In the first month of life, babies usually catch up and exceed their birth weight, but then continue to gain weight. A weight loss of up to about 10 per cent of birth weight is normal in the first two to three days after birth. However, the baby should have regained this and reached his birth weight by about two weeks. While all babies can grow at different rates, the following gives the average for boys and girls up to 1 month of age: Weight: After the first two weeks, you should be gaining about 1 ounce each day Average length at birth: 20 inches for boys, 19 ¾ inches for girls Average length at one month: 21 ½ inches for boys, 21 inches for girls Head Size: Increases to a little less than 1 inch more than birth size by the end of the first month What factors determine the physical growth of my newborn? Various things can affect a baby’s size at birth. The duration of the pregnancy is important. Babies born around the term or later tend to be taller than those born earlier. Other factors are: Size of the parents. Tall and tall parents can have larger than average newborns; Small and petite parents may have subpar newborns. Multiple births. With twins, triplets or other multiples, parents can assume that their babies may be a bit small. Multiple babies must share their growing space in the uterus, and they are often born prematurely, resulting in a smaller size at birth. Order of birth. Firstborns are sometimes smaller than later-born brothers or sisters. Gender. Girls tend to be smaller and boys larger, but the differences are small at birth. Mom’s health during pregnancy. Babies may have a lower birth weight if the mother has high blood pressure or heart problems; or has consumed cigarettes, alcohol or illegal drugs during pregnancy. If the mother has diabetes or is overweight, the baby may have a higher birth weight. Nutrition during pregnancy. Good nutrition is crucial for a baby’s growth – before and after birth. Poor nutrition during pregnancy can affect how much a newborn weighs and how the infant grows. Excessive weight gain can increase the likelihood that a baby will be born larger than average. Baby’s health Medical problems, including some birth defects and some infections during pregnancy, can affect a newborn’s birth weight and later growth. What does my baby understand? You may find that your baby responds in many ways, including the following: Frightening loud noises View faces and images with contrasting black-and-white images Pay attention to the voices and finally to the sounds Show hints of a smile, especially while sleeping How long should my newborn sleep? Newborns should sleep 14 to 17 hours out of any 24-hour period, says the National Sleep Foundation. Some newborns sleep up to 18-19 hours a day. Although newborns spend most of the 24 hours sleeping, it’s best that they don’t sleep more than 5 hours at a time for the first 5-6 weeks as they will need to wake up every few hours to eat. Breastfed babies feed often, about every 2-3 hours. Bottle-fed babies tend to drink less frequently, about every 3-4 hours. Expect to wake your newborn to eat every 2-3 hours until he exceeds his birth weight, which is usually within the first few weeks. After that, it’s okay to let your baby sleep in longer at night if he’s gaining appropriate weight (about 1 pound every 2 weeks). The first few months of a baby’s life can be the most difficult for parents, who often get up at night to take care of their baby. Every baby has a different sleep pattern. Some start to “sleep through the night” (for 5-6 hours at a time) at 2-3 months of age, but others don’t.