Twin Pregnancy Complications: Risks for Mother and Baby

Twin pregnancies carry a higher risk of complications for both the mother and babies than singleton pregnancies, which is why they are classified as high-risk pregnancies and require closer medical monitoring. Research from the WHO Multicountry Survey found that 37.1% of twin pregnancies result in preterm birth, and twins are significantly more likely to experience low birth weight, NICU admission, and other adverse outcomes compared with singletons (1).

While many women with twin pregnancies deliver healthy babies, carrying two babies places extra demands on the mother’s body and increases the likelihood of complications. In this article, we’ll explore the most common complications of twin pregnancy, the risks they pose to both mother and babies, factors that increase the likelihood of complications with twins, and the medical strategies used to manage them effectively.

Why Twin and Multiple Pregnancies Are a Concern?

A multiple or a twin pregnancy may put your health at risk. The chances of developing gestational diabetes, preeclampsia, and other pregnancy-related complications are higher in the case of multiple pregnancies due to the greater load on the mother’s body and immune system with two or three babies (2).

Twin Pregnancy Complications

The chances of complications during twin pregnancy are higher when the twins share the same placenta. Dichorionic diamniotic twins complications (twins not sharing the same placenta) are not that severe as compared to monochorionic diamniotic twins complications (twins sharing the same placenta).

Here are some twin pregnancy risks you need to watch out for (3):

1. High Blood Pressure

A rise in the level of the blood pressure is 2-3 times more likely in you if you are expecting twins (or more babies) than you if you expecting one.

2. Preeclampsia

Preeclampsia is another risks of twin pregnancy that you might have to face. When you are expecting more than one baby, the strain on your placenta is more compared to a single baby (4).

If you are expecting twins, your doctor will closely monitor your blood pressure levels and test your urine to diagnose preeclampsia symptoms, if any, at antenatal appointments. The doctor might also prescribe aspirin-type drugs which will be started in the first trimester and might be continued later too to reduce your blood pressure levels and prevent preeclampsia. The screening is advised in the following cases:

• If this is your first pregnancy
• If you are above 40 years of age
• If your BMI is 35 or more than that
• If there is a history of preeclampsia in your family
• If you became pregnant after a gap of 10 years

3. Gestational Diabetes

The risk of gestational diabetes is also higher with twin or multiple pregnancies. The doctor will check your urine to know your blood sugar levels. A glucose tolerance test will be prescribed if your doctor suspects that you have diabetes (5).

4. Anaemia

Your iron levels may drop due to an increased level of blood flow and the growing needs of the babies, leading to anaemia (6). You need to be extra careful about your iron levels as the drop will make you feel tired. Your doctor will recommend iron supplements. However, make sure you include vegetables that are rich in iron in your diet as well. Anaemia is more common in mothers expecting more than one baby. Your doctor will closely monitor you and also give your more blood tests if required.

5. Obstetric Cholestasis

This rare condition is caused by oestrogen and progesterone hormones and it affects your liver. When you are expecting twin (or more) babies, the secretion levels of these pregnancy hormones go up and lead to obstetric cholestasis. Symptoms include severe itching (7).

6. Placental Abruption

This is a serious condition that happens when your placenta detaches from the uterine wall before the delivery (8). This is one of the most serious twin pregnancy complications the third trimester poses.

7. Postpartum Hemorrhage

Women carrying twins are at a higher risk of postpartum hemorrhage, which refers to excessive bleeding after childbirth. This happens because the uterus becomes more stretched than usual when carrying two babies, making it harder for the uterine muscles to contract effectively after delivery (9).

Complications That Can Affect the Babies

Here are some of the complications which may affect the babies in a twin pregnancy.

1. Foetal Restriction

Retarded growth of the babies, where one or both the babies do not grow as much as they should and this can lead to complications both during birth and labour (10). However, this is something that you do not have to worry about much. Most twins are born small but they are healthy. Your doctor will conduct regular scans to monitor the growth of your twins and this would help in detecting all kinds of problems.

2. TTTS or Twin to Twin Transfusion Syndrome

This happens when one baby shares the other baby’s blood supply. The condition is rare but can lead to serious problems. This is a common complication among monochorionic diamniotic twins and it affects as much as 15% of the identical twins. One of the babies gets too much blood while the other gets much less than what is required. As a result, the baby donating blood is smaller and looks anaemic too due to the lack of blood. A higher volume of blood strains the heart of the other baby and this can lead to a heart failure (11).

3. Entangled Umbilical Cords

Monoamniotic Monochorionic twins are twins with entangled umbilical cords. This is a rare condition which prevents the flow of oxygen and nutrients to the developing babies (12).

4. Congenital Abnormalities

The risk of congenital abnormalities in the babies is more in the case of multiple pregnancies.

5. Premature Birth

Twins are more likely to be born prematurely than single babies. A premature birth occurs when babies are delivered before 37 weeks of pregnancy (13). Because twins often have less space to grow in the womb, labor may start earlier than expected or doctors may recommend an early delivery if complications arise.

What Are the Chances and Risks of Premature Delivery?

The risk of preterm labour and miscarriage is also higher and so are the chances and risks of premature delivery. However, it is hard to say how much higher this risk exactly is. This is because early miscarriages are hardly easily identified.  If you do face a premature delivery, you can’t take your babies home immediately. The extent to which they need to stay in the hospital will depend on how premature they are.

In the cases of twins, full-term is 37 weeks. More than 50% of the twins are born before the 37th week and less than 10% are born before the 32nd week.

What Are the Chances of Having a Miscarriage?

The chance of miscarriage with twins are higher compared to when you are carrying a single child. It is common for miscarriages to happen during the initial twelve weeks, whether it is single or multiple pregnancies.

Chances and Risks of Stillbirth

The risks of stillbirth are higher in cases of multiple pregnancies. Losing the baby in the first month after the birth is also possible.

In case of multiple pregnancies, the risk of the complications including stillbirth increases just after the completion of the 38th week. This is the reason why doctors suggest induction or a caesarean if you do not deliver the twins by the 38th week of your pregnancy.

The rate of stillbirth is more in the case of identical twin babies who share the same placenta. The mother is often advised to deliver earlier, by the 37th week, in such cases.

Vanishing Twin Syndrome

In many cases, one baby is lost and if you lose the baby within the first trimester, the development of the other baby is usually not affected. The lost foetus is reabsorbed completely, a condition known as vanishing twin syndrome, and you might not experience any symptoms. The percentage range of this syndrome is 21-30 percent, meaning it is quite common (14).

Preventing Complications of Twin or Multiple Pregnancies

Your behaviour or lifestyle has very little to do as far as multiple or twin pregnancy is concerned. Getting the early confirmation that you are carrying twins or triplets will give your doctor the chance to prevent and treat all twin or triplets pregnancy risks that may arise.

Always stay hydrated and well-nourished. Never miss even a single prenatal appointment with your gynaecologists and make sure to abide by all the instructions given by your healthcare provider. Keep the following tips in mind to prevent any sort of complications.

Tips to Remember When Pregnant With Twins

The odds of conceiving twins cannot be determined exactly in any case. Keep the following tips in mind to keep yourself healthy with multiple pregnancies (15):

• Maintaining a healthy weight is crucial in the case of twin pregnancies. The weight you can gain before 20 weeks is crucial. Your weight should be such that it reduces the risk of a low birth weight and premature birth.
• Your iron levels are most likely to drop as the blood flow increases in the case of twin pregnancies. This can lead to anaemia and this will be harmful to both you and the babies. Take iron supplements regularly, after consulting your doctor.
• Going for antenatal appointments is very important. Your doctor will conduct regular check-ups and ensure that you and your babies are healthy.

FAQs

1. Can one twin grow slower than the other?

Yes, one twin may grow more slowly than the other, a condition known as selective fetal growth restriction (sFGR). Regular ultrasounds help doctors monitor the babies’ growth and identify any concerns early.

2. Do all twins need to stay in the NICU after birth?

No, not all twins require neonatal intensive care. However, twins are more likely to need NICU support if they are born prematurely, have a low birth weight, or experience health complications after delivery.

Knowing the risks and complications of multiple pregnancies will go a long way in alleviating any concerns you may have about carrying multiples. Stay aware and do make sure you speak to your doctor if you are worried at any point in your pregnancies.

Also Read:

Types of Twins
Twins with IVF
Twin Pregnancy Precautions & Care

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Sources References

1. PubMed – Perinatal outcomes in twin pregnancies complicated by maternal morbidity: evidence from the WHO Multicountry Survey on Maternal and Newborn Health

2. Cleveland Clinic – Expecting Twins or Triplets

3. Johns Hopkins Medicine – Complications of Multiple Pregnancy

4. Cleveland Clinic – Preeclampsia

5. Cleveland Clinic – Gestational Diabetes

6. Cleveland Clinic – Anemia

7. Cleveland Clinic – Cholestasis of Pregnancy

8. Cleveland Clinic – Placental Abruption

9. Cleveland Clinic – Postpartum Hemorrhage

10. Tommy’s – Fetal growth restriction (Intrauterine growth restriction)

11. Cleveland Clinic – Twin-to-Twin Transfusion Syndrome

12. PubMed Central – Cord Entanglement in Monochorionic Diamniotic Twin Pregnancy: A Rare Diagnostic and Clinical Challenge

13. Cleveland Clinic – Preterm Birth

14. Cleveland Clinic – Vanishing Twin Syndrome

15. March of Dimes – Being pregnant with twins, triplets and other multiples