie Spratt on Unsplash.
