Screening for Down syndrome in dichorionic twin pregnancies conceived by in vitro fertilization (IVF): a clinical pilot study to confirm the laboratory methods

Abstract

Purpose The corrections necessary to estimate the risk for Down syndrome in twin pregnancies have been pointed out. We performed a nested controlled study to evaluate the validity of these corrections in dichorionic twins conceived by IVF. Methods Detailed clinical data was collected from the medical records. Twins were matched with a contemporaneous cohort of spontaneously conceived singleton pregnancies that serve as reference in a 1 to 4 ratio. All patients had their entire obstetrical care at our Hospital. The Student t-test was used for group comparisons and a p-value <0.05 was considered significant. Results Nineteen sets of normal twins concordant in size and with appropriate weight for gestational age were matched with 80 normal and mature newborns. Significant differences between groups were found for maternal age, gestational age at delivery and newborn weight (all p <0.01). No statistical differences were noted for the levels of the biochemical markers expressed as multiples of the median. However, a 15 % closer approximation to the laboratory median for PAPP-A and a 10 % closer approximation to the laboratory median for free β-hCG was evident in twins when compared to the reference group. Conclusions These findings support the methods used to estimate the risk for Down syndrome in dichorionic twin pregnancies conceived after IVF. A future study with a larger sample size could confirm if the laboratory corrections done on the combined screening test improve the predictability of Down syndrome in dichorionic twin pregnancy conceived by IVF when compared to singleton pregnancies.

Патология Плода И Плаценты После Применения ВРТ: Данные Ретроспективного Исследования

“…Группа сравнения 3,1% (5) 0 0,6% (1) костно-мышечной системы -2,5% против 1,3% (ОШ = 1,8; 95% ДИ: 1,33-6,25; p=0,24). Пороки желудочно-кишечного тракта отмечались только в группе ВРТ (рисунок 2), что согласуется с данными литературы [17][18][19][20].…”

“…4. В нашем исследовании были выявлены ВПР сердечно-сосудистой, мочевыделительной, костной систем и желудочно-кишечного тракта, что согласуется с данными литературы в которых установлен высокий риск хромосомных дефектов, пороков развития урогенитальных органов и системы кровообращения [17][18][19]. Так, в исследовании 2015 г. с участием 11 890 женщин после применения ВРТ и 1 118 162 в группе сравнения относительный шанс развития ВПР составил 1,43 (95% ДИ: 1,19-1,72) наступившей с применением ВРТ [20].…”

Prenatal screening for chromosomal abnormalities in IVF patients that opted for preimplantation genetic screening/diagnosis (PGS/D): a need for revised algorithms in the era of personalized medicine

“…Patients not interested in prenatal diagnosis should have prenatal screening for chromosomal abnormalities and a detailed sonographic evaluation for congenital anomalies. One of the problems for obstetricians managing IVF-PGS/D patients is that prenatal screening tests for chromosomal abnormalities are based on Bayesian analysis in which the maternal age-related risk is the a priori risk that will be modified by the results of a combination of maternal serum and sonographic biomarkers evaluated at defined gestational age windows [12]. These screening algorithms do not take into consideration that the embryo was selected using PGD/S causing confusion, emotional distress in the patient, and final estimations of risk for chromosomal abnormalities that are not accurate.…”