First-trimester ultrasound and biochemical markers of XXXX and the prediction of preterm or early @entity3152 .

@entity1 @entity2007 @entity3152 @entity15714 @entity2008
OBJECTIVES: To examine the clinical utility of the first-trimester markers of @entity2007 in their ability to predict @entity3152 . METHODS: We examined 54 722 singleton pregnancies with no @entity2008 and with complete outcome data that had undergone screening for trisomy 21 by a combination of fetal nuchal translucency (NT) thickness and maternal serum free beta- @entity1 chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A ( @entity15714 ) at 11 + 0 and 13 + 6 weeks' gestation. The biochemical markers were converted to multiples of the median (MoM) of the expected normal median for a pregnancy of the same gestation and the measurements of fetal NT were expressed as the difference (delta) from the normal median NT for crown-rump length. The association between free beta-hCG, @entity15714 and delta NT and the incidence of @entity3152 before 37 weeks or early @entity3152 before 34 weeks was assessed by comparing the relative incidence at a number of MoM or delta NT cut-offs and at various centile cut-offs. At various marker levels the likelihood ratios (LR) for @entity3152 and early @entity3152 were also calculated after excluding other adverse pregnancy complications. RESULTS: The risk of @entity3152 increased with decreasing maternal serum @entity15714 . In the 3132 cases delivering before 37 weeks the @entity15714 MoM was 0.91 and in the 1060 cases delivering before 34 weeks the @entity15714 MoM was 0.90. At the 5th centile of the normal outcome group for @entity15714 (0.415 MoM) the odds ratios for delivery before 37 weeks and before 34 weeks were 1.92 and 2.35, respectively. The respective values for the 5th centile of free beta-hCG (0.41 MoM) were 1.18 and 1.08 and for the 95th centile of delta NT they were 0.91 and 0.77, respectively. CONCLUSIONS: Low levels of maternal serum @entity15714 are associated, in the absence of an abnormal karyotype, with an increased risk of preterm or early @entity3152 . The LR profiles provided at various levels of @entity15714 may be of some help in counseling @entity1 with such results and may raise awareness among healthcare professionals for increased surveillance in such cases.
