Types of twin pregnancy

Dichorionic diamniotic (DCDA). Each baby has their own placenta and sac. Most common type, lowest risk. Monochorionic diamniotic (MCDA). Babies share a placenta but have separate sacs. Requires monitoring for twin-to-twin transfusion syndrome. Monochorionic monoamniotic (MCMA). Babies share both a placenta and a sac. Rarest and highest-risk type.

Your type will be determined at your dating scan, ideally before 14 weeks.

How antenatal care changes

DCDA twins have scans every 4 weeks from 24 weeks. MCDA twins have scans every 2 weeks from 16 weeks. MCMA twins are monitored from 16 weeks with very frequent scans and may be admitted to hospital from around 24 to 26 weeks.

Twin pregnancies are consultant-led rather than midwife-led.

Common differences in how you feel

Morning sickness may be more severe. You may show earlier and feel heavier sooner. Fatigue is often more pronounced. Breathlessness, heartburn, back pain, and pelvic girdle pain tend to be more significant. You need roughly 300 to 500 extra calories per day on top of normal intake.

Complications to be aware of

Premature birth is the most significant risk: around half of twin pregnancies deliver before 37 weeks. Pre-eclampsia, gestational diabetes, and anaemia are all more common. For MCDA twins, twin-to-twin transfusion syndrome (TTTS) is monitored through fortnightly scans and can be treated with laser surgery.

Delivery

DCDA twins are usually planned for delivery between 37 and 38 weeks. MCDA twins between 36 and 37 weeks. MCMA twins around 32 to 34 weeks by planned caesarean.

Vaginal birth is possible and safe in many cases. An epidural is usually recommended because it allows for quick intervention if the second baby needs help.

Practical support

Twins Trust (formerly TAMBA) offers a helpline, antenatal classes for multiples, and practical resources at twinstrust.org.

Twins and Multiples: What Makes Your Pregnancy Different