After 10 months of pregnancy and numerous hurdles to overcome, we finally got to the point of unloading the baby, only to hear that there was another invisible killer waiting for us on the way – GBS screening. What the heck is GBS screening? Group B hemolytic streptococcus, also known as S. agalactiac, is a Gram-positive coccus that may be found in the gastrointestinal, respiratory, urinary and reproductive tracts and is a conditional pathogen. What are the effects of GBS on pregnant women? The rate of GBS carriage among pregnant women is 3.7%-32.4%. It is not generally pathogenic in good health, but the poor immunity of pregnant women will give this invisible killer a chance to take advantage of it. Once the pregnant mother is infected, GBS colonization in the mother can lead to chorioamnionitis, myometrial necrosis, preterm labor, preterm fetal membranes, postpartum endometritis and infectious miscarriage. What are the effects of GBS on the baby? The main route of transmission of GBS is vertical transmission from mother to child and is related to the mode of delivery. After the pregnant mother is infected with GBS, the infected amniotic fluid during delivery can be transmitted vertically to the newborn through the fetal airway or through the birth canal, resulting in sepsis, pneumonia, and meningitis in the baby. Outbreaks of GBS disease are related to the age of the newborn and are classified as early-onset or late-onset: Early-onset Early-onset sepsis is common within 6 days of birth and symptoms usually include respiratory distress, apnea, and signs of sepsis; pneumonia and meningitis are the more common forms of early-onset GBS disease; it is often transmitted through delivery by asymptomatic carrier mothers. Late onset Late onset septic meningitis has an age of onset of 1 week to 3 months, with an average of 4 weeks; respiratory symptoms are uncommon and are often associated with sepsis; the mortality rate is approximately 15%, but survivors can have sequelae such as dementia and hydrocephalus. Mothers-to-be are advised to have a comprehensive prenatal microbiological screening at 35-37 weeks of gestation to ensure the health of the mother-to-be and the fetus.