Objective Women who conceive while taking antidepressants frequently have anxieties about the possible effect on their baby. These women may stop taking the antidepressants with or without preconception counselling. We aim to show what effects this may have on their depression and pregnancy.

Method We present a prospective study of 36 women in a specialist perinatal mental health antenatal clinic. Women were divided into two broad groups: those who reduced or discontinued their medication and those who maintained, increased or switched to another medication.

Results There was no significant association with age, parity or marital status.

Six different antidepressants were encountered: fluoxetine, citalopram, paroxetine, sertraline, mirtazepine and desipramine in order of frequency of use.

21/36 (58%) either decreased or discontinued their medication. 13/36 (36%) had preconception counselling mostly via their general practitioner. Of those who had preconception counselling, 10 (77%) decreased or stopped their medication.

13/36 patients reported a relapse of depression in pregnancy of whom 85% had either stopped or reduced their medication. 11/21 (52%) of those who stopped medication relapsed compared with 2/15 (13.3%) of those who stayed on medication, a 4-fold increase. 82% went back on their medication.

Conclusions Preconception counselling needs to be balanced to ensure women are aware of the 4-fold increased risk of depression relapse if they stop their medication.