ABSTRACT
OBJECTIVE: To evaluate the distribution of first- and second-trimester maternal serum markers in twin pregnancy with and without pre-eclampsia. METHODS: One-hundred and forty-four twin and 109 unaffected singleton pregnancies were recruited from the same institution. First- and second-trimester maternal blood samples were stored and measured retrospectively for serum placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A), free ß-human chorionic gonadotropin (ß-hCG) and α-fetoprotein (AFP). All had measurement of first-trimester serum markers, and 167 (66%) had second-trimester tests. Values were expressed in multiples of the gestation-specific median (MoMs) in singletons, adjusted for maternal weight, as appropriate. RESULTS: Pre-eclampsia was diagnosed in 12 (9.0%) twin pregnancies of 133 continuing beyond 22 weeks. In unaffected twin pregnancies, all serum markers were statistically significantly increased (P < 0.0001), consistent with a doubling of concentration. Among twin pregnancies, those with pre-eclampsia had a significantly reduced median PlGF compared with surviving unaffected twin pregnancies (0.96 MoM vs 1.46 MoM; P < 0.0002, two-tailed), whilst median PAPP-A, which is known to be reduced in affected singleton pregnancies, was increased (3.91 MoM vs 2.43 MoM; P < 0.0005, two-tailed). The levels of free ß-hCG (P < 0.02) and AFP (P < 0.05) were also significantly raised, but to a lesser extent than was the level of PAPP-A. Using a logistic regression algorithm based on first- and second-trimester PlGF and PAPP-A, together with previously published uterine artery Doppler and mean arterial pressure measurements in the same series, the predicted pre-eclampsia detection rate was 65% for a 10% false-positive rate. CONCLUSIONS: In twin pregnancy, the predicted detection rate of pre-eclampsia using first- and second-trimester maternal serum and biophysical markers is good. In contrast to singleton pregnancy, PAPP-A levels are raised in the first trimester of twin pregnancies destined to develop pre-eclampsia and therefore a different prediction algorithm is needed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Subject(s)
Biomarkers/blood , Pre-Eclampsia/diagnosis , Pregnancy, Twin/blood , Adult , Chorionic Gonadotropin, beta Subunit, Human/blood , Female , Humans , Placenta Growth Factor/blood , Pre-Eclampsia/metabolism , Pregnancy , Pregnancy Trimester, First/blood , Pregnancy Trimester, Second/blood , Pregnancy-Associated Plasma Protein-A/metabolism , Sensitivity and Specificity , alpha-Fetoproteins/metabolismABSTRACT
OBJECTIVES: To construct tables for 'bedside' estimation of Down syndrome risk based on maternal age and ultrasound prenasal thickness (PT) measurements. METHODS: Likelihood ratios were calculated using a log Gaussian model of the PT distribution in multiples of the gestational age-specific median (MoM). The model parameters were derived from 80 Down syndrome and 850 unaffected pregnancies scanned at 14-27 weeks; these data had been published previously, in three series, except for 18 Down syndrome and 119 affected pregnancies. The means were estimated as the median, and the SDs as the 10(th)-90(th) range divided by 2.563. RESULTS: A log Gaussian model fitted well the distribution of PT values in Down syndrome and unaffected pregnancies with medians of 1.31 MoM and 1.01 MoM, and log(10) SDs of 0.075 and 0.082, respectively. CONCLUSIONS: The tables provide a simple 'bedside' estimation of Down syndrome risk without the need for computerized software or complicated calculations. More prospective data on PT in combination with other first- and second-trimester screening markers are needed.
Subject(s)
Down Syndrome/diagnostic imaging , Models, Statistical , Nasal Bone/diagnostic imaging , Adolescent , Adult , Biometry , Female , Gestational Age , Humans , Maternal Age , Nasal Bone/embryology , Pregnancy , Pregnancy Trimester, Second , Reference Values , Risk Assessment , Ultrasonography, Prenatal , Young AdultABSTRACT
Coasting is a method to decrease the incidence of ovarian hyperstimulation syndrome (OHSS), which involves withdrawing exogenous gonadotrophins until the serum estradiol (E(2)) level decreases. The application of this strategy, as it appears in the literature, has been variable, with heterogeneous criteria for initiating and ending the coasting process and as a result, reports of efficacy are inconsistent. In attempt to establish a recommended protocol for coasting we reviewed and analysed 10 relevant studies, found by a Medline search. Based on the data collected, coasting should be initiated when the serum E(2) concentration exceeds 3000 pg/ml, but not unless the leading follicles reach a diameter of 15-18 mm. Its duration should be limited to <4 days, thus, preventing the decrease in implantation and pregnancy rates that occur after longer periods of coasting. Administration of hCG should be withheld until serum E(2) falls below 3000 pg/ml. Based on the published data, these suggested guidelines result in an acceptably low incidence of severe OHSS (<2%) and provide satisfactory fertilization and pregnancy rates (55-71% and 36.5-63% respectively). A multicentre randomized prospective study would help to confirm the effectiveness of this approach.
