I know that isotretinoin's packaging is labelled with ideograms against pregnancy, as it can cause birth defects. I'm assuming that some teratogens aren't thus labelled, as paroxetine isn't,
but according to The Hospital for Sick Children :
Selective serotonin reuptake inhibitors (SSRIs), which are used to treat depression, are capable of crossing the placenta and affecting the baby. Most of the effects in the baby are subtle, and include irritability, agitation, tremor, increased respiratory rate, nasal congestion, or diarrhea. However, the SSRI paroxetine is thought to cause birth defects in early pregnancy. [I bolded.] It is important to note that depression itself may be more harmful than the drugs used to treat depression. The benefits of SSRIs in the treatment of depression need to be weighed against the risks to the unborn baby.