Ending a Twin Pregnancy: The Story of the Twin Who Survived

Selective termination refers to the elimination of an abnormal fetus, whereas multifetal pregnancy reduction denotes the termination of one or more members of twin or higher-order multiple birth set to decrease the risks usually posed by these pregnancies. When a serious physical condition is detected in a twin pregnancy, the procedure has been used to eliminate that fetus. In contrast with the foregoing, there have been cases in which selective termination reduced two healthy fetuses to one when parents wanted just one more child in their family.

I have always wondered if surviving twins whose healthy co-twin was selectively terminated for this reason (and or related reasons) might feel anger, resentment, and or sadness at having being denied the benefits that twinship offers. Surprisingly, I have never come across studies or case reports that have examined this. That changed unexpectedly.

In January 2021, a 54-year-old woman contacted me to reveal her personal story. She wondered if I would be interested in the “experience of a twin who survived an attempted (or at least partially successful) termination.” I will call her TS for “twin survivor” to preserve her privacy. We communicated by telephone and over a series of email exchanges.

In 1966, TS’s mother, who was 32 years of age, discovered she was pregnant for the fourth time. It is unlikely that TS’s mother knew that she was carrying twins, but given the family’s financial constraints, they were unable to raise another child. A family friend who was a chemist gave her mother a substance to end the pregnancy. (Pregnancy termination was illegal in the United Kingdom at that time.) It turned out that only one twin fetus was aborted, and the pregnancy continued.

Even as a young child, TS felt “an innate and overwhelming sense of distress.” It is easy to explain these feelings as due to her lost twinship; however, scientific evidence does not favor such interpretations that would require prenatal knowledge of twinship. Research shows that low oxygen tension in fetal blood, as well as pregnanolone and prostaglandin D2 provided by the placenta, keep fetuses sedated (see Lagercrantz, & Changeux, 2009 below).

The truth about her birth was kept hidden until TS was told by a cousin when she was 13 years old. Her cousin assumed that TS knew this fact of her birth. She recalls feeling shocked and in disbelief. At the same time, she believes that she gained an understanding of why she had always felt different from others. She also felt that she gained new insights into her childhood thoughts and experiences.

As I indicated above, connections between prenatal twin loss and adolescent-adult behaviors cannot be conclusively drawn. However, some parents of young singleton twins have observed a strong desire for physical closeness in their children. It is not unreasonable to speculate that these observations could reflect the twins’ prenatal contact, scientists must remain open to the possibility that young surviving twins miss something for which they lack words and understanding. It is unclear how these observations could be studied.

Today, TS is not bitter, angry, or resentful, explaining that she tries to justify her mother’s decision. She felt loved as a child and beyond, and feels privileged to live life. Still, as a surviving twin, she feels sad and melancholy.

Selective Termination: The Controversies. A 1981 termination of a twin fetus with trisomy 21 (Down syndrome) at 17 weeks into the pregnancy led to an intense discussion of ethical and moral questions among physicians. There was the risk of damaging or killing the healthy fetus. One physician who learned of the case felt that the adoption of the Down's infant would have been a more prudent choice than termination. Of course, such decisions are never easy for the families involved. It is, however, difficult to understand why some families with two healthy twin fetuses would elect to abort one of them, especially if the twins were conceived by assisted reproductive techniques (ART).

It is well known that ART often yields more than one fetus and most couples who seek such interventions can cover its cost. I am grateful to TS for sharing her story, but we cannot know how representative her perspectives might be. Understanding the impact of twin loss due to multifetal reduction will only be possible if other individuals from such pregnancies are willing to reveal their thoughts and experiences.