Case: A 32 year old with known classical 21 hydroxylase deficiency was planning her first pregnancy. She had a history of clitoral reduction and vaginal reconstructive surgery as a baby. Pre-conception control on prednisone and fludrocortisone was good: 17(OH) progesterone 8.3 nmol/l, androstenedione 9.8 nmol/l (0.710.8), testosterone 3.0 nmol/l (0.23). EUA showed a small vaginal opening and she was given vaginal dilators. She conceived successfully and was counselled about the potential virilising effects on a female foetus. She declined amniocentesis, but a detailed scan suggested a male foetus. Throughout pregnancy growth scans were appropriate. In the 3rd trimester, vaginal examination revealed a narrow canal, and the possibility of caesarean section was discussed. At 29 weeks she was admitted with a chest infection, treated with antibiotics and IV hydrocortisone, making a good recovery. The obstetric anaesthetics and neonatologists were informed about her with a plan for increased steroids at delivery. At 36 weeks she presented after missing a routine scan and was found to have intrauterine foetal death. Chorionic villous biopsy was performed and she had caesarean delivery of a growth restricted stillborn male.
Discussion: Classical CAH in pregnancy may have serious complications. Maternal complications include increased risk of miscarriage, pre-eclampsia, gestational diabetes mellitus and caesarean section. The foetus is at risk of growth restriction and, if female, virilising effects. Exogenous steroids used to treat CAH are safe in pregnancy because they are inactivated by placental 11-BHSD, protecting the foetus against adrenal suppression. The literature is sparse on outcomes of pregnancy in women with CAH due to low fertility rates. This is attributed to amenorrhea, anovulation, polycystic ovarian syndrome and psychosexual problems following corrective surgery. Management requires increased surveillance and a multidisciplinary approach to ensure best outcomes for mother and baby.