Infants born to pregnant women treated with antipsychotics may exhibit extrapyramidal and other symptoms including agitation, increased or decreased muscle tone, tremor, sleepiness, respiratory difficulties, and feeding problems. Infants prenatally exposed to antipsychotics showed significantly lower neuromotor development scores than those with no psychotropic exposure ( Johnson et al. 2012 ). The neuromotor scores were also significantly associated with maternal psychiatric history, including depression, psychosis, and overall severity/chronicity, which again illustrates the difficulty separating the impact of medication from the underlying psychotic disorder.
Haloperidol is a typical butyrophenone type antipsychotic that exhibits high affinity dopamine D 2 receptor antagonism and slow receptor dissociation kinetics.  It has effects similar to the phenothiazines .  The drug binds preferentially to D 2 and α 1 receptors at low dose (ED 50 = and mg/kg, respectively), and 5-HT 2 receptors at a higher dose (ED 50 = mg/kg). Given that antagonism of D 2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT 2 receptors on the negative symptoms, this characteristic underlies haloperidol's greater effect on delusions, hallucinations and other manifestations of psychosis.  Haloperidol's negligible affinity for histamine H 1 receptors and muscarinic M 1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic hypotension though having higher rates of treatment emergent extrapyramidal symptoms .