Twin Pregnancy in IVF

Twin pregnancies are seen at a higher rate in IVF than in normal pregnancies. The reason for this is the number of embryos transferred. The answer to the question of whether twin pregnancies are possible in IVF is actually directly proportional to the embryos transferred. Pregnancy and pregnancy-related risks increase for expectant mothers who are expecting twins or more babies. In addition, these risks also apply to babies. The risk of death and disability in babies also increases.

Currently, about one in six in vitro fertilization (IVF) pregnancies result in twins. Other fertility treatments, such as clomiphene citrate (tablets used to induce ovulation) and intrauterine insemination (IUI), can also increase the risk of twin pregnancies with IVF. Multiple pregnancies and births carry significant risks for children.

Possible risks of twin pregnancy in IVF

Risks during pregnancy

• The risk of early and late miscarriage is higher compared to singleton pregnancies.
• 20% of mothers carrying twins have induced high blood pressure (hypertension), compared to only 1-5% of singleton mothers.
• The risk of preeclampsia is 30% in twin pregnancies and 2-10% in singleton pregnancies.
• The chance of women pregnant with twins developing gestational diabetes is up to 12%, compared to only 4% for mothers with singleton pregnancies. Although the risks to the mother are quite mild, gestational diabetes can increase the risk of death to the unborn child or the newborn baby.

Risks during or after birth

• Cesarean delivery is more common in twin pregnancies because the risk of complications is higher.
• There is an increased risk of problems such as hemorrhage and anemia.
• The risk of a twin pregnancy or maternal death during childbirth is twice as high.
• New mothers may be more vulnerable to mental health problems such as stress and depression.
• Even less serious problems can cause the mother to spend more time in hospital than usual. Women expecting twins may have to spend the last weeks of pregnancy in hospital.

How to prevent twin pregnancy in IVF?

In our country, the risk of multiple pregnancy is legally controlled. Twin pregnancy occurs as a result of more than one embryo transfer. If the woman is under 35 years old, only one embryo is transferred if it is the first two IVF attempts. Apart from this, a maximum of 2 embryos are transferred. In this way, the risk of multiple pregnancy is prevented.

Multiple pregnancy problems

In the case of multiple pregnancies, high blood pressure, diabetes, anemia, urinary tract infections and pregnancy-related symptoms are experienced more frequently. In multiple pregnancies, the risk of chromosomal problems and health problems for the babies increases. Twin pregnancies are becoming more common in IVF among women undergoing infertility treatment today. The health risk for twins and triplets is significantly higher compared to singletons, as multiple babies tend to be premature and low weight. The risk of early and late miscarriage is higher in twins than in singleton pregnancies. The chance of a single embryo splitting, resulting in identical twins, is higher after IVF, but the reason for this is unknown. Therefore, it is possible to have identical twins with a single transplanted embryo or triplets from two embryos.

The vast majority of these identical babies share a placenta and are at higher risk than non-twins for complications during pregnancy, such as twin-to-twin transfusion syndrome, which can lead to health problems and death. If a multiple pregnancy is considered a serious health threat to the mother or baby, the clinician may recommend a fetal reduction to increase the chance of survival and a healthy outcome for the remaining fetus, while also reducing the chance of losing the pregnancy altogether. The goal of all infertility treatments is to have a living, healthy baby.

• Many twins and triplets are born prematurely, meaning that they are born before the normal time for healthy singleton babies:
• Singleton babies are usually born at around 40 weeks of pregnancy and have normal birth weights.
• At least half of twin pregnancies in IVF are born at 37 weeks premature with low birth weights and are at risk of serious health problems and death. Many are born at 35 weeks premature, when they usually need neonatal care. Their birth weight is approximately 800–1000 g lower than singleton pregnancies.
• More than 90% of triplets are born before 37 weeks, and many are born so early that they may have long-term, serious health problems or die shortly after birth.