The Impact of Prematurity in Twins and Multiples

Premature Twins

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How many weeks? It's one of the first questions people ask about twins and multiples. Prematurity is a risk that a majority of multiples face, and the consequences of an early birth vary from minuscule to life-threatening. The March of Dimes estimates that more than half of twins and nearly all triplets, quadruplets, and higher-order multiples are born preterm, or before the 37th week of pregnancy. The earlier the birth, the greater the risk of complications for the premature babies (sometimes called "preemies").

While advances in medical technology have greatly improved the outlook for premature infants, the global number of premature births has also increased, making prematurity the leading cause of newborn deaths and the second-leading cause of death in children under the age of 5. Worldwide, one in 10 infants worldwide is born prematurely.

The Consequences of Premature Birth

Because of the increased risk, it's important for parents of multiples to understand the potential impact that prematurity can hold for children. Prematurity will touch families' lives in varying degrees. For some, it may mean only a brief hospitalization. Yet others endure extended hospital stays after their babies arrive. In some cases, the medical problems and issues are only a factor in the first few weeks after birth, while other cases have lifelong consequences.

The determining factor is often the timing of the birth. Babies born closer to their due date are less likely to have serious problems because their organs have had more time to develop in the womb.

Immediate Medical Concerns

The womb serves as the perfect place for babies to develop. When babies are born too early, their organs are immature and not ready to function in "the outside world."

Prematurity impacts every vital organ in the body.

  • Lungs: Babies, primarily those born before 32 weeks, have trouble breathing air. Respiratory distress syndrome can be treated with artificial breathing assistance and with a surfactant, a substance that helps immature lungs expand. Sometimes the life-saving measures used to treat lung deficiencies in preemies result in chronic lung disease or bronchopulmonary dysplasia (BPD) and may require ongoing treatment.
  • Brain: Intraventricular hemorrhage (IVH) is bleeding in the brain that mainly affects babies born before 32 weeks or babies who have experienced stress from another condition of prematurity, such as respiratory distress.It can cause damage to the brain or decreased drainage of spinal fluid leading to a buildup of too much fluid in and around the brain (hydrocephalus).
  • Heart: In the womb, the ductus arteriosus allows babies to receive oxygen through the umbilical cord, bypassing the lungs. At birth, this blood vessel is supposed to close. Premature infants can develop patent ductus arteriosus, which causes abnormal blood flow between major blood vessels surrounding the heart. It can lead to organ malfunction throughout the body, especially the lungs, and may be fatal.
  • Intestines: Accustomed to receiving nutrition from the placenta via the umbilical cord, premature babies' digestive systems are not ready to process food. Newborns can develop an inflammation of the lining of the intestines or more severe infections. Necrotizing enterocolitis (NEC) can result in widespread infection or localized bowel damage or tissue death that can lead to obstruction and may require surgery to correct.
  • Eyes: Many premature infants develop problems with their eyes because the blood vessels of the retina are not completely developed. Retinopathy of Prematurity (ROP) results when the fragile blood vessels' development is interrupted by premature birth and they stop growing or grow abnormally. Severe cases can lead to vision impairment or blindness. Sometimes the condition can be treated immediately with surgery or laser therapy. Yet most ROP cases are mild and will resolve on their own over time.

These conditions represent the "worst case scenarios" faced by extremely premature infants, born prior to 28 weeks' gestation. In most cases, premature multiples who receive advanced medical care in modern hospital facilities are able to overcome the challenges of their early start.

Ongoing Medical Concerns

After the initial critical phase following a preterm birth, when the focus is on survival, the consequences of prematurity may not be fully known. Some of the long-term complications may not become apparent until the multiples start school. It can be worrisome for parents, who are already stressed by the challenge of caring for more than one baby.

A 2008 medical study raised alarms about increased problems for preemies throughout their lifetime. Researchers from Duke University Medical Center and University of Bergen followed over one million babies born in Norway between 1967-1988. They concluded that premature infants are:

  • More likely to die during childhood
  • Less likely to have children of their own as adults
  • Significantly less likely to finish high school or complete college

The researchers attributed these outcomes to medical problems that result from premature birth as well as a socioeconomic status that is lowered due to medical conditions. However, their data did not include twins or multiples, and the individuals in the study were born more than 30 years ago and would not have had access to the medical technology that helps so many premature infants today. It's important to keep this study in perspective.

The reality is that some premature multiples will develop lasting disabilities, ranging from intellectual disability to cerebral palsy to vision or hearing loss. Some may experience developmental delays, learning problems in school, or attention deficits. Others may require glasses or develop allergies or asthma. Many conditions can be treated or improved with early intervention programs, including physical, speech, or occupational therapies. Other complications may be corrected surgically. And plenty of premature multiples will lead lives with absolutely no consequences from their early start in life.

There is no way to predict individual outcomes. No doctor has a crystal ball to predict whether a premature baby will grow up healthy. But parents can help ensure the best outcomes for their multiples by being aware of the potential complications and partnering with their children's medical caregivers to monitor their development and obtain support when needed.

11 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  8. National Eye Institute. Retinopathy of prematurity.

  9. Doyle LW, Anderson PJ, Battin M, et al. Long term follow up of high risk children: who, why and how?. BMC Pediatr. 2014;14:279. doi:10.1186/1471-2431-14-279

  10. Swamy, GK, Østbye T, Skjærven R. Association of preterm birth with long-term survival, reproduction, and next-generation preterm birthJAMA. 2008;299(12):1429–1436. doi:10.1001/jama.299.12.1429

  11. World Health Organization. Born Too Soon: The Global Action Report on Preterm Birth.

By Pamela Prindle Fierro
 Pamela Prindle Fierro is the author of several parenting books and the mother of twin girls.