This feature was produced by America’s Health Rankings, and does not reflect the opinions or point of view of Vox Media or Vox Creative. Vox Media editorial staff was not involved in the creation or production of this content.

By Anita Manning

Thanks to research and new technologies, the tiniest of newborns now has a better shot at life than ever before.

While experts say there is still work to be done, the outcome for premature infants has improved dramatically over the last 100 years. In 1915, a baby born prematurely had very little chance for survival, and doctors had few options to save them. Incubators, which were displayed at fairs as sideshow attractions, were unreliable, over heated or under heated, and many physicians dismissed them. Traditional care for preemies was to keep them warm, using warm bricks in cradles or rooms heated to 90 degrees or more, offer nutrition, and try to prevent infection.

As medical technology advanced and neonatal intensive care units were established, smaller and more premature babies were saved. Before the 1970s, most babies born more than three months early did not survive; by the mid-1980s, babies born as early as 24 weeks' gestation could live.

And that brought new problems. From 1993 to 2012, survival rates for babies born between 22 and 28 weeks, considered "extreme preemies,'' increased from 70 percent to 79 percent, but about 90 percent of them have significant health problems — and statistic that hasn't changed since 1993.

First, keeping preterm babies alive; now, keeping them developmentally healthy

Before there were advances in neonatal medicine, "you didn't talk about 27-week gestation babies, because they didn't live,'' says Dr. Michal Elovitz, a high-risk pregnancy specialist and director of Penn Medicine's Prematurity Prevention Program and its Maternal and Child Health Research Program. Now, she says, "the push is not just to stop prematurity, but also to stop the neurobehavioral abnormalities associated with being a preterm infant.''

The earlier a baby is born before 40 weeks gestation, the higher the risk of problems, including cerebral palsy, blindness, deafness, chronic lung disease, abnormal neurological behavior issues and a below-average IQ, Dr. Elovitz says. "A 28-week baby has a 90 percent rate of survival, but a 20 percent to 40 percent rate of abnormal behavior problems,'' she says.

"We're also beginning to find out these kids have different executive abnormalities when they get to school age," Dr. Elovitz says. "There may also be higher rates of ADHD and autism spectrum disorders.'' Even babies born at 34 to 36 weeks gestation, which is considered a late preterm birth, face higher risks of long-term neurologic and developmental problems than those born at term, she says. That's one reason the American Congress of Obstetrics and Gynecology and other groups advocate eliminating elective birth before 39 weeks.

The causes of spontaneous premature birth aren't fully understood, she says, though some factors are known to increase the risk, such as smoking, using cocaine, pregnancy with multiples, or a previous premature birth. "But those risk factors do not identify the majority of women who ultimately have a preterm birth,'' Elovitz says.

"The biggest limitation in the last two decades is we don't fully understand why a preterm birth happens.'' That is a major focus of research at Penn Medicine, one of a network of five March of Dimes Prematurity Research Centers. "That is the challenge,'' Dr. Elovitz says, "to unravel the mechanisms involved in preterm birth, so we can develop effective strategies to prevent it.''

There's a lot of new research underway

In fact, there's a great deal of research underway to decipher the mysteries of preterm labor and come up with ways to prevent it. The research is on both the basic level, looking at the mechanisms of labor, and the clinical level, trying to prevent or improve the outcome of preterm birth, says Dr. Catherine Y. Spong, an obstetrician/gynecologist and acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

- The Genomic and Proteomic Network for Preterm Birth Research, for example, is looking at genes and protein interactions to better understand what happens in preterm birth. One part of this is a study in which DNA samples from about 1,000 women who previously gave birth preterm are compared to samples from women who carried babies to term, to see which genes show up more often in preterm births. This work also involves a longitudinal study of 518 women who previously had preterm births to analyze stored samples taken from them at various points during their pregnancies, to see if there are patterns of protein interactions.

- The placenta is an important organ that is "incredibly understudied,'' says Spong. But when it malfunctions, it can cause problems for mother and baby, leading to gestational diabetes, preeclampsia, stillbirth and preterm birth. The Human Placenta Project aims to develop tools that will allow researchers to track the functioning of the placenta as it develops, to provide information that can be used to prevent serious health problems before they occur.

- A program at Spong's institute, the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be, will enroll 10,000 racially, ethnically, and geographically diverse pregnant women who are having their first babies, looking for commonalities underlining problems such as preterm birth, preeclampsia, and fetal growth restriction and stillbirth. Scientists will study the interactions of genes and the environment, aspects of placental development and function, and how growth and development of genes affect pregnancy outcomes.

- "Omic" technologies refers to new fields like genomics, transcriptomics, proteomics, metabolomics, and interactomics. A Multi-omic Analysis of the Vaginal Microbiome During Pregnancy is a research project that uses these new technologies to understand how the bacterial and microbial species within the female urogenital tract might contribute to preterm birth.

Until more answers are found to questions surrounding premature birth, Spong says, women should do all they can to be as healthy as possible going into a pregnancy. "Optimize any medical conditions you have going in," she says. "Stop smoking, exercise, get your weight into a healthy range. If you have diabetes and it's out of control, that increases the baby's risk." In addition, she recommends taking a prenatal vitamin containing folic acid, or ensuring there is adequate folic acid in the diet to help prevent neural tube defects in the baby.

"If we can optimize pregnancy outcomes,'' Spong says, "we can optimize the health of the nation and the world.''

Read part one of this series of conversations with leading prematurity experts here, as part of America's Health Rankings® Public Health Legacy campaign.

This feature was produced by America’s Health Rankings, and does not reflect the opinions or point of view of Vox Media or Vox Creative. Vox Media editorial staff was not involved in the creation or production of this content.