HELLP syndrome poses serious risks to babies, primarily through premature delivery, restricted growth in the womb, and complications that often require intensive care after birth. In one study of HELLP-affected pregnancies, more than half of infants showed signs of growth restriction, and nearly a quarter developed breathing difficulties after delivery. The severity depends largely on how early in pregnancy HELLP develops and how quickly the baby needs to be delivered.
Why HELLP Disrupts the Baby’s Environment
HELLP syndrome damages the tiny blood vessels that supply the placenta. The condition triggers widespread vasospasm (tightening of blood vessels) and abnormal blood clotting in the mother, which reduces blood flow through the placenta. Since the placenta is the baby’s only source of oxygen and nutrients, this restricted blood flow directly limits what the baby receives.
The placenta can also separate from the uterine wall earlier than it should, a complication called placental abruption. When blood flow through the placenta drops significantly, the baby may show signs of distress, including changes in heart rate that signal oxygen deprivation. In the Turkish-German Gynecological Association study of 64 HELLP pregnancies, fetal distress was documented in 45% of cases.
Growth Restriction in the Womb
Because the placenta can’t deliver adequate nutrition, many babies with HELLP-affected mothers are smaller than expected for their gestational age. In one study, nearly 55% of babies born to mothers with HELLP syndrome had intrauterine growth restriction. Low amniotic fluid, another sign that the baby isn’t getting enough blood flow, occurred in about 47% of cases. These two complications often appear together and are among the first signs that HELLP is affecting the baby before delivery.
The Impact of Early Delivery
The only definitive treatment for HELLP syndrome is delivering the baby, which frequently means a premature birth. Many HELLP cases develop before 34 weeks of gestation, and doctors often cannot safely delay delivery to allow the baby more time to mature. Clinical guidelines specifically note that indicated preterm deliveries for conditions like severe preeclampsia and HELLP should not be postponed.
Prematurity is the single biggest driver of complications for the baby. Organs that aren’t fully developed, especially the lungs, create immediate challenges outside the womb. Respiratory distress syndrome affected about 23% of infants in the HELLP cohort studied, and it’s one of the most common reasons these babies need intensive care. When time permits, doctors give the mother steroid injections before delivery to help speed up the baby’s lung development, but this window isn’t always available in emergencies.
What Happens After Birth
Most babies born from HELLP pregnancies require time in the neonatal intensive care unit. The leading reasons for admission include prematurity, breathing problems, and oxygen deprivation that may have occurred before or during delivery.
Several specific complications are more common in these newborns:
- Low platelet count: Between 15% and 38% of babies born to mothers with HELLP develop their own drop in platelets, the blood cells responsible for clotting. This can increase the risk of bleeding.
- Bleeding in the brain: Known as intraventricular hemorrhage, this is more likely in HELLP-affected infants, particularly those born very early. It ranges from mild (often resolving on its own) to severe (potentially causing lasting damage).
- Low Apgar scores: More than half of infants in one study scored below 7 on the one-minute Apgar assessment, which measures a newborn’s heart rate, breathing, muscle tone, reflexes, and color. By five minutes, 37.5% still scored below 7, indicating ongoing need for medical support.
- Infection: About 8% of newborns in the studied cohort developed sepsis, a serious bloodstream infection that premature babies are especially vulnerable to.
- Seizures: Roughly 11% of affected newborns experienced convulsions, which can result from oxygen deprivation or bleeding in the brain.
Perinatal Survival Rates
HELLP syndrome carries real mortality risk for the baby. In one study covering cases from 2000 to 2006, the fetal mortality rate was about 19%, and the neonatal mortality rate (deaths occurring after birth) was about 20%. These numbers reflect the full spectrum of HELLP severity, including very early-onset cases where the baby is delivered well before viability. Babies born closer to term, or those whose mothers developed HELLP later in pregnancy, generally fare significantly better.
Prematurity, growth restriction, oxygen deprivation, placental problems, and abruption are the leading causes of these losses. The earlier HELLP develops, the higher the risk, because the baby has less time to grow and the placenta is compromised for a longer period.
Long-Term Development
For babies who survive, the question of lasting effects is understandably important to parents. A follow-up study tracked 178 children born after severe early-onset hypertensive complications of pregnancy (including HELLP) and assessed them at age 4.5. The average gestational age at birth was about 31 weeks, and 90% had been growth-restricted.
At the 4.5-year assessment, 20% of the children had abnormal developmental outcomes, which included below-average scores on intelligence testing, motor skill delays, or neurological problems. When researchers combined all measures into a composite score, 37% showed at least one area of concern. The risk was highest among children born at the lowest gestational ages and birth weights. Children born later in the preterm period had better outcomes overall.
These numbers reflect early-onset, severe cases. Babies born from HELLP that develops closer to term, say after 34 weeks, typically have much better developmental trajectories because they face fewer consequences of prematurity and spend less time with compromised placental function.