In 70% of identical twin pregnancies, the twins share a single placenta in the womb that provides them with nutrients. This shared placenta can be unequaly shared. This means that one of the twins... Show moreIn 70% of identical twin pregnancies, the twins share a single placenta in the womb that provides them with nutrients. This shared placenta can be unequaly shared. This means that one of the twins has a much smaller share of the placenta compared to the other twin, resulting in a large growth discrepancy during pregnancy, also known as 'selective fetal growth restriction'. At birth, a large difference in birth weight ensues. Sometimes one twin can be almost twice the size of the other twin.These twins are considered a vulnerable patient group in which perinatal complications are prevalent. Nevertheless, a large gap in knowledge persists, impeding proper parent counseling and risk assessment by health care providers. Simultaneously, these twins can also be considered a unique natural 'experiment' to uncover the early origins of health and disease following an adverse environment in the womb. The growth-restricted twin can be compared to a genetically identical, normally-grown twin who has been in the same womb of the same mother at the same time.In this thesis, Sophie Groene has investigated the placental mechanisms and the short- and long-term outcomes of this special group of twins. Show less
This thesis deals with various aspects of twin anemia polycythemia sequence (TAPS). TAPS is a condition that can develop due to unbalanced feto-fetal blood transfusion through minuscule vascular... Show moreThis thesis deals with various aspects of twin anemia polycythemia sequence (TAPS). TAPS is a condition that can develop due to unbalanced feto-fetal blood transfusion through minuscule vascular placental anastomoses in monochorionic twin pregnancies, causing the donor twin to become anemic and the recipient twin to become polycythemic. In this thesis we show that a difference in middle cerebral artery peak systolic velocity (MCA-PSV) > 0.5 Multiples of the Median (MoM) has a high diagnostic accuracy for the the antenatal diagnosis of TAPS. For postnatal diagnosis of the condition, inspection of the color of the maternal side of the placenta can be of great value. Furthermore, we present the results of a large international registry, and report on outcomes after different treatment options for TAPS. As the best treatment for TAPS is unclear, we propose the protocol of The TAPS Trial (a multicenter open-label international RCT) to investigate the potential beneficial effect of fetoscopic laser surgery for the outcome in TAPS twins . In the last chapters of this thesis we discuss short- and long-term outcome and show that TAPS donors show significantly higher rates of perinatal mortality and long-term neurodevelopmental impairment than their recipient co-twins. Show less
Monochorionic twins are at increased risk of complications compared to dichorionic twins due to differences in placentas. Nearly all monochorionic twins have placental anastomoses connecting... Show moreMonochorionic twins are at increased risk of complications compared to dichorionic twins due to differences in placentas. Nearly all monochorionic twins have placental anastomoses connecting the blood circulation of both twins, whereas dichorionic twins have always two separate placentas without vascular connections. Vascular anastomoses lead to inter-twin blood transfusion, which is ‘balanced’ in uncomplicated monochorionic twins. In twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS) inter-twin blood transfusion is unbalanced, resulting in high mortality rates if left untreated. However, improved antenatal management has led to an increase in perinatal survival. Attention is now shifting towards postnatal complications in survivors. In this thesis hematological and biochemical complications in twins affected by TTTS or TAPS are evaluated, including albumin levels and short-term postnatal renal function and hemoglobin levels in uncomplicated monochorionic twins and dichorionic twins. Show less
