Twin Pregnancy Complications

Twin Pregnancy Complications

Twin pregnancy complications

So you’re having twins, what an exciting time. You may be concerned about the complications that can arise during a your pregnancy. When it comes to having twins and pregnancy complications it is important to be aware but not to worry or obsess about the what ifs.


Concentrate on the now and do the best you can to have a healthy pregnancy through diet, rest and specialized care.


Though many women expecting multiples will have little to no problems, all multiple pregnancies are classed high-risk as the possibility of complications increases.


Be aware of the possible health issues in a multiple pregnancy. Knowing the signs could be extremely helpful for early detection.

Twin Pregnancy Miscarriage


Pregnancy bleeding in the first trimester can sometimes indicate a miscarriage. If one twin is lost this is known as Vanishing Twin Syndrome . The twin who has seemingly vanished is usually reabsorbed into the mother or miscarried.


Symptoms of Miscarriage

Symptoms include vaginal bleeding and severe abdominal pain which can also indicate an ectopic pregnancy. An ectopic pregnancy is when a baby implants outside the uterus and this is life threatening.


Placental Sharing – Monochorionic Twins

The term Monochorionic Twins is used when identical twins share one placenta, fraternal twins can sometimes but rarely share one to but it’s when the two fuse together. With most twin pregnancies fraternal twins will have their every own placenta, this is called dichorionic twins. Sometimes identical twins will have separate placentas.


Sharing a placenta carries more twin pregnancy complications, as two babies are growing and feeding off one placenta and the oxygen, blood flow and nutrients may not be distributed evenly, this is known as unequal placenta sharing. Blood circulations are connected through blood vessels within the placenta, the blood may be passed disproportionately from one baby to the other, and this can lead to Twin to Twin Transfusion Syndrome (TTTS).


More commonly birth weigh differences will occur with placenta sharing.

My Monochorionic Twins Story


My twin girls who are identical shared a placenta during my twin pregnancy. I was watched very closely with ultrasounds left right and center, which was great for the many ultrasound pictures I got. The ultrasound was to monitor the growth of each baby. My girls were born at 38 weeks and 2 days naturally with a slight difference in weight. Being healthy little girls, I was able to go home the next day. I feel very fortunate not to have any serious twin pregnancy complications.

A mother having twins whether they share a placenta or not, are at a higher risk for twin pregnancy complications such as placenta previa and placenta abruption than a mother carrying one baby.

Monoamnionic Monochorionic or Mo-Mo Twins


A rear condition affecting 1% of twin pregnancies, Mo-Mo twins occurs when identical (monozygotic) twins share a placenta and an amniotic sac. An ultrasound is the only way this can be diagnosed. The concern is the umbilical cords can become entangled cutting off the supply of oxygen and nutrients. The only cure is to deliver the babies.


Preeclampsia also known as Pregnancy Induced Hypertension (PIH) or Toxemia is more common during a twin pregnancy. About 10-20% of women expecting multiples will experience preeclampsia either mildly or severely.



Symptoms are high blood pressure being 140/90 and large amounts of protein in the urine which occurs from 20 weeks gestation. Other signs to look for are swelling of your hands, feet and face. This could result in Preterm Labor or HELLP Syndrome if untreated.

What is HELLP Syndrome?


It is a life threatening liver disorder which is a severe case of preeclampsia.

Intrauterine Growth Restriction (IUGR)

Intrauterine Growth Restriction is a baby measuring 10% smaller for gestational age. Things that can cause this are:

  • Poor blood circulation within the placenta
  • An infection in the placenta
  • Multiple Pregnancy

IUGR more commonly happens in twin pregnancies (or more) than with a singleton one. The growth rate in twin gestation starts to slow at about 31 weeks, contributing to IUGR. In some cases it can be serious and can cause preterm labor.

Gestational Diabetes

All pregnant women will have a test done for Gestational Diabetes. If there is a family history of diabetes, you are overweight or are over a certain age you have this test done earlier on during your pregnancy.

The test measures your blood sugar and if diagnosed will usually only last for the duration of the pregnancy. Having a twin pregnancy can increase your chance of gestational diabetes.

Most expectant mothers will need to adjust their diet and others may need to have insulin.

Preterm Labor

A common twin pregnancy complication is premature labor.

A preterm birth is babies being born before the 37th week. Though twins are often born prematurely there are also many expectant mothers who go full term which is at 38 weeks and above. 

Conjoined Twins

Conjoined twins, aka Siamese twins, is a very rare twin pregnancy complication with about 1 in every 200,000 births. Occurring only with identical twins as the fertilized egg does not split completely, depending on where the split happens will determine their survival.

About 25% of conjoined twins will survive, most will be still born or won’t make it past the first 24 hours. This is due to vital organs being connected and viability in the real world is not possible.

Have you got any further questions, then check out our FAQs for a Twin Pregnancy

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