Experts warn trend of giant babies on TikTok linked to rising macrosomia

A social-media trend celebrating oversized newborns has drawn the attention of health experts who say it reflects a real pregnancy issue: foetal macrosomia, or babies born larger than typical. Macrosomia is defined as a newborn weighing 4,000 grams (about 8 pounds 13 ounces) or more and can complicate delivery and long-term health. The trend has surged on TikTok under the banner #BigBaby, with parents posting clips of infants whose measurements far exceed average ranges and viewers reacting with astonishment and praise.

The trend comes amid continuing concerns that more babies are born larger than in previous generations. In the United Kingdom, observers say macrosomia has become more common in recent decades. Dr Dimitrios Siassakos, professor of obstetrics at University College London, said national statistics show babies are getting bigger. “If you use the 90th centile as a cut-off, you’d normally expect 10 percent of babies to have macrosomia. The reality is higher—and we see so many more than 10 percent nowadays,” he said. He and other experts point to two main drivers: rising maternal obesity and increasing rates of diabetes, including gestational diabetes. “Women with untreated gestational diabetes are much more likely to have big babies,” he added, noting that the condition can be present even in women who are not overweight.

Two main subtypes of macrosomia help explain the health risks. Symmetric macrosomia occurs when the baby's tummy circumference is in proportion to its length, resulting in a generally longer baby with a larger frame. This form is less often associated with health problems and tends to appear in babies born to tall parents. Asymmetric macrosomia, by contrast, features a disproportionately large belly and shoulders relative to length, and is more often linked to untreated gestational diabetes. Diabetes UK estimates that gestational diabetes affects about one in 20 pregnancies in the UK, with some estimates reaching one in five; the condition can develop at any point in pregnancy and may not cause noticeable symptoms.

The condition has real consequences at birth and beyond. Large babies are at higher risk for delivery complications, including shoulder dystocia, where the shoulders become stuck during birth, need for operative delivery, and emergency cesarean sections. In rare but serious cases, infants can suffer oxygen deprivation or nerve injuries during birth. Professor Amanda Sferruzzi-Perri, a foetal and placental physiology expert at the University of Cambridge, noted that undiagnosed or poorly managed gestational diabetes can alter fetal glucose handling, stimulating excess insulin production in the fetus and promoting fat deposition and bone growth. “This is a major concern because macrosomia can have risks for the baby,” she said. For mothers, larger babies can lead to longer, more complex deliveries and a higher likelihood of C-sections.

Numerous stories circulating on social media have highlighted examples of very large newborns. Four-month-old Gunner, born to Maci Mugele in Oklahoma, weighed about 22 pounds and measured roughly two and a half feet long, prompting backlash and questions about feeding and care from some commenters. In another widely viewed clip, influencer Houri Hassan-Yari described her child as a “99th-percentile” six-month-old. The baby’s size has attracted both praise and concerns about potential health risks. Not all reports align with the positive framing of the trend; others warn that oversized babies may reflect underlying conditions that require medical attention.

Medical guidance emphasizes that macrosomia is preventable or at least manageable when gestational diabetes or maternal obesity is identified early and treated. The most effective approach to reducing risk is lifestyle modification during pregnancy, including regular physical activity and a balanced diet. “The most effective treatment for gestational diabetes is lifestyle modification—and not anything particularly drastic,” Siassakos said. “Making sure you exercise regularly, and taking a common-sense approach to diet, can reduce the risk that both you and your baby will develop diabetes later in life.”

Gestational diabetes remains a key factor in macrosomia, and experts say screening is essential but imperfect. Current guidelines typically test pregnant people with risk factors, such as obesity, a family history of diabetes, or a prior gestational diabetes diagnosis. Yet many cases go undiagnosed, and some studies suggest standard tests detect fewer than half of cases. When gestational diabetes is identified and managed, the risk of complications drops significantly. Still, experts caution that even women at a healthy weight can develop diabetes during pregnancy, and the condition can have long-term implications for both mother and child. A fourfold increased risk of future diabetes has been observed for women who give birth to macrosomic babies.

In addition to diabetes, other factors influence the odds of a large baby. Older maternal age and higher parity (having more pregnancies) are associated with increased risk, and some data suggest male fetuses may be slightly more likely to grow larger in utero. The condition is not rare: clinics report that a substantial minority of pregnancies involve larger-than-average babies, and the rise in macrosomia has contributed to higher cesarean-section rates. In the UK, cesarean deliveries account for nearly half of births, a trend that health professionals say is partly driven by the difficulties associated with delivering macrosomic babies.

Across history, some of the heaviest babies on record illustrate the extreme end of the spectrum. The heaviest baby ever born in the United Kingdom weighed 15 pounds 8 ounces in 1992, while reports from later decades describe newborns at or above 12 pounds. While such cases are uncommon, they underscore the range of outcomes associated with macrosomia and the importance of careful prenatal care and delivery planning.

The broader health story is clear: when gestational diabetes or obesity goes unrecognised and untreated, the likelihood of a macrosomic infant rises, with potential immediate complications and longer-term health implications. However, the evidence also shows that with timely screening, monitoring, and lifestyle adjustments, many of these risks can be mitigated, improving outcomes for both mothers and babies. Health officials urge continued attention to diabetes screening during pregnancy and to public health strategies aimed at reducing obesity, with the understanding that individual cases vary and that media portrayals should not obscure medical guidance or patient care.