Serum müllerian-inhibiting substance in Down’s syndrome pregnancies

BACKGROUND: To examine whether maternal serum levels of müllerian-inhibiting substance (MIS) differ in Down’s syndrome and unaffected pregnancies. METHODS: Case–control study was conducted using stored serum from an antenatal screening programme. Sera from 25 Down’s syndrome pregnancies were retrieved from 2208C storage together with 125 unaffected controls individually matched for maternal age, weeks of gestation and duration of storage. Results were expressed in multiples of the gestation-specific median value (MoM) in controls. RESULTS: The median value in Down’s syndrome pregnancies was 0.83 MoM (P 5 0.77, two-tail Wilcoxon rank sum test). Among unaffected pregnancies, there was a statistically significant correlation between MIS and pregnancy-associated plasma protein-A (P < 0.05). MIS levels were elevated in pregnancies where assisted reproduction techniques had been used. CONCLUSION: There is no evidence for a substantial reduction in maternal serum MIS levels in Down’s syndrome pregnancies. This study provides useful information regarding serum MIS levels in pregnancy. Key words: antenatal screening/Down’s syndrome/marker/MIS/ovarian reserv