Table 1.
Issues to be considered when a woman with an inherited disorder of metabolism plans a pregnancy.
| Pre-pregnancy |
During pregnancy and labour |
Post-partum |
|||
|---|---|---|---|---|---|
| Issue | Comment / Examples | Issue | Comment / Examples | Issue | Comment |
| Fertility | Conditions associated with premature ovarian insufficiency, e.g. Galactosemia | Metabolic control | Nausea and vomiting (‘morning sickness’) – risk factor for metabolic decompensation in any disorder of energy metabolism, e.g. FAOD, GSD, UCD, MSUD, GA1, disorders of ketone body metabolism | Metabolic control | Puerperial stress, Involution of the uterus, breastfeeding – risk period for decompensation of disorders of protein or energy metabolism |
| Risk of miscarriage | Conditions with poor metabolic control, e.g. PKU, HCU | Effects on fetus | Potential teratogenicity, e.g. maternal PKU syndrome | Contraception | Discuss if required |
| Medications | Consider possible teratogenicity, e.g. statins, ACE inhibitors, some anticonvulsants | Growth retardation (secondary to protein and / or calorie restriction or recurrent hypoglycemia) | Long-term outcome of the child | Consider follow-up for children born to mothers with rare conditions where long-term outcome remains uncertain | |
| Genetic counselling | Advice re reproductive options and options for PGD, antenatal and postnatal diagnosis | Effects on mother | Worsening of underlying condition, e.g. dyslipidemia in LPL deficiency, or secondary co-morbidities (see also Table 2) | ||
| Metabolic control | Optimise treatment, e.g. PKU, urea cycle disorders, HCU, any disorder of energy metabolism | Other maternal issues | Maternal learning difficulties, support network and financial concerns | ||
| Nutritional issues and general health | Optimisation of weight, ensure adequate vitamin and mineral supplementation in those on restricted diets | During labour and delivery | Put a plan in place to consider options for spontaneous labour, planned elective labour or need for emergency intervention. | ||
| Ensure energy requirements are met in any disorder of energy metabolism | |||||
| Muscular involvement, e.g. GSD III, mitochondrial disorders, acid maltase deficiency. Cardiac involvement, e.g. GSD III, mucopolysaccharidoses | |||||
FAOD: fatty acid oxidation disorders; GSD: glycogen storage disorders; UCD: urea cycle disorders; MSUD: maple syrup urine disease; GA1: glutaric aciduria type I; PKU: phenylketonuria; HCU: homocystinuria; LPL: lipoprotein lipase; PGD: preimplantation genetic diagnosis.