Infertility issues may account for some adverse birth outcomes with assisted reproduction

Key takeaways :

• Same-sex couples using ART had similar birth outcomes as heterosexual couples conceiving naturally.
• Infertility-related factors may contribute to higher adverse birth outcomes with technology-assisted birth.

Same-sex couples undergoing assisted reproductive technology experienced more favorable or similar birth outcomes vs. heterosexual couples, suggesting infertility-related factors contribute to higher adverse birth outcomes, data show.

“Higher rates of adverse birth outcomes have been consistently reported among children conceived via assisted reproductive technology (ART) compared with children conceived through natural conception. Higher rates of multiple births in ART pregnancies partially explain the increased risk,” Alice Goisis, PhD, associate professor in demography and deputy research director at the Centre for Longitudinal Studies at the University College London, and colleagues wrote.

To assess whether additional differences in adverse outcomes might be due to ART or to infertility issues leading to the use of technology, the researchers compared outcomes among same-sex couples — who were assumed to be less likely be using ART for infertility issues — and heterosexual couples.

This study, published in JAMA, included all births in Sweden from 2007 to 2018. Using the Swedish National Quality Registry for Assisted Reproduction, researchers linked all ART treatments, including IVF, intracytoplasmic sperm injection and intrauterine insemination, to the medical birth register and the total population registers. Researchers evaluated birth weight, gestational age, low birth weight less than 2,500 g and preterm delivery at less than 37 weeks’ gestation.

Overall, there were 868 births using ART among same-sex lesbian couples, 23,488 births using ART among heterosexual couples and 456,898 naturally conceived births. ART-conceived births from both same-sex and heterosexual couples demonstrated a higher proportion of multiplicity compared with naturally conceived births (5.8% and 7.5% vs. 2.1%, respectively), according to the researchers.

Couples who conceived naturally had infants with significantly lower birth weight (3,429.5 g vs. 3,460.2 g) and younger gestational age (277.6 vs. 278.1 days) with similar risks for low birth weight (4.9% vs. 6.7%) and preterm delivery (6.9% vs. 9.1%) as same-sex couples who conceived through ART.

In addition, heterosexual couples who conceived through ART had infants with statistically significantly lower birth weight (3,342.9 g vs. 3,460.2 g) and younger gestational age (274.7 vs. 278.1 days) compared with same-sex couples, the researchers reported.

Low birth weight and preterm birth percentages were higher among ART conceptions among heterosexual couples compared with same-sex couples, but these were not statistically significant.

“This study demonstrated that same-sex lesbian couples undergoing ART had more favorable or similar birth outcomes to heterosexual couples who conceived naturally or underwent ART to conceive, suggesting that infertility-related factors rather than reproductive treatments contribute to higher rates of adverse birth outcomes in ART pregnancies,” the researchers wrote.