Medical conditions

The impact of preexisting medical conditions on pregnancy is an extensive topic and is outlined well in Chapter 12 of your textbook. We have already discussed the impact of addictions and obesity on risk factors in pregnancy. Other medical conditions also increase the risk of complications in pregnancy. Medical conditions often interact with the changes that occur in maternal physiology in pregnancy. We will briefly discuss some common medical conditions and their effects on pregnancy. When medical conditions are present, pre-conceptual counselling is advised to optimise the mother's medical condition prior to pregnancy. 

Asthma 

• Most common chronic medical condition in pregnancy 
• Symptoms remain unchanged in 50% of women, improve in 25%, and deteriorate in 25% 
• Exacerbations of asthma are more common in the third trimester 
• Severe asthma in pregnancy increases the risk of: 
• Hospital and ICU admission 
• Preterm labour 
• SGA 
• Preeclampsia 
• Perinatal mortality 
• Women should continue their medication in pregnancy to prevent exacerbations 

Heart disease 

• Both congenital and acquired heart conditions are important to recognise prior to pregnancy to enable a pre-pregnancy consultation and risk assessment
• Some heart conditions may be so severe that pregnancy is not recommended or may be very dangerous for the mother's health (e.g. Eisenmengers syndrome) 
• Women with heart conditions are often at risk of deterioration due to the physiological changes of pregnancy and their demands on the cardiovascular system 
• Women with cardiac conditions may be at higher risk in pregnancy of: 
• Pulmonary oedema 
• Congestive heart failure 
• ICU admission 
• VTE 
• Maternal death 
• Hypoxia 
• Miscarriage 
• Compromised fetal growth 
• Preterm birth 
• Neonatal mortality 

Hypertension 

• Pre-existing hypertension is a major risk factor for the development of complications in pregnancy 
• First-line antihypertensives in non-pregnant women include ACE inhibitors, which cannot be given in pregnancy, so women need to be switched to a blood pressure medication that is safe in pregnancy either before pregnancy or as soon as they know they are pregnant  
• Pre-existing hypertension increases the risks in pregnancy of: 
• Preeclampsia 
• Placental abruption 
• SGA
• Preterm birth 

VTE 

• Pregnancy is a pro-coagulable state and women with previous VTE are at high risk for recurrent disease 
• In women without known risk factors, the rate of VTE in the antenatal period is <1% and up to 2% postpartum
• Thromboembolic disease is one of the leading causes of maternal death 
• Low molecular weight and unfractionated heparin can be used safely in pregnancy, and women can be transitioned onto warfarin after birth (safe in breastfeeding) 

Epilepsy 

• Women who have well-controlled epilepsy (stable on medication, no seizures in last year) do not usually have more seizures in pregnancy 
• However, women who have poorly controlled epilepsy are more likely to have worsening of seizures in pregnancy 
• Women should be on lower-risk anti-epileptic drugs for congenital malformations, such as lamotrigine or carbamazepine, and the aim is to use a single agent at the lowest possible dose to control seizures 
• Epilepsy increases the risk in pregnancy and post partum period of: 
• Congenital abnormalities in the fetus (this risk is present even for women who are not taking medication) 
• Epilepsy in the baby 
• Sudden death in epilepsy in the mother 
• Trauma to mother and baby with seizures 
• Labour and birth and the postpartum period are the highest risk time for seizures in pregnancy due to many factors, including hormonal changes, sleep deprivation, medications etc 

Thyroid disease 

• Most thyroid conditions are diagnosed pre-pregnancy and are being managed with medication 
• In hypothyroid women, doses of thyroxine often need to be increased as pregnancy progresses 
• When thyrotoxicosis occurs for the first time in pregnancy, it is usually a first presentation of Graves disease- propythiouracil and carbimazonle can both be used in pregnancy 
• Untreated thyroid disease can increase the risks of: 
• Miscarriage 
• Preterm birth 
• SGA
• Maternal cardiac failure and thyroid storm (hyperthyroidism) 
• Congenital hypothyroidism or hyperthyroidism 

Diabetes 

• Women with preexisting Type 1 or Type 2 diabetes have a higher risk of adverse outcomes than women with gestational diabetes 
• Glycaemic control around the time of conception and in the first trimester is crucial in determining the risk of congenital abnormalities- a preconceptual HbA1c of
• Diabetes increases risks of:
• Congenital abnormalities
• Gestational hypertension
• Preeclampsia
• PPH
• Infections in pregnancy and postpartum
• Fetal distress
• Stillbirth and neonatal death
• Shoulder dystocia
• Neonatal hypoglycaemia
• Macrosomia 

Mental health 

• Women with previous depression or anxiety are at higher risk for antenatal and postpartum depression
• Women on SSRIs or antipsychotics may need to have adjustments in their medication to safer options- however, any medication changes need to be balanced with the risk of a relapse in their mental health condition
• Women with bipolar disorder have the highest risk of mania, puerperal psychosis, and suicide
• Untreated mental health conditions have risks to the mother, but are also associated with abnormal development of the infant and child