First trimester maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein A in pregnancies complicated by diabetes mellitus.

To investigate whether markers of first trimester screening for aneuploidies, including fetal nuchal translucency (NT), maternal serum free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein A (PAPP-A), are altered in women with pre-existing type-1 and type-2 diabetes mellitus, and in women that subsequently develop gestational diabetes mellitus (GDM). Retrospective analysis of prospective combined screening for aneuploidies in singleton pregnancies at 11(+0) -13(+6) weeks of gestation. Antenatal clinic. Singleton pregnancies at 11(+0) -13(+6) weeks of gestation resulting in the delivery of phenotypically normal neonates. The study included 194 women with type-1 diabetes, 122 women with type-2 diabetes, 779 women who developed GDM and 41,007 non-diabetic controls. Maternal free β-hCG and PAPP-A levels were expressed as multiples of the respective normal median (MoM), and fetal NT was expressed as a difference from the expected median (Δ). Comparison of median MoM maternal free β-hCG and PAPP-A, and fetal NT, in the four outcome groups. There were no significant differences between the groups in median ΔNT and maternal free β-hCG MoM. Maternal median PAPP-A in type-2 diabetes, compared with the non-diabetic group, was reduced (0.75 MoM, IQR 0.50-1.09 MoM versus 1.00 MoM, IQR 0.68-1.42 MoM; P < 0.001), which resulted in doubling in the false-positive rate in the combined screening in this population. There were no significant differences in maternal PAPP-A between the other groups. In women with type-2 diabetes, the estimation of accurate patient-specific risk in the first trimester combined screening for aneuploidies necessitates an adjustment of maternal serum PAPP-A.

Savvidou MD ，Syngelaki A ，Muhaisen M ，Emelyanenko E ，Nicolaides KH ... -  《-》

Maternal serum free-beta-chorionic gonadotrophin, pregnancy-associated plasma protein-A and fetal nuchal translucency thickness at 10-13(+6) weeks in relation to co-variables in pregnant Saudi women.

To establish normative values and distribution parameters of first-trimester screening markers, namely, fetal nuchal translucency (NT), maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A), at 10 to 13(+6) weeks of gestation in Saudi women and to evaluate the effect of co-variables including maternal body weight, gravidity, parity, fetal gender, twin pregnancy, smoking and ethnicity on these markers. A cohort of Saudi women (first cohort n = 1616) with singleton pregnancies prospectively participated in the present study, and fetal NT together with maternal serum free beta-hCG and PAPP-A were determined at 10 to 13(+6) weeks of gestation. The distribution of gestational age-independent multiples of the median (MoM) of the parameters was defined and normative values were established, and correction for maternal body weight was made accordingly. The influence of various co-variables was examined using the data collected from the first and the second (n = 1849) cohorts of women and 62 twin pregnancies, and compared with other studies. All markers exhibited log-normally distributed MoMs. Gestational age-independent normative values were established. Maternal body weight was corrected, particularly for maternal free beta-hCG and PAPP-A using standard methods. Fetal NT showed a negative relationship with increasing gravidity (r = -0.296) or parity (r = -0.311), whereas both free beta-hCG and PAPP-A exhibited a significant positive relationship. There was a significant increase in the MoM of free beta-hCG in female fetuses. Smoking decreased MoM values of free beta-hCG (by 14.6%; P < 0.01) and PAPP-A (by 18.8%; P < 0.001). Twin pregnancy showed significant increases in MoM values of free beta-hCG (by 1.87-fold) and PAPP-A (by 2.24-fold), with no significant changes in fetal NT MoM values. Fetal NT MoM values were lower in Africans and Asians but higher in Orientals, as compared to Saudi women (P < 0.05; in each case). MoM values (body weight-corrected) of free beta-hCG were 25.2% higher in Africans and 19.4% higher in Orientals but 6.8% lower in other Arabian and Asian (by 5.8%) women as compared to Saudi women (P < 0.05; in each case). The normative values and distribution parameters for fetal NT, maternal serum free beta-hCG and PAPP-A were established in Saudi singleton pregnancies, the maternal body weight together with smoking, twin pregnancy and ethnicity being important first-trimester screening co-variables. Gravidity, parity and fetal gender are also considered to influence one or more of the first-trimester markers examined.

Ardawi MS ，Nasrat HA ，Rouzi AA ，Qari MH ，Al-Qahtani MH ，Abuzenadah AM ... -  《PRENATAL DIAGNOSIS》

Screening for trisomy 21 by fetal tricuspid regurgitation, nuchal translucency and maternal serum free beta-hCG and PAPP-A at 11 + 0 to 13 + 6 weeks.

To examine whether in pregnancies with fetal trisomy 21 the level of maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 to 13 + 6 weeks' gestation is independent of the presence or absence of tricuspid regurgitation and to estimate the performance of a screening test that combines tricuspid regurgitation with fetal nuchal translucency (NT) thickness and serum free beta-hCG and PAPP-A. The study population comprised 77 trisomy 21 and 232 chromosomally normal fetuses from singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation. In all cases the fetal karyotype was determined by chorionic villus sampling (CVS), which was carried out at the request of the parents after first-trimester screening for trisomy 21 by fetal NT and maternal serum free beta-hCG and PAPP-A. Immediately before chorionic villus sampling, fetal echocardiography was performed and the presence or absence of tricuspid regurgitation was determined by pulsed wave Doppler ultrasonography. The distribution of fetal NT, maternal serum free beta-hCG and PAPP-A in trisomy 21 fetuses with absent and present tricuspid regurgitation was examined. We examined two screening strategies: first, integrated first-trimester screening in all patients and second, first-stage screening of all patients using fetal NT and maternal serum free beta-hCG and PAPP-A followed by second-stage assessment of tricuspid regurgitation only in those with an intermediate risk of 1 in 101 to 1 in 1000 after the first stage. Tricuspid regurgitation was observed in 57 (74.0%) of the trisomy 21 fetuses and in 16 (6.9%) of the chromosomally normal fetuses. There were no significant differences in median maternal age, median gestational age, free beta-hCG multiples of the median (MoM) and PAPP-A MoM in trisomy 21 fetuses with and without tricuspid regurgitation. The modeled detection rates of trisomy 21 for fixed false positive rates of 1%, 2% and 5% in screening by maternal age, fetal NT thickness and maternal serum free beta-hCG and PAPP-A and assessment of tricuspid flow in all cases were 87%, 90% and 95%. In the two-stage approach, the estimated detection rate was 91% and the false positive rate was 2.6%. There is no relationship between tricuspid regurgitation and the levels of maternal serum free beta-hCG and PAPP-A in cases with trisomy 21. An integrated sonographic and biochemical test at 11 + 0 to 13 + 6 weeks can potentially identify about 90% of trisomy 21 fetuses for a false-positive rate of 2-3%.

Falcon O ，Auer M ，Gerovassili A ，Spencer K ，Nicolaides KH ... -  《ULTRASOUND IN OBSTETRICS & GYNECOLOGY》

Prospective validation of first-trimester combined screening for trisomy 21.

To examine the performance of the new algorithm in screening for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A). This was a prospective screening study for trisomy 21 in singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation using an algorithm combining maternal age, fetal NT thickness based on the mixture model for the assessment of NT, and maternal serum free beta-hCG and PAPP-A based on a multiple regression model for the assessment of serum biochemistry. The NT measurements were performed by 60 operators who had obtained The Fetal Medicine Foundation certificate of competence in the 11-13-week scan. The study population consisted of 19 614 pregnancies with a normal karyotype or delivery of a phenotypically normal baby (euploid group) and 122 cases of trisomy 21. In the euploid fetuses the NT was above the previously defined 50(th), 95(th) and 99(th) centiles in 10 033 (51.2%), 618 (3.2%) and 123 (0.6%) cases and the respective values for trisomy 21 were 117 (95.9%), 94 (77.0%) and 57 (46.7%). The median fetal NT was within 0.1 mm of the expected in 47 (78.3%) of the 60 sonographers and within 0.2 mm in all. In the euploid fetuses the median free beta-hCG was 1.0 (range, 0.1-29.4) multiples of the median (MoM) and the median PAPP-A was 1.0 (range, 0.2-3.3) MoM. The median MoM values were 1.0 or close to 1.0 MoM for each subgroup of pregnancy characteristics, including gestations of 11, 12 and 13 weeks, maternal weight of < 60 kg, 60-80 kg and > 80 kg, different ethnic origins, cigarette smokers and non-smokers, natural conception and in vitro fertilization. For a false-positive rate of 3%, the detection rate of trisomy 21 in screening by maternal age and fetal NT was 81% (95% CI, 73-89%), by maternal age and maternal serum biochemistry it was 63% (95% CI, 56-72%) and by combined screening based on maternal age, fetal NT and maternal serum biochemistry it was 90% (95% CI, 84-96%). This study has validated the new risk algorithm and demonstrated that in combined screening for trisomy 21 based on maternal age, fetal NT and free beta-hCG and PAPP-A the detection rate is about 90% for a 3% false-positive rate.

Kagan KO ，Etchegaray A ，Zhou Y ，Wright D ，Nicolaides KH ... -  《-》

First-trimester ultrasound and biochemical markers of aneuploidy and the prediction of impending fetal death.

To examine the clinical utility of the first-trimester markers of aneuploidy in their ability to predict future fetal loss. We examined 54,722 singleton pregnancies with no chromosomal abnormality and with complete outcome data that had undergone screening for trisomy 21 by a combination of fetal nuchal translucency (NT) thickness, maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 and 13 + 6 weeks' gestation. The biochemical markers were converted to multiples of the expected normal median for a pregnancy of the same gestation (MoM) and the measurements of fetal NT were expressed as the difference (delta) from the normal median NT for crown-rump length (CRL). The association between free beta-hCG, PAPP-A and delta NT and the incidence of fetal loss prior to 24 weeks, at or after 24 weeks or at any time, 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 ratio (LR) for fetal loss was also calculated. The rate of fetal loss increased with decreasing maternal serum free beta-hCG and PAPP-A and increasing delta NT. At the 5th centile of the normal outcome group for free beta-hCG (0.41 MoM) the odds ratio for fetal loss before 24 weeks, at or above 24 weeks and at any gestation was 3.1, 1.8 and 2.6, respectively. The respective values for the 5th centile of PAPP-A (0.415 MoM) were 3.3, 1.9 and 2.8 and for the 95th centile of delta NT they were 2.5, 1.9 and 2.2, respectively. There was almost no correlation between reduced levels (<or=0.50 MoM) of PAPP-A and reduced levels of free beta-hCG in either the normal pregnancy group (r = 0.041) or the group with fetal death (r = 0.072), indicating relatively independent prediction by either biochemical marker. Low levels of maternal serum PAPP-A and free beta-hCG and increased fetal NT are associated, in the absence of an abnormal karyotype, with an increased risk of impending fetal death. The likelihood ratio profiles provided at various levels of PAPP-A or free beta-hCG may be of some help in counseling women with such results and raise awareness among health-care professionals for increased surveillance in such cases.

Spencer K ，Cowans NJ ，Avgidou K ，Nicolaides KH ... -  《ULTRASOUND IN OBSTETRICS & GYNECOLOGY》