What you have been diagnosed with

NICE guideline NG133 defines gestational hypertension as "new hypertension presenting after 20 weeks of pregnancy without significant proteinuria". Hypertension itself is defined as "blood pressure of 140 mmHg systolic or higher, or 90 mmHg diastolic or higher", and severe hypertension as "over 160 mmHg systolic or over 110 mmHg diastolic".

The NHS puts the same boundaries in plainer terms: "Hypertension in pregnancy is defined as having a blood pressure reading between 140/90 and 159/109 mmHg", and "severe hypertension in pregnancy is defined as having a blood pressure reading of 160/110 mmHg or higher. This will require treatment until the reading is below 160/110 mmHg."

ACOG's definition is compatible: gestational hypertension is systolic 140 mmHg or higher and/or diastolic 90 mmHg or higher, first happening after 20 weeks, in someone who had normal blood pressure before pregnancy.

The word doing the work is without. If protein appears in your urine, or your bloods change, or your baby's growth falters, the diagnosis becomes pre-eclampsia and the care plan changes with it. Gestational hypertension is therefore monitored as much for what it might become as for what it is.

The first appointment after diagnosis

NICE recommendation 1.4.1 says a full assessment "should be carried out in a secondary care setting by a healthcare professional who is trained in the management of hypertensive disorders of pregnancy". This is not a GP-only condition. The NHS describes the same route: if you are found to have high blood pressure in pregnancy, "you will be assessed in a hospital by a healthcare professional, usually a midwife".

Recommendation 1.4.2 lists the features that mean you need extra assessment and follow-up: nulliparity, age 40 or older, a pregnancy interval of more than 10 years, family history of pre-eclampsia, multi-fetal pregnancy, BMI of 35 kg/m2 or more, gestational age at presentation, previous pre-eclampsia or gestational hypertension, pre-existing vascular disease and pre-existing kidney disease.

Your monitoring schedule

NG133 table 1 sets it out precisely. If your blood pressure is between 140/90 and 159/109 mmHg:

Admission: "Do not routinely admit to hospital."
Blood pressure: measured once or twice a week, depending on the readings, until it is 135/85 mmHg or less.
Dipstick proteinuria: once or twice a week, taken with the blood pressure.
Bloods: full blood count, liver function and renal function at presentation and then weekly.
Baby: fetal heart auscultation at every appointment; ultrasound assessment at diagnosis and, if normal, repeated every 2 to 4 weeks if clinically indicated; CTG only if clinically indicated.

If your blood pressure reaches severe levels you are admitted, readings are taken every 15 to 30 minutes until it is below 160/110 mmHg, proteinuria is checked daily, and scans are repeated every 2 weeks if severe hypertension persists.

Treatment thresholds

Pharmacological treatment is offered "if BP remains above 140/90 mmHg", and to everyone with severe hypertension. The target once you are on treatment is "BP of 135/85 mmHg or less".

Labetalol is the first choice, nifedipine where labetalol is unsuitable, and methyldopa if neither is (recommendation 1.4.5). Two things NICE explicitly rules out: bed rest in hospital as a treatment for gestational hypertension (1.4.6), and salt restriction as a way of preventing hypertensive disorders (1.1.6).

The PlGF test

Recommendation 1.4.4 asks for placental growth factor-based testing "on 1 occasion" if pre-eclampsia is suspected - and gestational hypertension is the example NICE gives - between 20 weeks and 36 weeks plus 6 days of pregnancy. It is designed to help rule pre-eclampsia out. A normal result is reassurance about the next few weeks; it is not a licence to skip appointments.

Aspirin: prevention, not treatment

Aspirin appears in this guideline as prophylaxis, taken from 12 weeks, not as something started once hypertension has already been diagnosed. NICE recommends 75 mg to 150 mg daily from 12 weeks until the birth for women at high risk, which includes chronic hypertension and hypertensive disease in a previous pregnancy, and the same dose for anyone with more than one moderate risk factor (nulliparity, age 40 or older, pregnancy interval over 10 years, BMI of 35 kg/m2 or more at first visit, family history of pre-eclampsia, multi-fetal pregnancy).

If you are already past 12 weeks when gestational hypertension is diagnosed, ask - but do not assume aspirin is part of the plan. NICE also lists things not to use for prevention: nitric oxide donors, progesterone, diuretics, low molecular weight heparin, and, taken solely for this purpose, magnesium, folic acid, vitamins C and E, fish or algal oils and garlic.

Timing of birth

Recommendation 1.4.7: "Do not offer planned early birth before 37 weeks to women with gestational hypertension whose blood pressure is lower than 160/110 mmHg, unless there are other medical indications." After 37 weeks, recommendation 1.4.8 says timing of birth "should be agreed between the woman and the senior obstetrician". That is a genuine conversation rather than a fixed date, and it is reasonable to ask what is driving the recommendation you are given.

If early birth does become necessary, a course of antenatal corticosteroids and magnesium sulfate are offered where indicated.

After the birth

Blood pressure does not always settle immediately. NICE asks for readings daily for the first two days, at least once between day 3 and day 5, and as clinically indicated if treatment changes. If you were not on treatment and your blood pressure reaches 150/100 mmHg or higher, treatment is started. If you were on treatment, it is reduced once blood pressure falls below 130/80 mmHg. Methyldopa is stopped within two days of the birth and swapped for something else if needed.

You should be given a written care plan before transfer to community care, a medical review two weeks after transfer if you are still on treatment, and a review with your GP or specialist 6 to 8 weeks after the birth. ACOG notes the reason to keep that last appointment: gestational hypertension "may increase the risk of developing high blood pressure in the future".

Gestational Hypertension