Why Does Marginal Cord Insertion Happen?
Marginal cord insertion normally results from the abnormal placement of early placental cells during implantation. Researchers have not identified an exact reason why this occurs, but some risk factors increase the likelihood of it occurring, including:
- Pregnancy with multiples, such as twins and triplets
- Maternal age over 35
- Use of artificial reproductive technology, such as in vitro fertilization
- Use of an intrauterine device as contraception before pregnancy
- Maternal chronic diseases, such as diabetes and hypertension
- Drug abuse while pregnant
- First-time pregnancy
According to one study based on 634,741 pregnancies, the prevalence of abnormal cord insertion was 7.8 percent (1.5 percent velamentous, 6.3 percent marginal) in single-baby pregnancies and 16.9 percent in twin pregnancies.
Diagnosing Marginal Cord Insertion
Most cases of marginal cord insertion are asymptomatic. Pregnant women with the condition often do not suspect a problem until they undergo a routine prenatal ultrasound. Marginal cord insertion diagnosis most commonly occurs during the second trimester (weeks 14–27 of pregnancy).
Healthcare providers may use an ultrasound to evaluate blood flow through the umbilical cord and placenta. The ultrasound Doppler feature allows them to see what part of the placenta the umbilical cord attaches to. An umbilical cord located within two centimeters of the edge of the placenta typically indicates a marginal cord insertion.
Sometimes, marginal cord insertion remains undiagnosed unless related complications arise later in pregnancy. Even then, an ultrasound is not always accurate in determining the location of the cord insertion. Some cases may go undetected until the baby is delivered.
Potential Marginal Cord Insertion Complications
Marginal cord insertion increases the risk of adverse birth outcomes. It primarily affects the baby rather than the mother, but maternal complications are also possible. Complications may include:
- Fetal growth problems – Marginal cord insertion can cause abnormal fetal development. During pregnancy, doctors may refer to this as intrauterine growth restriction. At birth, the baby may be considered small for its gestational age, which normally involves a birth weight beneath 5 pounds, 8 ounces.
- Fetal distress – In some cases, marginal cord insertion can cause issues with blood and oxygen flow to the fetus. This can lead to fetal distress, resulting in reduced movement or heart rates. In cases involving fetal distress late in pregnancy, marginal cord insertion can require a C-section to prevent further complications.
- Preterm birth – Pregnant women experiencing marginal cord insertion are at a higher risk of preterm labor and delivery. Preterm birth is defined as birth before 37 weeks of pregnancy.
- Low Apgar score – This measures a newborn’s overall health at one and five minutes after birth. It evaluates heart rate, breathing, muscle tone, reflex response, and skin tone. Marginal cord insertion can affect any of these factors at birth, resulting in a low Apgar score. It may also increase a newborn’s likelihood of admission into a neonatal intensive care unit.
- Miscarriage or stillbirth – Though uncommon, marginal cord insertion can sometimes contribute to the loss of a pregnancy before 20 weeks (miscarriage) or after 20 weeks (stillbirth).
- Preeclampsia – Pregnant women with marginal cord insertion have an increased risk of developing preeclampsia, a pregnancy complication involving high blood pressure, protein in the urine, and swelling.
- Placental abruption – This condition occurs when the placenta separates from the uterine wall before delivery. Marginal cord insertion increases the risk of a placental abruption, which can be life-threatening for both mother and baby.
Treatment Options
There is no treatment to correct a marginal cord insertion. Instead, the goal after diagnosis is to reduce the risk of adverse outcomes. This may involve more frequent prenatal monitoring and testing to ensure the fetus receives enough oxygen and nutrients.
For example, doctors may order extra ultrasound scans to monitor fetal growth and development. They may also order biophysical profiles and non-stress tests to monitor the fetus’s heart rate and movement.
This monitoring can alert doctors to any concerning changes early on, allowing for prompt intervention. If there are signs of fetal distress or growth restriction, doctors may recommend early delivery through labor induction or emergency C-section.
Labor and delivery teams must also closely monitor the pregnant mother’s health after a marginal cord insertion diagnosis.
Marginal Cord Insertion vs. Velamentous Cord Insertion
Marginal cord insertion can turn into velamentous cord insertion in rare cases. This most commonly occurs during the third trimester (weeks 28–40). Velamentous cord insertion is less common and more concerning than marginal cord insertion. It carries many of the same risks as marginal cord insertion, but they are typically enhanced. Doctors usually recommend more intensive monitoring and earlier delivery due to the higher risks associated with velamentous cord insertion.
With velamentous cord insertion, the umbilical cord does not attach directly to the placenta at all. Instead, it attaches to other membranes within the uterus. As a result, umbilical vessels diverge from the umbilical cord and run along the uterine membranes before reaching the placenta.
Without the umbilical cord’s protection, the vessels are more vulnerable to compression, particularly when the uterus contracts during labor. This can obstruct blood flow to the fetus. As a result, the fetus may receive inadequate oxygen and nutrients, leading to complications such as intrauterine growth restriction, fetal distress, or stillbirth.
Vasa previa is another possible complication unique to velamentous cord insertion. With vasa previa, the unprotected vessels cross the cervix, which lies between the fetus and the birth canal. As the baby descends during labor, the vessels may rupture and cause life-threatening blood loss for both the mother and baby.
Is Marginal Cord Insertion Considered High Risk?
Doctors often consider marginal cord insertion a high-risk condition due to the potential for complications during pregnancy and delivery. However, with careful monitoring and management, marginal cord insertion risks can be reduced. Most women with marginal cord insertion have successful pregnancies and healthy babies.
Generally, the most significant marginal cord insertion risk is intrauterine growth restriction. While a smaller fetus is not necessarily a cause for concern, slowed fetal growth can increase the risk of other complications before and after delivery.
Explore Your Rights and Options With an Experienced Birth Injury Attorney
The standard of care when handling marginal cord insertions is well-established. When healthcare providers fail to uphold that standard, both the mother and child can suffer serious harm. If your healthcare provider failed to diagnose, monitor, or treat a marginal cord insertion appropriately, you may be eligible to seek compensation through a medical malpractice lawsuit.
Our award-winning attorneys are committed to serving our community by providing high-quality legal representation to injury victims throughout Missouri. Do not wait to take legal action. Call (800) 536-4357 or reach out online to schedule your free, no-obligation consultation.
Sources
- Ebbing, Catherine, et al. “Prevalence, Risk Factors and Outcomes of Velamentous and Marginal Cord Insertions: A Population-Based Study of 634,741 Pregnancies.” National Library of Medicine, 30 Jul. 2013.
- Cotter, Amanda, et al. “Abnormal Placental Cord Insertion and Adverse Pregnancy Outcomes: A Systematic Review and Meta-Analysis.” National Library of Medicine, 6 Dec. 2017.
- Nkwabong, Elie, et al. “Outcome of Pregnancies with Marginal Umbilical Cord Insertion.” National Library of Medicine, 17 June 2019.
- Rocha, Juliana, et al. “Velamentous Cord Insertion in a Singleton Pregnancy: An Obscure Cause of Emergency Cesarean—A Case Report.” National Library of Medicine, 29 Nov. 2012.
- Siargkas, Antonios, et al. “Impact of Velamentous Cord Insertion on Perinatal Outcomes: A Systematic Review and Meta-Analysis.” National Library of Medicine, 12 Nov. 2022.
