Babies with CS are usually large at birth, and facially unremarkable. Polyhydramnios (excessive amniotic fluid) is common. Nearly all children with CS have severe feeding difficulties, and reflux (vomiting after feeding). Some babies require tube or gastrostomy feeding. Infants may be irritable and hypersensitive to sound and touch. These features usually improve after age two.
Rarely, cardiomyopathy may be very severe in the newborn period. In this small group of very ill babies, hypoglycaemia (low blood sugar) and breathing difficulties are common.
Over time, facial features can include macrocephaly (large head), low-set ears with large, thick lobes and thick lips. Excessive loose skin develops on the palms, fingers and soles, which may thicken over time. Papillomata (small wart-like growths) may occur around the mouth and nostrils.
Joint differences are common, including an unusual posture of the wrists. Scoliosis (curvature of the spine) is also common. People with CS are usually short.
Developmental milestones are delayed. Most children will learn to walk and talk, but the age of doing these is usually delayed, and not all children will acquire age-appropriate skills. Although developmental delay is nearly always present, it is variable. Many children attend mainstream school in the infant and primary years.
Some individuals with CS have developed cancer; this cancer risk appears to be greatest in the first years of life, particularly for a tumour of muscle called embryonal rhabdomysosarcoma. Although this can start in any skeletal muscle, it is commonest in the abdomen and pelvis. An increased risk of bladder cancer occurs from adolescence.