Risks of pregnancy
Pregnant narcolepsy patients will gain more weight, which puts them to a higher risk for impaired glucose metabolism and anaemia. Symptom intensity may change, in fact it is worsening in 1/3 of patients.
Pregnancy outcomes in patients with NT1 and NT2 are comparable with the general population (Maurovich-Horvat, JSR 2013; Calvo-Ferrándiz and Peraita-Adrados, 2017). As soon as patients learn that they are pregnant they should contact their physician and discuss their medication with the aim of adapting dose of medication to the pregnancy. The dose should be chosen according to the severity of symptoms and the risk of endangering oneself or the unborn. The pregnant women should immediately after learning about their pregnancy contact their specialist. So far evidence for fetal malformation risk is lacking, but there is no evidence of safety. Complete or abrupt stop of treatment is not recommended if it may cause self injury or endanger pregnancy. The benefit/risk ratio should be considered in detail. The decision must be done with the agreement (or on demand) of the fully informed patient.
Delivery
In case of frequent cataplexies, the obstetrician may recommend the caesarian section.
Puerperium and baby care
Difficulties in baby care may occur when the patient is sleepy or has cataplexies. Some patients prefer to perform baby care on the floor in order not to have the child drop from a table. Family support is needed
Inheritance of narcolepsy
The risk for the first-degree relative to develop narcolepsy type (NT1) is 1-2%. It is 10-40 fold higher than in the general population to develop excessive daytime sleepiness (EDS) 4-5%.
A patient who is already pregnant
The advices are dependent on the stage of pregnancy. Ideally therapy discontinuation is recommended (manufacturer and regulatory bodies recommendation). Special risks and periods of higher risk depend on each drug. The need for discontinuation must be fully explained to the patient. Reduction or complete stop of medication shall be decided by the patient and his/her physician depending on the estimated risks and benefits of the treatment (Thorpy and Dauvilliers 2015). The continuation of the treatment must be acknowledged by completely informed patient.
Standard obstetrician care during pregnancy
The obstetrician should be informed about narcolepsy generally and about actual symptoms intensity before the delivery and how to deal with the specific medication during delivery.
How to deal with work and social life during pregnancy?
Patients should be advised about the possibility of increased sleepiness and cataplexy, as well as other narcolepsy symptoms. In case of reduction or stopping specific medication all nonpharmacological & behavioral approaches to symptoms should be followed: scheduled naps, good sleep hygiene, avoiding situations provoking cataplexy namely at work, transportation, and in standing positions. Frequent sick leave may be needed 1. if the intensity of symptoms is increasing too much, 2. If symptoms can increase the risk of self-injury.
How to deal with delivery, breast feeding and puerperium?
In a case–control study in women with narcolepsy with cataplexy (NT1) related to pregnancy, delivery, childbirth and puerperium, data suggested that patients have pregnancy outcomes similar to healthy women. The prevalence of gestational diabetes was higher in women with narcolepsy with cataplexy. Caesarean sections, complications during delivery and the perinatal period for infants were similar in both groups. No significant differences in depression during pregnancy and during puerperium were found. Breastfeeding lasted longer in narcolepsy type 1 patients. Of note, modafinil and methylphenidate were administered during six pregnancies. (Calvo-Ferrándiz and Pêraita-Adrados, 2017).
In general, cataplexy may occur during delivery but this is rather rare. Caesarian section may be recommended in case of frequent cataplexies, the obstetrician therefore needs exact information.
Obstetric and newborn complications related to medication
• Methylphenidate or atomoxetin exposure during pregnancy was associated with low Apgar scores <10 in women with ADHD (Pauli Bro, 2015).
• Clomipramine: newborn toxicity may occur due to drug withdrawal.
• GHB abusing women can develop respiratory depression (Kuczkowski 2004).
• No evidence of increased postpartum depression
• Modafinil, methylphenidate, amphetamines, and antidepressants have no specific contraindications in nursing mothers.
• Sodium oxybate (SO) is not recommended due to its potential depressant effect in the infant. It is unknown if SO is excreted in human milk. Given its short half-life, some mothers have expressed milk before their nightly dose to give to the infant (Thorpy and Dauvilliers 2015).
• Mothers and fathers may experience difficulties with baby care due to excessive daytime sleepiness including sleep attacks during feeding or nursing, cataplexy while holding the baby and automatic behavior while nursing or travelling (Maurovich Horvat et al 2013).
Risks of malformations, and inheritance of narcolepsy
General risks during pregnancy are categorized by the Food and Drug Administration as shown in Table 1:
Table 1. Food and Drug Administration (USA), teratogenic: harms to the unborn
a. Methylphenidate: C fetal risk: Limited human data, animal data suggest moderate risk. Lactation: Limited human data – potential toxicity (namely first month)
b. Modafinil: C fetal risk: Limited human data, animal data suggest moderate risk. Avoiding the 1st trimester and period before delivery is the safest course. Inadvertent exposure during this period does not appear to represent a major risk of embryo/fetal ham. Lactation: No human data – potential toxicity.
c. SSRI, SNRI: C fetal risk: Statistically significant association with cardiovascular malformation in meta-analysis but not reaching the clinical significant level.
d. Clomipramine: C fetal risk: Human data suggest risk in 1st and 3rd trimester Lactation: Limited human data – potential toxicity
e. Sodium oxybate: C Fetal risk: No human data. Lactation: No human data.
f. (Briggs, Freemen, Yaffe. Drugs in pregnancy and lactation 2008, Thorpy et al 2013)
What can be done? Observation, registry inclusion of pregnancies……
(Modified according to J. Santamaria/Barcelona Spain and K. Sonka/Prague Czech Republic)