While you cannot ever know everything about parenting, as there is always a new load of information. Right now, what is making rounds on TikTok is the 99th percentile baby trend. A Brisbane mom went viral after she shared her experience of giving birth to a baby in the 99th percentile for weight. Britanny Opetaia-Halls birthed her daughter who weighs 22 pounds, 9 ounces, which is about 5 pounds heavier than the average baby her age.Dr Sermed Mezher, a digital health content creator, and a London based GP, shared: "Babies in the womb who measure in the 99th percentile for weight are referred to as macrosomic baby, meaning they are significantly larger than average for their gestational age. While most macrosomic babies are healthy, their larger size can increase the risk of certain complications during pregnancy and delivery."Also Read: C-Section Births May Raise Odds Of Leukemia In Children, Study FindsWhat Does the 99th Percentile Mean for a Baby?Babies in the 99th percentile for weight are larger than 99% of babies at the same gestational age. This may lead to birth complications such as shoulder dystocia—when the baby’s shoulders become stuck during delivery—or increase the likelihood of cesarean section. Mothers may also experience a higher risk of perineal tearing, postpartum hemorrhage, and greater pregnancy weight gain. Contributing factors include maternal diabetes, genetics, or excess weight gain during pregnancy.This larger birth size is medically categorized under fetal macrosomia, which refers to babies in the top 10% of weight for gestational age—with the 99th percentile representing the most extreme cases.What Causes a Baby to Be in the 99th Percentile?There are certain reasons why a baby may fall into the 99th percentile for weight:You have a large fundal height (a measurement of fetal growth)Significant weight gain during pregnancyGestational diabetes or pre-existing diabetesHistory of delivering large babiesProlonged pregnancy past due dateParental genetics (you were a large baby yourself)How Is 99th Percentile Baby Diagnosed?Your healthcare provider may recommend an ultrasound to estimate fetal weight and amniotic fluid volume. Ultrasound imaging can estimate weight within about 10%, but it isn’t precise. For example, if it estimates your baby weighs 9 pounds, the true weight could range between 8 to 10 pounds. While it can’t predict complications like shoulder dystocia, providers will assess all clinical factors to determine the safest delivery plan.99th Percentile Baby: Possible RisksAccording to a 2013 study published in the Maternal and Child Health Journal, babies born in the 99th percentile may face increased health risks later in life. Research shows they are 1.52 times more likely to become overweight or obese by age 7, and another study linked early childhood obesity to high birth weight.Also Read: Aspirin Isn’t Always Safe For Older Adults Anymore—Here's Why Doctors Are Warning Against ItThese babies may also experience complications shortly after birth, including low blood sugar levels and a higher risk of developing metabolic syndrome—a cluster of conditions that raise the risk of heart disease, diabetes, and stroke.