Outcome of Multifetal Pregnancy Reduction in Women with a Dichorionic Triamniotic Triplet Pregnancy to a Singleton Pregnancy: A Retrospective Nationwide Cohort Study.

OBJECTIVE: To study the pregnancy outcomes of women with a dichorionic triamniotic triplet pregnancy that was reduced to a singleton pregnancy and to review the literature. METHODS: We performed a nationwide retrospective cohort study. We compared time to delivery and perinatal mortality in dichorionic triplet pregnancies reduced to singletons with ongoing dichorionic triplet pregnancies and primary singleton pregnancies. Additionally, we reviewed the literature on the subject. RESULTS: We studied 46 women with a reduced dichorionic triplet pregnancy and 42 women with an ongoing dichorionic triplet pregnancy. Median gestational age at delivery was 38.7 vs. 32.8 weeks, respectively (p < 0.001). Delivery <24 weeks occurred in 9 (19.6%) women with a reduced triplet pregnancy and 4 (9.5%) with an ongoing triplet pregnancy (p = 0.19). Perinatal survival rates between the reduced group and the ongoing triplet group were not significantly different. CONCLUSION: Multifetal pregnancy reduction in women with a dichorionic triplet pregnancy to a singleton pregnancy prolongs median gestational age at birth. No statistically significant association was found with miscarriage and perinatal survival rates.

Pregnancy outcome after fetal reduction in women with a dichorionic twin pregnancy.

STUDY QUESTION: What are the pregnancy outcomes for women with a twin pregnancy that is reduced to a singleton pregnancy? SUMMARY ANSWER: Fetal reduction of a twin pregnancy significantly improves gestational age at birth and neonatal birthweight, however at an increased risk of pregnancy loss and preterm delivery. WHAT IS KNOWN ALREADY: Women with a multiple pregnancy are at increased risk for preterm delivery. Fetal reduction can be considered in these women. STUDY DESIGN, SIZE, AND DURATION: Retrospective cohort study of 118 women with a twin pregnancy reduced to a singleton pregnancy between 2000 and 2010. PARTICIPANTS/MATERIALS, SETTING, AND METHODS: We compared the outcome of pregnancy in consecutive women with a dichorionic twin pregnancy that was reduced to a singleton pregnancy to that of women with a dichorionic twin pregnancy that was managed expectantly and women with a primary singleton pregnancy. Reductions were performed between 10-23(6/7) weeks' gestation by intracardiac or intrathoracic injection of potassium chloride, mostly for congenital anomalies. We compared median gestational age, pregnancy loss <24 weeks, preterm delivery <32 weeks, neonatal birthweight and perinatal deaths. MAIN RESULTS AND THE ROLE OF CHANCE: We studied 118 women with a twin pregnancy that was reduced to a singleton, 818 women with an ongoing dichorionic twin pregnancy and 611 women with a primary singleton pregnancy. Loss of the entire pregnancy <24 weeks and preterm delivery occurred significantly more in the reduction group compared with the ongoing twin group (11.9 versus 3.1% <24 weeks, P< 0.001 and 18.6 versus 11.5% <32 weeks, respectively, P < 0.001). In the reduction group, the percentage of women without any surviving child was significantly higher compared with the ongoing twin and primary singleton group (14.4, 3.4 and 0.7%, respectively, P < 0.001). Median gestational age was 38.9 weeks (interquartile range (IQR) 34.7-40.3) for reduced pregnancies, 37.1 weeks (IQR 35.3-38.1) for ongoing twin pregnancies and 40.1 (IQR 39.1-40.9) for primary singletons (P < 0.001 for all comparisons). LIMITATIONS, REASONS FOR CAUTION: The main limitations of the study were its retrospective character, and the fact that indications for reduction were heterogeneous. WIDER IMPLICATIONS OF THE FINDINGS: In women with a dichorionic twin pregnancy fetal reduction increases median gestational age only at considerable risk of complete early pregnancy loss. STUDY FUNDING/COMPETING INTERESTS: The study was not funded. None of the authors has conflicts of interest.

Age independent first trimester screening for Down syndrome: improvement in test performance.

OBJECTIVE: The aim of this study was to compare screening performance for Down syndrome of the absolute risk (AR) method to the first trimester combined test (FCT) at different maternal ages. METHODS: There was a retrospective analysis of 32,448 FCT. AR was defined as final risk divided by maternal age risk. RESULTS: The likelihood of receiving a true prediction was comparable between both methods in all age groups. With the AR method, two extra Down syndrome cases were detected in women <30 years, three cases were missed in women ≥36 years, and the likelihood of receiving a false prediction decreased overall (OR 0.82, CI 0.77-0.87; P < 0.0001), in women aged 36-40 years (0.45, CI 0.41-0.51; P < 0.0001), in women aged 41-45 years (0.18, CI 0.13-0.26; P < 0.0001) and increased in women aged ≤25 years (2.12, CI 1.52-2.96; P < 0.004). CONCLUSIONS: The AR method results in a significant decreased likelihood of receiving a false prediction with a comparable likelihood of receiving a true prediction. Thus, fewer invasive diagnostic tests will be performed. It will take away the misunderstanding about differences in screening performance for women of different ages. This might lead to a higher uptake of first trimester screening resulting in a more efficient screening policy.

First-trimester serum marker distribution in singleton pregnancies conceived with assisted reproduction.

OBJECTIVE: To evaluate marker distribution of free beta-human chorionic gonadotrophin (fbeta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in singleton pregnancies conceived by assisted reproduction techniques (ART). METHODS: In vitro fertilization (IVF) (n = 203) and intracytoplasmic sperm injection (ICSI) (n = 192) cases from a database of 14 645 first-trimester combined tests (overall study group) were selected and matched to 1164 controls for gestational age at sample date and maternal age. RESULTS: In the IVF group and ICSI group, lnPAPP-A was lower (IVF 6.74 vs 7.08; P = 0.0001; ICSI 6.59 vs 7.07; P = 0.0001) compared with the matched controls. Lnfbeta-hCG was lower in the IVF group (3.75 vs 3.90; P = 0.005) but not significantly different in the ICSI group (3.87 vs 3.93; P = 0.27). The computed correction factors for PAPP-A and fbeta-hCG were 1.42 and 1.17 for the IVF group and 1.56 and 1.05 for the ICSI group.The false-positive rate (FPR) in the IVF and ICSI group compared with the matched controls was higher (IVF 10.3% vs 8.6% and ICSI 10.9% vs 7.5%). In the overall age-biased [maternal age significantly lower compared with all ART and control groups] study group the FPR was 6.8%. CONCLUSION: The increase in FPR in the ART groups can be explained by decreased PAPP-A values. Therefore, an adjustment in risk analysis for Down syndrome is suggested.

Quality of nuchal translucency measurements in The Netherlands: a quantitative analysis.

OBJECTIVE: The Dutch Centre for Population Research has specified quality demands for nuchal translucency (NT) measurement in The Netherlands. We performed an analysis of the quality of NT measurement in 2005-2006 and its influence on screening performance. METHODS: This was a retrospective study of records of NT measurements (n = 27,738) obtained between January 2005 and December 2006 retrieved from the Dutch National Institute for Public Health and the Environment (RIVM). The performance of each individual operator was analyzed with regard to the quality standards, which involved calculation of operator-specific median NT-multiples of the median (MoM) values. For the entire population of operators, a curve was determined describing the relationship between crown-rump length and NT. Detection rates (DR) and false-positive rates (FPR) for Down syndrome were modeled with this new curve and compared to those originally obtained using previously published reference data. RESULTS: Only 22% of all operators met the quality requirement of performing more than 150 NT measurements per year. However, no relationship was found between the number of measurements per operator and their median NT-MoM. The mean of all operator-specific median NT-MoM values was 0.94 (target value 1.0). Overall, operators with The Fetal Medicine Foundation certificate measured a significantly higher median NT-MoM (mean of operator-specific medians, 0.98) as compared to the non-certified operators (0.92). During the study period, the monthly median NT-MoM of all operators rose steadily, from 0.86 in January 2005 to 0.96 in December 2006. Recalculation of the risk for Down syndrome after adjusting the reference NT medians using our own data led to a modeled 4% increase in DR at a 5% FPR. CONCLUSION: Improved monitoring of NT measurement put into effect during the study period seems to have led to an improvement in the accuracy of measurements. Strict quality demands, continued monitoring and scrupulous evaluation of individual operators is likely to lead to an even better performance.

Normal fetal lung volume measured with three-dimensional ultrasound.

OBJECTIVES: To construct reference intervals for fetal lung volumes measured longitudinally using three-dimensional (3D) ultrasound, and to evaluate the effect of gender on lung size. METHODS: This was a prospective, longitudinal study in the obstetric outpatient department of the VU University Medical Center, Amsterdam. Seventy-eight women with uncomplicated pregnancies were scanned three to four times at gestational ages of 18-34 weeks. 3D models of the lung were constructed using the ultrasound machine's software. After the infants were delivered the entire group was reanalyzed with regard to fetal gender. Centiles for the lung volumes of the entire group and for each gender separately were estimated using multilevel modeling. RESULTS: Charts and tables of right and left fetal lung volumes, using gestational age and estimated fetal weight as the independent variables, are presented. There was a significant difference in lung volume between male and female fetuses at each gestational age. Charts and tables of right and left fetal lung volumes for each gender at gestational ages of 18-34 weeks are also presented. CONCLUSIONS: We present valid references for volumetric measurements of the right and left fetal lungs in male and female fetuses. The feasibility and reliability of fetal lung volume measurements using 3D ultrasound is good.