Pre-existing Conditions in Pregnancy

Having chronic diseases and taking medication can increase the risk of harm to the mother and the fetus.

Diabetes Mellitus in Pregnant Women

Like gestational diabetes, uncontrolled diabetes is dangerous in pregnant woman

– This is because the placenta secretes cortisol and progesterone which increases insulin resistance

– This leads to complications for the mother as well as for the fetus.

– Babies can be large (or small) for gestational age (macrosomia) which can make delivery difficult

– In addition, there is a higher risk of the baby being born with hypoglycaemia, jaundice and polycythaemia

Management:

This involves managing the hyperglycaemia and taking steps to manage potential complications

Hyperglycaemia:

– Stop oral antidiabetic medication except metformin and start taking insulin

– Monitor complications of diabetes such as retinopathy

Managing complications:

– NTDs –> Take higher dose of folate supplements 5mg/day from pre-conception to 12 weeks’ gestation

– Pre-eclampsia –> Take aspirin 75mg daily from 12 weeks to delivery

– Heart defects –> At the anomaly, use ultrasound to check heart in detail to scan for potential abnormalities

Hypertension in Pregnant Women

This is defined as having a history of hypertension (blood pressure of >140/90mmHg) before 20 weeks of gestation (without proteinuria or oedema).

– Normally, blood pressure should fall in the first trimester, and so women should not be hypertensive

– Whilst pre-existing hypertension is asymptomatic, the problem is that it is a risk factor for the development of complications like pre-eclampsia and HELLP syndrome, and so needs to be managed cautiously

Management:

This involves controlling the BP and taking steps to manage potential complications

Blood pressure:

– Stop unsafe drugs (ACEi, ARBs, thiazide diuretics

– Switch to pregnancy-suitable drugs –> 1st line is labetalol, 2nd line nifedipine, 3rd methyldopa

Complications:

– Pre-eclampsia –>  Take aspirin 75mg daily from 12 weeks

Epilepsy in Pregnant Women

Anti-epileptic medication can increase the risk of congenital defects. However, the evidence shows that it is safer to treat the mother as uncontrolled epilepsy in pregnancy can be fatal.

– However, it is important to know that several of the antiepileptics have teratogenic effects 

Management

This involves controlling the epilepsy and taking steps to manage potential complications

Epilepsy:

– Do not use sodium valproate unless necessary

– Ideally switch to lamotrigine or carbamazepine

Complications:

– NTDs –>  Take higher dose of folate supplements 5mg/day from pre-conception to 12 weeks’ gestation

Rheumatoid arthritis in Pregnant Women

A lot of women with rheumatoid arthritis notice an improvement in their symptoms during pregnancy

– This is the because the hormonal changes cause a dampening down of the immune system

– However, many women might experience a flare up after giving birth as the immune system rebounds

– In addition, many of the immunosuppressants are teratogenic, so you need to exercise caution.

Management:

– Methotrexate needs to be stopped 6 months before pregnancy for both man and woman. This is because it reduces synthesis of folic acid which leads to neural tube defects

– Sulfasalazine, Hydroxychloroquine and low dose steroids are usually safe to use