Preterm-Born Mothers More Prone to Preterm Babies

A new study adds a new dimension of truth to the saying “like mother, like daughter/son.” The study revealed that mothers who were born prematurely are at increased risk of having at least one child born prematurely, too. The researchers making the discovery hope to use this knowledge to develop a drug that will someday prevent preterm births.

Global Prematurity

Babies born too soon face an immediate need for medical care to save their lives and prevent or minimize any long-term complications. Many require weeks, if not months, in neonatal intensive care units (NICUs) so they can get the best start possible in life. According to the March of Dimes, 15 million babies around the world are born prematurely every year. More babies die each year because of complications of preterm birth than from any other cause.

Prematurity Rate High in US

One in nine babies (approximately 450,000) in the United States are preemies, accounting for 11.4% of all US births each year. The annual US rate of preterm births is one of the highest in the world, higher than in most developed countries.

Dr. Anne Monique Nuyt wants to save babies from the dangers of preterm births. She and her colleagues at the Centre Hospitalier Universitaire Sainte-Justine are developing a drug that will prevent prematurity and give more children a chance at a long, healthy live. The center is the pediatric and obstetric affiliate of the Université de Montréal in Quebec, Canada.

Previous studies have shown that women who were born at low birth-weight are at increased risk of delivering their own babies prematurely but Nuyt and her research team were interested in another group of women, too: those who were born prematurely but at birth-weights appropriate for their gestational age at birth.

The Mothers

To explore the childbirth outcomes of women born prematurely but at weights normal for their gestational age, the researchers analyzed birth records of women born in Quebec between 1976 and 1995. They found:

• 51,148 women had been preemies.
• 823,991 were born at full term.

Of this entire group of female babies, those that had grown up and had children of their own were:

• 7,405 from the preemies group who were born at appropriate weight for gestational age:
  
  • 554 had been born before week 32 (very preterm).
  • 6,851 had been born between weeks 32 and 36 (preterm).
  • These women had given birth to 12,248 children of their own.
  • 16,714 full-term moms had had 27,879 babies.

Their Babies

In the entire study group, mothers giving birth to at least one premature baby included:

• 14.2% of the very preterm women.
• 13.0% of the preterm women.
• 9.8% of the mothers born at full term.

In contrast to women born at full term, the risk that a prematurely born woman would have her first live birth delivered prematurely was increased:

• 1.63-fold (63%) for very preterm women.
• 1.41-fold (41%) for preterm women.

Nuyt said, “Knowing that being born preterm is a risk factor for expectant mothers, obstetricians could inform their patients of the warning signs of premature labour so they can be vigilant and respond quickly if contractions occur.” Since women born earliest, regardless of gestational age birth-weight, are at greatest risk of preterm deliveries, it is important that pregnant women and their healthcare providers consider this factor throughout each pregnancy.

Sources:

1. Nuyt, Anne Monique, et al. "Risk for Preterm and Very Preterm Delivery in Women Who Were Born Preterm." Obstetrics & Gynecology 125.5 (2015): 1177-84. Wolters Kluwer Health, Inc.. Web. 3 June 2015.
2. "Prematurity Campaign." March of Dimes. March of Dimes Foundation, n.d. Web. 3 June 2015.