From the Guidelines
The most appropriate next step in managing a 36-year-old primigravid woman with a monochorionic-diamniotic (mono-di) twin pregnancy at 27 weeks gestation, with normal fetal heart rates and no other complications, is to continue with routine prenatal care and ultrasound surveillance every 2 weeks, as recommended by the Society for Maternal-Fetal Medicine 1.
Given the patient's current gestational age and the absence of any complications, the focus should be on monitoring for potential issues such as twin-twin transfusion syndrome (TTTS) and twin anemia-polycythemia sequence (TAPS). The Society for Maternal-Fetal Medicine recommends that ultrasound surveillance for TTTS begin at 16 weeks of gestation for all MCDA twin pregnancies and continue at least every 2 weeks until delivery 1.
Key components of this surveillance should include:
- Assessment of amniotic fluid volumes on both sides of the intertwin membrane
- Evaluation for the presence or absence of urine-filled fetal bladders
- Doppler study of the umbilical arteries, as ideally recommended 1
It is also important to note that the patient should be educated about warning signs that would necessitate immediate medical attention, such as decreased fetal movement, vaginal bleeding, or preterm labor symptoms.
Delivery timing for uncomplicated monochorionic diamniotic twins is typically recommended between 34-36 weeks of gestation, as suggested by the Society for Maternal-Fetal Medicine 1. However, the decision on the timing of delivery should be individualized based on the patient's specific situation and the presence of any complications.
Overall, the management of this patient should prioritize close monitoring for potential complications and preparation for delivery at the appropriate gestational age, with the goal of minimizing morbidity, mortality, and optimizing quality of life for both the mother and the fetuses.
From the Research
Management of Monochorionic-Diamniotic Twin Pregnancy
- The patient is at 27 weeks gestation with a monochorionic-diamniotic (mono-di) twin pregnancy, which is at risk for twin-to-twin transfusion syndrome (TTTS) due to the shared placenta and intertwin anastomoses 2, 3.
- TTTS can lead to severe hemodynamic imbalance, resulting in polyhydramnios in the recipient twin and oligohdramnios in the donor twin, and can increase the risk of fetal death, end-organ damage, and preterm birth 2, 3, 4.
- Surveillance with ultrasound is essential for detection and treatment of TTTS, and the diagnosis is typically made by ultrasound findings of polyhydramnios and oligohdramnios, as well as assessment of bladder filling and Doppler patterns 2, 3, 5.
Next Steps in Management
- Given that the patient has a mono-di twin pregnancy at 27 weeks gestation with normal fetal heart rates and no other complications, the next step would be to continue close surveillance with ultrasound to monitor for signs of TTTS 2, 3.
- The patient should be monitored for polyhydramnios and oligohdramnios, as well as other signs of TTTS, such as abnormal bladder filling and Doppler patterns 5.
- If TTTS is diagnosed, fetoscopic laser photocoagulation of placental anastomoses is an effective treatment that can improve survival rates and reduce the risk of fetal death and preterm birth 2, 3, 6.