Twin Pregnancy Risks: What Expecting Mothers Need to Know

First trimester complications

The first 12 weeks are a critical time for any pregnancy, but with twins, the stakes feel even higher. Common first-trimester complications include:

• Vanishing twin syndrome: In about 20–30% of twin pregnancies, one baby stops developing and is absorbed by the mother’s body. This usually happens in the first trimester and often goes unnoticed, but it can cause mild cramping or spotting. Most moms go on to deliver a healthy singleton.
• Hyperemesis gravidarum: Severe nausea and vomiting affect about 1–2% of singleton pregnancies, but up to 8% of twin pregnancies. If you can’t keep fluids down, your doctor may prescribe anti-nausea medication or recommend IV fluids.
• Miscarriage: The risk of miscarriage is slightly higher in twin pregnancies, especially in the first trimester. Signs include heavy bleeding, severe cramping, or passing tissue. Call your doctor immediately if you experience these symptoms.

Second trimester complications

The second trimester is often called the “honeymoon phase” of pregnancy, but with twins, it’s also when some of the most serious complications can emerge. These include:

• Twin-to-twin transfusion syndrome (TTTS): This condition usually develops between 16 and 26 weeks. One baby (the “donor”) sends too much blood to the other (the “recipient”), causing one to grow too slowly and the other to develop heart problems. TTTS is a medical emergency and requires immediate treatment, often with laser surgery to seal off the abnormal blood vessels.
• Selective intrauterine growth restriction (sIUGR): One twin grows significantly slower than the other, often due to an uneven distribution of blood flow. This affects about 10–15% of identical twins who share a placenta.
• Preterm labor: Contractions, pelvic pressure, or a change in vaginal discharge can signal early labor. With twins, preterm labor is more common, so your doctor will monitor you closely for signs.
• Gestational diabetes: Your glucose tolerance test will likely happen earlier in a twin pregnancy — often around 24–28 weeks, instead of 28 weeks for singletons. If you develop gestational diabetes, you’ll work with a dietitian to manage your blood sugar through diet and, if needed, medication.
• Pre-eclampsia: High blood pressure and protein in your urine can develop as early as 20 weeks in a twin pregnancy. Symptoms include severe headaches, vision changes, swelling in your hands and face, and sudden weight gain. Pre-eclampsia is more common and often more severe with twins, so your doctor will check your blood pressure at every visit.

Third trimester complications

The third trimester is when the risks of preterm birth and other complications peak. Common concerns include:

• Preterm premature rupture of membranes (PPROM): Your water breaks before 37 weeks. With twins, this happens in about 7–10% of pregnancies. If your water breaks early, your doctor will likely recommend hospitalization to monitor you and your babies.
• Placental abruption: The placenta detaches from the uterine wall before delivery, cutting off oxygen and nutrients to the babies. This is a medical emergency and requires an immediate C-section. Signs include sudden, severe abdominal pain, bleeding, and contractions.
• Cholestasis of pregnancy: A liver condition that causes intense itching, especially on the hands and feet. It’s more common in twin pregnancies and increases the risk of preterm birth and stillbirth. If you develop cholestasis, your doctor will monitor your bile acid levels and may induce labor early.
• Fetal distress: One or both babies may show signs of distress, such as an abnormal heart rate, during labor. This is more common with twins and may require an emergency C-section.

One mom, Priya, shared her experience with preterm labor at 32 weeks: “I was at work when I started feeling cramps every 10 minutes. I thought it was just Braxton Hicks, but my doctor told me to come in. They gave me steroids to help the babies’ lungs develop and put me on bed rest for the next two weeks. It was scary, but those extra two weeks made a huge difference — my girls were born at 34 weeks and only needed a short NICU stay.”

How can I reduce the risks in a twin pregnancy?

While you can’t eliminate every risk, there are steps you can take to give yourself and your babies the best possible outcome. Think of it as a team effort: you do your part at home, and your care team handles the medical side. Here’s what you can control:

1. Choose the right care team

Not all obstetricians have extensive experience with twin pregnancies. Look for a provider who:

• Has delivered many twins (ask how many per year).
• Works with a maternal-fetal medicine (MFM) specialist, especially if you’re carrying identical twins or have other risk factors.
• Has privileges at a hospital with a Level III or IV NICU (neonatal intensive care unit). This is crucial if your babies arrive early.

Many moms of twins switch to a perinatologist (a high-risk pregnancy specialist) around 12–16 weeks. This isn’t because something is wrong — it’s because twin pregnancies benefit from extra monitoring and expertise. One reader, Maria, said: “I was nervous about seeing a ‘high-risk’ doctor, but my perinatologist put me at ease. She explained everything, answered all my questions, and made me feel like I was in the best possible hands.”

2. Eat for three (but not too much)

You’ll need more calories with twins — about 600 extra per day in the second and third trimesters. But quality matters just as much as quantity. Focus on:

• Protein: Aim for 100 grams per day to support your babies’ growth. Good sources include lean meats, eggs, dairy, beans, and tofu.
• Iron: Twin moms are at higher risk for anemia. Eat iron-rich foods like spinach, red meat, and lentils, and take a prenatal vitamin with iron. Your doctor may also recommend an additional iron supplement.
• Calcium: You’ll need about 1,500 mg per day to support your babies’ bone development. Dairy, fortified plant milks, and leafy greens are great sources.
• Healthy fats: Avocados, nuts, seeds, and fatty fish (like salmon) help your babies’ brain development.
• Fiber: Constipation is common in twin pregnancies, so load up on fruits, vegetables, and whole grains.

Avoid empty calories from sugary snacks and processed foods. They won’t help your babies grow and can contribute to excessive weight gain, which increases the risk of gestational diabetes and pre-eclampsia.

3. Stay hydrated

Dehydration can trigger contractions and increase the risk of preterm labor. Aim for at least 10–12 cups of water per day, and more if you’re active or it’s hot outside. If you’re struggling to drink enough, try:

• Infusing your water with fruit (lemon, cucumber, or berries).
• Sipping herbal teas (check with your doctor first to make sure they’re safe).
• Eating hydrating foods like watermelon, cucumbers, and soups.

Signs of dehydration include dark yellow urine, dizziness, and a dry mouth. If you notice these, drink a large glass of water and call your doctor if symptoms don’t improve.

4. Exercise — but listen to your body

Staying active can help reduce the risk of gestational diabetes, pre-eclampsia, and preterm birth. But with twins, you’ll need to modify your routine. Safe exercises include:

• Walking (aim for 30 minutes most days).
• Prenatal yoga or Pilates (avoid poses that involve lying on your back after the first trimester).
• Swimming or water aerobics (the water supports your joints and reduces swelling).
• Stationary biking (low impact and easy on your joints).

Avoid contact sports, activities with a risk of falling (like skiing or horseback riding), and anything that involves lying flat on your back after 16 weeks. Stop exercising if you experience:

• Contractions or pelvic pressure.
• Vaginal bleeding or fluid leakage.
• Dizziness or shortness of breath.
• Chest pain or a headache.

Always check with your doctor before starting a new exercise routine. Some twin moms are placed on partial or full bed rest, especially in the third trimester. If that happens, follow your doctor’s instructions closely.

5. Manage stress

Stress won’t directly cause complications, but it can take a toll on your mental and physical health. High stress levels are linked to higher rates of preterm birth and low birth weight. To keep stress in check:

• Prioritize sleep: Aim for 8–9 hours per night. Use pillows to support your belly and back, and try to sleep on your left side to improve blood flow to your babies.
• Ask for help: Whether it’s meal prep, cleaning, or just someone to listen, don’t hesitate to lean on your partner, family, and friends.
• Practice relaxation techniques: Deep breathing, meditation, and prenatal massage can all help lower stress levels. Apps like Expectful or Headspace offer guided meditations for pregnancy.
• Talk to a therapist: If you’re feeling overwhelmed, anxious, or depressed, a therapist can help. Many specialize in perinatal mental health.

One mom, Lisa, shared: “I was so anxious about preterm labor that I barely slept. My therapist helped me focus on what I could control — eating well, staying hydrated, and going to all my appointments. It made a huge difference in how I felt.”

6. Attend all your prenatal appointments

With twins, you’ll see your doctor more often — usually every 2–3 weeks in the first and second trimesters, and weekly in the third trimester. These appointments are your best defense against complications. Your doctor will:

• Monitor your babies’ growth with ultrasounds (often every 4 weeks starting at 16 weeks).
• Check for signs of preterm labor, pre-eclampsia, and gestational diabetes.
• Measure your cervical length (a short cervix increases the risk of preterm birth).
• Discuss your birth plan and any concerns you have.

Don’t skip appointments, even if you’re feeling fine. Many complications, like TTTS or pre-eclampsia, don’t have obvious symptoms until they’re advanced. Early detection is key.

7. Know the warning signs

Some symptoms are normal in a twin pregnancy (like fatigue or back pain), but others require immediate medical attention. Call your doctor right away if you experience:

• Contractions every 10 minutes or more (even if they’re painless).
• Vaginal bleeding or fluid leakage.
• Severe abdominal pain or cramping.
• Sudden swelling in your hands, face, or feet.
• Severe headaches, vision changes, or dizziness.
• A decrease in your babies’ movement (after 28 weeks, you should feel at least 10 movements per hour).

It’s always better to be safe than sorry. If something doesn’t feel right, trust your instincts and call your doctor.

What are the risks of a twin pregnancy at 20 weeks?

Reaching 20 weeks with twins is a big milestone — you’re halfway there! But this is also when some of the most serious complications can emerge, especially if you’re carrying identical twins. Here’s what to watch for at this stage:

Twin-to-twin transfusion syndrome (TTTS)

TTTS is one of the most serious risks for identical twins who share a placenta. It usually develops between 16 and 26 weeks, so 20 weeks is right in the danger zone. In TTTS, abnormal blood vessels in the shared placenta cause one baby (the “donor”) to send too much blood to the other (the “recipient”). This can lead to:

• For the donor baby: Slow growth, low amniotic fluid, and anemia.
• For the recipient baby: Too much amniotic fluid, heart strain, and an increased risk of heart failure.

TTTS is classified into five stages, from mild (Stage I) to severe (Stage V). Treatment depends on the stage and how far along you are. Options include:

• Amnioreduction: Draining excess amniotic fluid from the recipient’s sac to reduce pressure on the babies and the placenta.
• Laser surgery: A specialist uses a laser to seal off the abnormal blood vessels in the placenta. This is the most effective treatment for severe TTTS.
• Early delivery: If you’re close to viability (usually around 24–26 weeks), your doctor may recommend delivering the babies early to stop the progression of TTTS.

Many moms describe the diagnosis of TTTS as devastating. One reader, Emily, shared: “I was 20 weeks pregnant with identical twins when my doctor told me they had TTTS. I went from celebrating the halfway point to preparing for surgery in 24 hours. The laser procedure was scary, but it saved my babies. They were born at 32 weeks and are now thriving.”

Selective intrauterine growth restriction (sIUGR)

sIUGR occurs when one twin grows significantly slower than the other. It’s more common in identical twins who share a placenta, but it can also happen in fraternal twins. At 20 weeks, your doctor will measure both babies’ growth during your ultrasound. If one baby is measuring smaller than expected, they’ll monitor you closely for signs of sIUGR.

There are three types of sIUGR, depending on the blood flow patterns in the placenta:

• Type I: The smaller baby has normal blood flow. This is the least severe type and often has a good outcome.
• Type II: The smaller baby has absent or reversed blood flow during part of the heartbeat cycle. This is more serious and increases the risk of stillbirth.
• Type III: The blood flow patterns are unpredictable and can change rapidly. This is the most severe type and often requires early delivery.

Treatment for sIUGR depends on the type and how far along you are. Your doctor may recommend:

• More frequent ultrasounds to monitor the babies’ growth and blood flow.
• Steroids to help the smaller baby’s lungs mature if early delivery is likely.
• Early delivery, usually between 32 and 34 weeks, if the smaller baby stops growing or shows signs of distress.

Preterm labor

At 20 weeks, your babies are still very small — about the size of bananas. Their lungs and other organs aren’t fully developed, so delivering this early would be extremely risky. However, preterm labor can start as early as 20 weeks in a twin pregnancy, especially if you have other risk factors like a short cervix or a history of preterm birth.

Signs of preterm labor include:

• Regular contractions (every 10 minutes or more).
• Pelvic pressure or a feeling that your babies are pushing down.
• A change in vaginal discharge (watery, mucus-like, or bloody).
• Low, dull backache.

If you notice these symptoms, call your doctor immediately. They may recommend:

• Hydration and rest to see if contractions stop.
• Medication to slow or stop labor (tocolytics).
• Steroids to help your babies’ lungs mature if delivery is likely.
• Hospitalization for close monitoring.

Cervical insufficiency

Your cervix is the opening to your uterus. During pregnancy, it stays closed and firm to keep your babies safe. But in some women, the cervix starts to open too early, increasing the risk of preterm birth. This is called cervical insufficiency, and it’s more common in twin pregnancies.

At 20 weeks, your doctor may measure your cervical length during an ultrasound. A short cervix (less than 25 mm) increases the risk of preterm birth. If your cervix is short, your doctor may recommend:

• A cervical cerclage: A stitch is placed in your cervix to help keep it closed. This is usually done between 12 and 14 weeks if you have a history of cervical insufficiency, or later if a short cervix is discovered during an ultrasound.
• Progesterone supplements: These hormones can help prevent preterm birth in some women with a short cervix.
• Bed rest: Your doctor may recommend limiting your activity to reduce pressure on your cervix.

Pre-eclampsia

Pre-eclampsia is a serious condition that involves high blood pressure and protein in your urine. It can develop as early as 20 weeks in a twin pregnancy, whereas it’s rare before 20 weeks in singletons. Symptoms include:

• Severe headaches.
• Vision changes (blurred vision, seeing spots).
• Sudden swelling in your hands, face, or feet.
• Upper abdominal pain (usually under your ribs on the right side).
• Nausea or vomiting (in the second half of pregnancy).

Pre-eclampsia is more common and often more severe in twin pregnancies. If you develop it, your doctor will monitor you closely and may recommend:

• Medication to lower your blood pressure.
• Steroids to help your babies’ lungs mature if early delivery is likely.
• Early delivery, usually between 34 and 37 weeks, depending on how severe your pre-eclampsia is.

What are the birth complications in a twin pregnancy?

Giving birth to twins is different from giving birth to one baby — and it comes with its own set of risks. About 75% of twins are born via C-section, but vaginal delivery is possible in some cases. Here’s what you need to know about the risks and complications of delivering twins.

Vaginal birth risks

Vaginal birth is possible for twins if:

• The first baby is head-down (cephalic).
• Both babies are in a good position for birth.
• You’ve had a previous vaginal delivery (though this isn’t required).
• You don’t have other risk factors, like placenta previa or a very large baby.

However, even if you plan a vaginal birth, complications can arise that require a C-section. These include:

• Fetal distress: One or both babies may show signs of distress during labor, such as an abnormal heart rate. This is more common with twins and may require an emergency C-section.
• Prolapsed umbilical cord: The umbilical cord slips through the cervix before the baby, cutting off their oxygen supply. This is a medical emergency and requires an immediate C-section.
• Breech or transverse position: If the second baby isn’t head-down after the first baby is born, your doctor may try to manually turn them or deliver them breech. If that’s not possible, a C-section may be needed.
• Placental abruption: The placenta detaches from the uterine wall before delivery, cutting off oxygen and nutrients to the babies. This is a medical emergency and requires an immediate C-section.
• Failure to progress: Labor stalls, and your cervix stops dilating. This is more common with twins, especially if you’re tired or dehydrated. Your doctor may recommend Pitocin to strengthen contractions or a C-section if labor doesn’t progress.

Many moms of twins plan for a vaginal birth but end up needing a C-section. One reader, Jessica, shared: “I was determined to deliver vaginally, but after 24 hours of labor, my second baby’s heart rate kept dropping. My doctor said, ‘We need to do a C-section — now.’ I was scared, but I trusted my team. My boys were born healthy, and that’s all that mattered.”

C-section risks

C-sections are major surgery, and they come with their own set of risks, especially in a twin pregnancy. These include:

• Infection: You’re at higher risk for infection in your uterus, incision, or urinary tract.
• Blood loss: C-sections involve more blood loss than vaginal births, and twin moms are already at higher risk for anemia.
• Blood clots: You’re at higher risk for deep vein thrombosis (DVT) or pulmonary embolism after a C-section.
• Injury to other organs: Rarely, the bladder, bowel, or other organs can be injured during surgery.
• Longer recovery: It can take 6–8 weeks to fully recover from a C-section, which can be challenging with two newborns.
• Breastfeeding challenges: Pain from your incision can make it harder to find a comfortable breastfeeding position.
• Future pregnancy risks: If you have a C-section, you’re at higher risk for placenta previa, placental abruption, and uterine rupture in future pregnancies.

Despite these risks, C-sections can be lifesaving for moms and babies. If you’re having a planned C-section, your doctor will discuss the risks and benefits with you ahead of time. If you need an emergency C-section, trust that your care team is making the best decision for you and your babies.

Preterm birth

About 60% of twins are born before 37 weeks, and 12% are born before 32 weeks. Preterm birth is the biggest risk factor for complications in twin pregnancies. The earlier your babies are born, the higher their risk of:

• Respiratory distress syndrome (RDS): Their lungs aren’t fully developed, so they may need help breathing.
• Intraventricular hemorrhage (IVH): Bleeding in the brain, which can lead to developmental delays.
• Necrotizing enterocolitis (NEC): A serious intestinal condition that can be life-threatening.
• Jaundice: Their livers aren’t fully developed, so they may have trouble processing bilirubin.
• Infections: Their immune systems aren’t fully developed, so they’re more susceptible to infections.
• Long-term developmental delays: Preterm babies are at higher risk for cerebral palsy, vision or hearing problems, and learning disabilities.

The good news is that neonatal care has come a long way. Even babies born as early as 24–26 weeks have a good chance of survival with the right care. If your babies are born early, they’ll likely spend time in the NICU. This can be scary, but remember: the NICU team is there to help your babies grow and thrive.

Postpartum hemorrhage

Postpartum hemorrhage (PPH) is heavy bleeding after delivery. It’s more common in twin pregnancies because:

• Your uterus has to stretch more to accommodate two babies, so it may not contract as well after delivery.
• You’re at higher risk for placental problems, like placenta previa or placental abruption.
• You’re more likely to have a C-section, which increases the risk of PPH.

PPH is a medical emergency. Signs include:

• Heavy bleeding (soaking through a pad in an hour).
• Passing large blood clots (bigger than a golf ball).
• Dizziness, lightheadedness, or fainting.
• A rapid heart rate.

If you experience these symptoms, call your doctor or go to the emergency room immediately. Treatment for PPH may include:

• Medication to help your uterus contract.
• A blood transfusion if you’ve lost a lot of blood.
• Surgery to stop the bleeding, such as a hysterectomy in severe cases.

What are the most common risks associated with a twin pregnancy?

While every twin pregnancy is unique, some risks are more common than others. Here’s a rundown of the most frequent complications, along with how often they occur and what your care team will do to manage them.

Risk	How common is it?	What happens?	How is it managed?
Preterm birth	60% of twins are born before 37 weeks; 12% before 32 weeks	Babies are born too early, increasing the risk of health problems.	Steroids to help babies’ lungs mature, tocolytics to slow labor, bed rest, hospitalization.
Low birth weight	About 50% of twins weigh less than 5.5 pounds at birth	Babies may need help breathing, eating, or staying warm.	NICU care, feeding support, monitoring for complications.
Gestational diabetes	Up to 15% of twin pregnancies (vs. 6–9% of singletons)	High blood sugar can cause babies to grow too large, increasing the risk of birth injuries and C-section.	Diet and exercise, blood sugar monitoring, medication if needed.
Pre-eclampsia	Up to 30% of twin pregnancies (vs. 5–8% of singletons)	High blood pressure and protein in urine can lead to seizures, stroke, or organ damage.	Blood pressure medication, bed rest, early delivery if severe. Editor's pick for this topic Prenatal pick Ritual — Ritual Essential Prenatal Choline + DHA + folate from methylfolate (not synthetic). $39Check prenatal → Prenatal pick Nordic Naturals — Nordic Naturals Prenatal DHA (Strawberry Softgels) Premium fish-oil DHA in strawberry softgels — gentle on the stomach. $55Check prenatal → Not sure about the label on Twin Pregnancy Risks products? Snap the ingredients list and SafeFilter checks every ingredient for your stage — only 3 free scans this month, then you're locked until reset. Unlimited from $7/mo or $50/yr. Use a free scan See $7 / $50 plans Informational only — not medical advice. About the Author When Shubhra Mishra was expecting her first child in 2016, she was overwhelmed by conflicting food advice — one site said yes, another said never. By the time her second baby arrived in 2019, she realized millions of mothers face the same confusion. That sparked a five-year journey through clinical nutrition papers, cultural diets, and expert conversations — all leading to BumpBites: a calm, compassionate space where science meets everyday motherhood. Her long-term vision is to build a global community ensuring safe, supported, and free deliveriesfor every mother — because no woman should face pregnancy alone or uninformed. 🌿 🌍 Stand with mothers, shape safer guidance Join a small circle of experts who review BumpBites articles so expecting parents everywhere can decide with confidence. Apply via web formoremail contact@bumpbites.health ⚠️ Always consult your doctor for medical advice. This content is informational only. Long-form pregnancy guides Hand-curated deep-dive guides — go beyond the article above. Complete Pregnancy Nutrition Master GuideTrimester-by-trimester pregnancy nutrition — the orchestrating hub. Foods to Avoid in PregnancyThe full pregnancy food-avoidance list with the science behind each. First Trimester Survival GuideEating through nausea, fatigue + aversions in T1. More Pregnancy guides Best Twin Pregnancy Sleep Positions for Comfort and Safety Twin Pregnancy Symptoms in First Trimester How Much Weight Should You Gain During a Twin Pregnancy? Twin-twin transfusion syndrome: Stages I‑V & GA‑adjusted care Twin Ultrasound Schedule: What to Expect and When to Book tylenol before vs after vaccine for baby Type 1 Diabetes Pregnancy: Titrate Basal‑Bolus Avoid Hypoglycemia U‑shaped vs C‑shaped vs wedge pillows: Comparison and advice ultrasound at 9 weeks of pregnancy Ultrasound in 16 Week Pregnancy Anatomy Scan See all Pregnancy guides → ⬆️ Back to Top Recommended picks Prenatal pick Ritual — Ritual Essential Prenatal Choline + DHA + folate from methylfolate (not synthetic). $39Check prenatal → Prenatal pick Nordic Naturals — Nordic Naturals Prenatal DHA (Strawberry Softgels) Premium fish-oil DHA in strawberry softgels — gentle on the stomach. $55Check prenatal →