Globally, one in six babies are born with a low birthweight and one in 10 are born preterm. The Global Nutrition Target for 30% reduction in low birthweight by 2025 is off track and preterm rates are rising in many countries.

Newborns with low birthweight include those born preterm or small for gestational age, and those with both conditions. Such infants are at risk of early mortality and poor health throughout their life course. However, birthweight and gestational age are often measured separately, meaning the two types of low birthweight cannot be distinguished; small for gestational age infants may not be recognized due to lack of knowledge of gestational age; and stillbirths are omitted. New approaches are needed.

The Vulnerable Newborn Measurement Collaboration has more than 250 members, including governments, implementers, and researchers. The collaborative has enabled a massive dataset of 279.3 million live births from 23 high-income and 14 low- and middle-income countries from 2000 to 2021. This dataset allows newborn types to be determined by combining gestational age (preterm vs. term) and size (small, appropriate, and large for gestational age), enabling more targeted care and elucidating aetiology to accelerate health of vulnerable newborns globally.

We share novel findings, and then a panel of country representatives and experts will map the way forward. This panel links to the Lancet Small Vulnerable Newborn series, "Born Too Soon Decade" report, and Vulnerable Newborn supplement in BJOG, which will be launched at the International Maternal Newborn Health Conference (IMNHC). We aim to inform actions before IMNHC 2025.