Fetal distress is an umbrella term used to describe warning signs that indicate a fetus may be experiencing health problems. Fetal distress can occur quickly, with little warning. If the mother and her fetus are not properly monitored, complications can be overlooked. Fetal distress most commonly occurs shortly before or during birth. In many cases, fetal distress can be treated by emergency delivery using forceps, a vacuum extractor, or a Caesarean section (C-section).
Causes of Fetal Distress
There are several complications that can lead to fetal distress, including:
- Abnormal positioning or presentation of the fetus during delivery
- Multiple births, or the delivery of more than one fetus in a single term (twins, triplets, etc.)
- Umbilical cord prolapse, when the umbilical cord precedes the baby during delivery
- Shoulder dystocia, or the catching of a newborn’s shoulder on the mother’s hip during delivery
- Nuchal cord, or the wrapping of the umbilical cord around the neck of the fetus
- Complete or incomplete uterine rupture, or the tearing of the uterus during delivery
Signs of Fetal Distress
Warning signs that can suggest fetal distress include:
- Decreased or irregular fetal movement inside the womb
- Decreased or increased fetal heart rate, particularly surrounding a contraction
- Presence of meconium, or an infant’s first stool, in the amniotic fluid
- Increased levels of lactate in the fetus’ blood that indicates lactic acidosis
Diagnosing Fetal Distress
The most common ways to determine fetal distress before or during childbirth is through fetal heart monitoring (FHM) and close observation of uterine contractions. A steady heart rate is a strong indicator of proper blood flow and overall health. During labor, it is often recommended to check and record the fetal heart rate every 30 minutes. This consistent monitoring can help identify changes in fetal heart rate that may imply fetal distress. Monitoring can be performed in a variety of birth settings, using a variety of tools.
Fetal distress monitoring methods involve:
External Fetal Monitoring
This type of monitoring records the fetal heart rate from outside the mother’s abdomen. The most basic external fetal monitor is a fetoscope, or a specialized stethoscope.Electric hand-held Doppler devices are also used to provide ultrasounds that may help prevent fetal distress.
Internal Fetal Monitoring
Internal monitoring helps identify fetal distress by using a wire electrodethat is typically attached to the head of the fetus through the opening of the mother’s cervix. Contraction strength can be measured by the insertion of a catheter-shaped device into the uterus.
Uterine Contraction Monitoring
A tocodynamometer is a pressure-sensitive device that measures the frequency, length, and strength of contractions. It also measures fetal heart rate for comparison of the direct effects of contractions on fetal heart rate, which can often illustrate fetal distress.
The American Pregnancy Association recommends performing the Fetal Non-Stress Test (NST) after 28 weeks gestation. This external monitoring method uses two belts to detect fetal heart rate and contractions in relation to the movement of the fetus. The NST indicates adequate blood flow and oxygen supply to the fetus, which is essential for preventing fetal distress.
Failure to Treat Fetal Distress
It is critical that an expecting mother and her fetus are properly monitored before and during birth. Untreated fetal distress can have devastating results. Fetal distress may causehypoxia, or a lack of oxygen, that can result in brain damage or infant death.
Long-term effects of fetal distress may include:
- Cerebral palsy
- Mental retardation
- Developmental delays
- Cortical blindness