A healthy twin pregnancy comes down to gaining the right amount of weight, eating significantly more than you would with one baby, staying on top of more frequent prenatal visits, and knowing which warning signs need immediate attention. Twin pregnancies carry higher risks for preterm birth, preeclampsia, and gestational diabetes, but the right monitoring and self-care make a real difference in outcomes for both you and your babies.
How Much Weight to Gain
Weight gain targets for twins are substantially higher than for a single baby, and they vary based on your pre-pregnancy BMI. A large study published in JAMA Network Open identified optimal ranges by 36 weeks of gestation: women at a normal weight do best gaining roughly 15 to 25 kg (33 to 55 pounds), while those who are overweight before pregnancy should aim for a similar range of 15 to 25 kg. For women with class 1 obesity, the target drops to about 10 to 20 kg (22 to 44 pounds), and for class 2 obesity, roughly 7.5 to 17.5 kg (17 to 39 pounds).
Much of this gain happens in the second and third trimesters, when fetal growth accelerates. Gaining too little is linked to lower birth weights and earlier delivery, while gaining too much increases the risk of complications like preeclampsia and gestational diabetes. Your provider will likely track your weight more closely than in a singleton pregnancy, and early, steady gain in the first trimester matters more than it does with one baby.
Calorie and Protein Needs
Growing two babies requires a lot more fuel. Research estimates that women pregnant with twins need an additional 700 calories per day in the second and third trimesters compared to the first trimester. One well-known nutrition program recommends an extra 1,000 calories per day after week 20, along with 50 grams of additional protein (roughly 500 calories and 25 grams of protein per baby). To put that in perspective, third-trimester intake in twin pregnancies averages around 2,900 calories per day, up from about 2,250 in the first trimester, a 29% increase.
These numbers are higher than singleton guidelines, which call for only about 275 extra calories per day spread across the entire pregnancy. The practical takeaway: you need to eat substantially more, and protein is especially important. Think in terms of adding nutrient-dense meals and snacks rather than simply eating more of what you already eat. Good sources include eggs, Greek yogurt, lean meats, legumes, and nuts. Many women carrying twins find it easier to eat five or six smaller meals a day rather than three large ones, especially as the uterus grows and compresses the stomach.
Supplements Worth Paying Attention To
A standard prenatal vitamin is the starting point, but twin pregnancies place higher demands on certain nutrients. Folic acid is critical in the first trimester for preventing neural tube defects, and most guidelines recommend at least 1 mg daily for multiple gestations (compared to 0.4 mg for singletons). Iron needs also climb because your blood volume expands more dramatically with twins, raising the risk of anemia. Your provider will likely check your iron levels more than once and may recommend a higher-dose supplement if levels dip.
Calcium, vitamin D, and omega-3 fatty acids all support fetal bone and brain development and become harder to get in sufficient amounts from food alone when you’re growing two babies. If nausea makes it hard to keep prenatal vitamins down in the first trimester, talk to your provider about alternative formulations or timing.
Why Your Type of Twins Matters
One of the most important things you’ll learn early on is whether your twins are dichorionic (each baby has its own placenta) or monochorionic (they share a single placenta). This distinction shapes your entire monitoring schedule and risk profile.
Monochorionic twins face unique risks because shared blood vessels in the placenta can cause uneven blood flow between the babies. The most serious version of this is Twin-to-Twin Transfusion Syndrome (TTTS), where one baby gets too much blood and the other too little. TTTS is diagnosed on ultrasound when one twin has too much amniotic fluid and the other has too little. Nearly half of women whose pregnancies develop TTTS experience symptoms beforehand: rapid weight gain, a feeling of sudden swelling, pain, or contractions. Reporting these symptoms quickly can lead to earlier diagnosis and treatment.
Because of these risks, monochorionic twins need ultrasound surveillance every two weeks starting at 16 weeks. Research confirms that longer intervals between scans are associated with worse outcomes. Dichorionic twins are generally monitored less frequently, typically every three to four weeks, though your provider may adjust this based on your specific situation.
Screening for Preterm Birth
About 60% of twins are born before 37 weeks, making preterm birth the single biggest concern in a twin pregnancy. Cervical length measurement during the second trimester is one of the strongest predictors of when delivery might happen. In twin pregnancies, a cervix shorter than 25 mm is the threshold for concern (compared to 15 mm in singletons). A cervix shorter than 20 mm at midpregnancy is associated with a 42% chance of delivering before 32 weeks.
Your provider will likely measure your cervix by ultrasound at your mid-pregnancy anatomy scan and possibly at additional visits. Knowing your cervical length helps your care team decide whether interventions like progesterone or closer monitoring are needed. Watch for signs of preterm labor yourself: regular tightening or contractions, pelvic pressure, low back pain that doesn’t go away, or any change in vaginal discharge.
Gestational Diabetes and Preeclampsia
The risk of gestational diabetes in twin pregnancies is more than double that of singleton pregnancies. Screening involves the same glucose challenge test used for all pregnancies, typically between 24 and 28 weeks. If you’re diagnosed, treatment follows the same approach regardless of how many babies you’re carrying: dietary changes, blood sugar monitoring, and sometimes medication. Keeping blood sugar controlled reduces the risk of oversized babies and delivery complications.
Preeclampsia, a condition involving high blood pressure and organ stress, is also more common with twins. Low-dose aspirin started before 16 weeks of gestation can reduce the risk. A multicenter study found that 160 mg daily was more effective in twin pregnancies than the 80 to 100 mg dose often used for singletons, cutting the risk of preeclampsia by about 37% with no increase in complications. Your provider may recommend aspirin prophylaxis even if you have no other risk factors, simply because carrying twins is a risk factor on its own.
Staying Active Safely
Exercise during a twin pregnancy is not off-limits, but the guidance is less specific than for singleton pregnancies. Most providers recommend staying moderately active, using the “talk test” as a gauge: if you can carry on a conversation during exercise, the intensity is appropriate. Walking, swimming, and prenatal yoga are commonly encouraged. Avoid contact sports and activities with a risk of falls.
After 28 weeks, twin pregnancies are considered a relative contraindication to exercise, meaning you should check in with your provider about what’s still safe. In practice, many women find that physical limitations naturally scale back activity in the third trimester anyway. A survey of women with multifetal pregnancies found that 74% received only vague advice from providers like “listen to your body,” so don’t hesitate to ask for specifics about what activities are and aren’t appropriate for your situation.
When Delivery Typically Happens
The ideal delivery timing depends on your type of twins. Research suggests that uncomplicated monochorionic twins do best when delivered at or after 36 weeks, while dichorionic twins can safely wait until 37 weeks or beyond. These targets balance the declining risk of prematurity-related problems against the increasing risk of stillbirth and placental issues that comes with longer gestation in twin pregnancies.
Most providers will schedule a planned delivery date even if everything is going smoothly, because the risks of continuing the pregnancy past these windows begin to outweigh the benefits. Whether you deliver vaginally or by cesarean depends on factors like the position of the first baby, your medical history, and how the pregnancy has progressed. Many twin pregnancies result in vaginal delivery when the first baby is head-down, though you should be prepared for the possibility that plans may shift during labor.
Day-to-Day Practical Tips
Rest becomes a real priority, especially after the second trimester. Your body is doing roughly twice the work of a singleton pregnancy, and fatigue is not a sign of weakness. Sleep on your side with a pillow between your knees to reduce pressure on your back and improve blood flow to the babies. Staying hydrated is important for maintaining amniotic fluid levels and reducing the risk of contractions.
Meal prep and batch cooking in the second trimester can save you during the third, when standing in a kitchen for long stretches becomes harder. If you’re working, talk to your employer about accommodations earlier than you might with a singleton pregnancy. Many women carrying twins begin leave or reduce hours around 32 to 34 weeks, though this varies widely. Keep a written list of warning signs (contractions, sudden swelling, visual changes, severe headache, reduced fetal movement) on your phone so you don’t have to rely on memory during a stressful moment.