From the Guidelines
Women with pre-existing medical conditions should be managed with a multidisciplinary approach before, during, and after pregnancy to minimize risks and ensure optimal outcomes for both mother and fetus. This approach involves obstetricians, maternal-fetal medicine specialists, and relevant specialists for the specific condition. Common pre-existing conditions that pose risks include diabetes, hypertension, cardiac disease, thyroid disorders, epilepsy, autoimmune diseases, and mental health conditions.
Key Considerations
- For diabetic women, tight glycemic control is essential with target HbA1c below 6.5% if possible, using insulin as the primary medication, as noted in the management of diabetes in pregnancy standards 1.
- Women with hypertension often require medication adjustments, with labetalol, nifedipine, and methyldopa being preferred options while ACE inhibitors and ARBs must be discontinued due to fetal risks, as highlighted in guidelines on managing cardiovascular diseases during pregnancy 1.
- Cardiac conditions require careful monitoring with medication adjustments and sometimes activity restrictions, with recommendations for pre-pregnancy risk assessment and counseling, as outlined in ESC guidelines on the management of cardiovascular diseases during pregnancy 1.
- Thyroid disorders need close monitoring with levothyroxine dose increases of 25-50% common during pregnancy.
- For epilepsy, lamotrigine and levetiracetam are generally preferred over valproate, which carries significant teratogenic risks.
- Autoimmune conditions like lupus or rheumatoid arthritis may flare during pregnancy, requiring medications like hydroxychloroquine, low-dose corticosteroids, or certain TNF inhibitors that are considered relatively safe.
Management Strategies
- Regular monitoring, including more frequent prenatal visits, specialized ultrasounds, and laboratory testing, is essential for all these conditions to ensure maternal health and optimal fetal development.
- Preconception care should include risk assessment, health promotion, and interventions to address identified risks, as recommended in guidelines for preconception care 1.
- Counseling women at increased risk of maternal morbidity and mortality should be a continuous process throughout the reproductive life course, providing accurate, comprehensible, evidence-based information about the risks and treatment alternatives, as emphasized in the Society for Maternal-Fetal Medicine consult series 1.
From the FDA Drug Label
Warfarin sodium tablets are contraindicated in women who are or may become pregnant because the drug passes through the placental barrier and may cause fatal hemorrhage to the fetus in utero. Furthermore, there have been reports of birth malformations in children born to mothers who have been treated with warfarin during pregnancy. Embryopathy characterized by nasal hypoplasia with or without stippled epiphyses (chondrodysplasia punctata) has been reported in pregnant women exposed to warfarin during the first trimester Central nervous system abnormalities also have been reported, including dorsal midline dysplasia characterized by agenesis of the corpus callosum, Dandy-Walker malformation, and midline cerebellar atrophy. Ventral midline dysplasia, characterized by optic atrophy, and eye abnormalities have been observed Mental retardation, blindness, and other central nervous system abnormalities have been reported in association with second and third trimester exposure Although rare, teratogenic reports following in utero exposure to warfarin include urinary tract anomalies such as single kidney, asplenia, anencephaly, spina bifida, cranial nerve palsy, hydrocephalus, cardiac defects and congenital heart disease, polydactyly, deformities of toes, diaphragmatic hernia, corneal leukoma, cleft palate, cleft lip, schizencephaly, and microcephaly Spontaneous abortion and stillbirth are known to occur and a higher risk of fetal mortality is associated with the use of warfarin. Low birth weight and growth retardation have also been reported.
The risks associated with warfarin use during pregnancy include:
- Fatal hemorrhage to the fetus
- Birth malformations
- Embryopathy
- Central nervous system abnormalities
- Mental retardation
- Blindness
- Teratogenic effects
- Spontaneous abortion
- Stillbirth
- Fetal mortality
- Low birth weight
- Growth retardation
Management strategies for women with pre-existing medical conditions during pregnancy who are taking warfarin include:
- Careful evaluation and critical review of indications for anticoagulant therapy
- Discussion of potential risks to the fetus and possibility of termination of pregnancy
- Close monitoring of prothrombin time tests and regular visits to physician or clinic
- Avoidance of activities or sports that may result in traumatic injury
- Maintenance of a consistent diet and avoidance of drastic changes in dietary habits
- Notification of physician immediately if any unusual bleeding or symptoms occur 2 2
From the Research
Risks in Pregnancy
- Women with pre-existing medical conditions during pregnancy face various risks, including preeclampsia, preterm delivery, and small for gestational age infants 3
- The risk of small for gestational age infants is lower with methyldopa than labetalol, suggesting that methyldopa may be a preferable antihypertensive medication in pregnancy 3
- Nutritional counseling and interventions are crucial to reduce the risk of maternal, fetal, and neonatal complications, as well as short- and long-term adverse outcomes 4
Management Strategies
- Regular physical exercise during pregnancy is associated with numerous benefits, including preventing gestational diabetes, excessive gestational weight gain, and hypertensive disorders 5
- Exercise is not related to an increased risk of maternal or perinatal adverse outcomes, and compliance with current guidelines is sufficient to achieve the main benefits 5
- Exercise type and intensity should be based on a woman's previous fitness level, medical history, and characteristics of the ongoing pregnancy 5
- Appropriate exercises and precautions can minimize the potential risks of exercise during pregnancy, including hypoxia, hyperthermia, and abnormal heart rate changes 6
Pre-Existing Medical Conditions
- Women with chronic hypertension should be treated with antihypertensive medications, such as methyldopa or labetalol, to minimize the risk of complications 3
- Women with pre-existing medical conditions should receive individualized care and management strategies to optimize outcomes 7
- A healthy diet and regular physical exercise can help reduce the risk of complications and improve outcomes for women with pre-existing medical conditions during pregnancy 4, 5