Clinical follow‐up of high mid‐trimester maternal serum intact human chorionic gonadotrophin concentrations in singleton pregnancies

Mid-trimester biochemical screening of 38 143 pregnancies in south-east Scotland revealed 127 cases (0.34 per cent) in which the maternal serum (MS) intact human chorionic gonadotrophin (hCG) concentration was > or = 4 multiples of the median in singleton pregnancies (MOM). Three were lost to follow-up but in 72 (58 per cent) complications developed or there were associated fetal abnormalities. This percentage was greatest at very high hCG concentrations, 92 per cent with hCG > or = 10 MOM (n = 12) compared with 48 per cent with hCG concentrations of 4-4.99 MOM (n=69). 22 cases had an MS alpha-fetoprotein > or = 2 MOM in addition to an MS hCG > or = 4 MOM, and in only 3 of these was the pregnancy uneventful; 86 per cent were associated with abnormalities or pregnancy complications.