Approximately 4% of the adult population suffers from ADHD. Attention and executive functioning difficulties also occur in those with mood and psychotic disorders and require treatment strategies similar to those used to address ADHD symptoms. First line medications most often used to treat ADHD in adults are Dextroamphetamine (Dexedrine, Adderall) and Methylphenidate (Concerta, Ritalin, Metadate).
For women with mild to moderate ADHD symptoms, we frequently recommend discontinuing medication and switching to a non-pharmacologic intervention. On the other hand, some women have severe symptoms which may interfere with their daily functioning and may potentially affect the pregnancy. One option would be to switch to an antidepressant that may be effective for treating ADHD, such as a tricyclic antidepressant or bupropion. However, many women may not respond or tolerate these agents and may thus consider treatment with a stimulant during pregnancy to maintain their level of functioning.
Most data on Dextroamphetamine exposure in pregnancy comes from studies of drug abuse. Amphetamine or cocaine abuse is associated with low birth weight, prematurity, and increased maternal and fetal morbidity. These are likely related to placental vasoconstriction (Plessinger 1993). However, decreased birth weight was also noted in infants born to women who were prescribed Dehtroamphetamine at lower therapeutic dosages to control weight gain (Naeye 1983). If medication was continued beyond the 28th week of pregnancy, there was a 100g to 400g reduction in weight of the infants, with no change in birth length or head circumference (Naeye 1983; Golub 2005).
Methamphetamine use in pregnancy was associated with adverse maternal and neonatal outcomes (Good 2010). In a chart review including 267 women who had positive urine tests for methamphetamine compared to a control group of women with negative urine tests, the authors reported a higher risk of preterm delivery (52% vs. 17%), low Apgar scores (6% vs. 1–2%), and neonatal mortality (4% vs. 1%).
Methylphenidate abuse is associated with premature birth, growth retardation and neonatal withdrawal symptoms (Debooy 1993). Unfortunately, this study had only 38 participants, no control group and was confounded by the abuse of nicotine, alcohol and other drugs during the pregnancy.
Available data on the therapeutic use of Amphetamine in pregnancy shows no increase in the risk of congenital malformations (Milkovich 1977). A large cohort study monitoring 50,282 women with medication exposure during pregnancy (including 367 women taking Dextroamphetamine and 215 unspecified Amphetamines in the first trimester) demonstrated no increase in the risk of malformation in exposed infants (Golub 2005).
There are fewer data on the teratogenicity of Methylphenidate (Concerta, Ritalin) in pregnancy. The literature includes 69 cases studies (reviewed in Humphreys 2007), with one cardiac defect reported. However, none of the studies were statistically powered to allow for definitive conclusions regarding the reproductive safety of Methylphenidate exposure.
In conclusion, there are not enough data on use of stimulant medications in pregnancy to allow definitive conclusions about their reproductive safety. Available data for Amphetamines suggest no increase in the risk of malformation when used at therapeutic doses, while infants might have slightly lower birth weights. Human data on Methylphenidate is limited and we cannot rule out the risk of malformation given the available information. Alternative pharmacologic treatment options include tricyclic antidepressants, bupropion and clonidine; these drugs have more evidence to support their safety in pregnancy.
Snezana Milanovic, MD, MSc