Dr. Nguyen Hoang Long, from the Fetal Medicine Unit at Tam Anh General Clinic, District 7, explains that twin or multiple pregnancies can increase complications for both the mother and babies. These pregnancies require adherence to a regular prenatal check-up schedule for close monitoring, appropriate interventions, and preventative measures.

Premature birth is a significant risk in twin pregnancies. The expansion of the uterus, the number and weight of the fetuses, and the larger placenta size increase uterine activity, leading to a higher rate of premature labor compared to singleton pregnancies. The pressure of the fetuses, amniotic fluid, and placenta on the cervix also elevates this risk. Other factors like preeclampsia, gestational diabetes, polyhydramnios, and complications associated with monochorionic twins further contribute to premature birth.

Premature babies are often underweight and may require respiratory support, nutritional assistance, thermoregulation, and infection control due to underdeveloped organs not fully functional outside the womb. Dr. Long recommends cervical length measurements via ultrasound for mothers expecting twins or multiples between 18 and 24 weeks to screen for premature birth risk. This allows for preventative measures such as cervical cerclage or medication.

Preeclampsia is another concern. Dr. Long cites studies showing that the rate of preeclampsia in twin pregnancies is around 10%, three times higher than in singleton pregnancies. While preeclampsia typically occurs after 20 weeks, it can appear earlier and be more severe in multiple pregnancies. This puts the babies at risk of slow growth, fetal distress, premature birth, and sudden fetal demise. The mother faces potential complications like eclampsia, HELLP syndrome (elevated liver enzymes, low platelets, hemolysis), multiple organ failure, and even death.

Preeclampsia screening is performed regularly throughout pregnancy, most importantly between 11 and 13 weeks. High-risk mothers are given preventative aspirin and closely monitored.

Dr. Long consults with an expectant mother at Tam Anh General Clinic, District 7. Photo illustration: Thanh Luan

Dr. Long consults with an expectant mother at Tam Anh General Clinic, District 7. Photo illustration: Thanh Luan

Twin-to-twin transfusion syndrome (TTTS) occurs in monochorionic-diamniotic twins. Due to an imbalance in the connecting blood vessels between the twins, blood is transferred from the donor twin to the recipient twin. The donor twin experiences reduced blood volume, risking malnutrition, multiple organ failure, and oligohydramnios (low amniotic fluid). The recipient twin becomes overloaded, exhibiting polyhydramnios (excess amniotic fluid), edema, and heart failure. These signs can appear from 16 weeks, affecting about 10% of monochorionic twins. TTTS significantly increases the risk of fetal demise. Without appropriate treatment, about 80% of cases result in the loss of at least one twin. When one twin's heart stops, it can cause brain damage or fetal demise in the surviving twin, according to Dr. Long.

Early diagnosis through regular ultrasounds and advanced treatments like laser surgery to sever the connecting blood vessels can save lives and reduce long-term complications.

Twin reversed arterial perfusion (TRAP) sequence, also known as acardiac twinning, typically occurs in monochorionic twins. One twin lacks a functional heart or has an underdeveloped heart and receives blood pumped by the other twin through shared blood vessels. The acardiac twin is underdeveloped, often missing body parts. The pump twin is at risk of heart failure, brain damage, and premature birth.

First-trimester ultrasounds can detect TRAP sequence. Treatment focuses on monitoring the pump twin's heart function to intervene at the right time and stop blood flow to the acardiac twin.

Selective intrauterine growth restriction (sIUGR) occurs when one twin grows slower than the other due to unequal placental sharing of nutrients. The growth-restricted twin faces mortality, while the other twin risks anemia or complications from a stillbirth, leading to premature delivery.

Close monitoring with regular ultrasounds, fetal heart rate monitoring, and assessment of fetal blood circulation are essential. This informs the doctor's treatment plan, which might include laser surgery to sever connecting blood vessels or umbilical cord occlusion.

Polycythemia-anemia sequence results from slow blood transfusion between twins through small connecting vessels. One twin develops anemia, while the other develops polycythemia (an excess of red blood cells). Both twins risk heart failure, fetal hydrops (fluid buildup), and fetal demise. This condition can be detected as early as 16 weeks and managed with monitoring and interventions like laser surgery or blood transfusions.

Ngoc Chau