Diabetes that develops during pregnancy can be associated with increased fetal growth. Monitoring and managing the condition may be an important part of prenatal care.
Understanding Fetal Macrosomia
Fetal macrosomia describes a baby with a higher-than-expected birth weight. This page can help your family understand how a larger baby may affect pregnancy and delivery, what complications doctors may evaluate, and when it may be appropriate to ask whether the care met accepted medical standards.
What is fetal macrosomia?
Fetal macrosomia is the medical term used when a newborn has an unusually high birth weight. There is a wide range of healthy birth weights, and being larger than average does not necessarily mean that a baby or mother will experience an injury.
A baby’s exact weight cannot be known until birth. During pregnancy, however, doctors can use ultrasound and other clinical information to estimate fetal size and determine whether the baby may be larger than expected for the stage of pregnancy. Those estimates can help guide monitoring and delivery planning, but they are not exact.
How fetal macrosomia may be identified
Fetal macrosomia is confirmed after delivery based on the baby’s birth weight. Before birth, the medical team may identify reasons to monitor the baby’s growth more closely, including:
- Ultrasound estimates suggesting that the baby may be larger than expected for the stage of pregnancy
- Gestational diabetes or diabetes that was present before pregnancy
- Greater-than-expected weight gain during pregnancy
- A pattern of fetal growth that leads the medical team to reassess the delivery plan
Because prenatal weight estimates have limitations, a suspected large baby does not automatically require one particular delivery method. The medical team should consider the full clinical picture and discuss an individualized plan with the family.
What causes or increases the likelihood of fetal macrosomia?
A baby may have fetal macrosomia for more than one reason, and not every case has a single identifiable cause. Possible factors include:
- Gestational diabetes that develops during pregnancy
- Diabetes mellitus that was present before pregnancy
- Greater-than-expected weight gain during pregnancy
- Parental body size and other family-related influences on birth weight
The presence of one of these factors does not mean that complications will occur or that anyone did something wrong. It may, however, support closer attention to fetal growth and thoughtful planning for labor and delivery.
When fetal macrosomia may be medical malpractice
Not every case of fetal macrosomia, difficult delivery, or related birth injury is caused by medical malpractice. A baby can be larger than average even when prenatal and delivery care are appropriate, and estimates of fetal weight are not exact. However, the following circumstances may point to negligence if they fell below accepted medical standards and contributed to an injury:
- Failing to identify, monitor, or appropriately manage gestational diabetes or another known risk factor
- Failing to monitor fetal growth when the pregnancy presented reasons for closer assessment
- Failing to order, perform, interpret, or follow up on an ultrasound when it was clinically appropriate
- Failing to consider the baby’s estimated size and the mother’s clinical history when planning the delivery
- Failing to discuss or consider cesarean delivery when it was a medically appropriate option under the circumstances
- Failing to respond appropriately to prolonged or obstructed labor, shoulder dystocia, or signs that the baby was not tolerating labor
- Using excessive force during delivery and causing or worsening a nerve injury or other birth trauma
- Failing to evaluate and treat the newborn after a difficult delivery involving possible oxygen deprivation or nerve damage
Wais, Vogelstein, Forman, Koch & Norman, LLC works with medical experts to review prenatal records, imaging, labor and delivery documentation, and newborn evaluations and assess whether the care met accepted medical standards.
Treatment and long-term outlook
Fetal macrosomia is not itself an injury that is treated after birth. During pregnancy, care generally focuses on monitoring fetal growth, managing conditions such as diabetes, and developing a delivery plan based on the mother and baby’s individual circumstances. Depending on the full clinical picture, that plan may involve preparing for a vaginal delivery or considering cesarean delivery when the medical team believes it is the safer option.
After birth, care depends on whether the baby or mother experienced a complication. A newborn may need evaluation and treatment for an injury related to a difficult delivery, shoulder dystocia, oxygen deprivation, or nerve damage.
Many babies with fetal macrosomia do not have lasting health effects. When an injury does occur, the long-term outlook depends on the type and severity of that injury, how quickly it was recognized, and the treatment and follow-up the child receives.
Risk Factors: Fetal Macrosomia
Recognizing factors associated with fetal macrosomia.
Understanding the factors associated with fetal macrosomia can help families see why closer growth monitoring or additional delivery planning may have been recommended. A risk factor does not mean that a larger baby or birth complication is inevitable.
Gestational diabetes
Pregnancy weight gain
Greater-than-expected weight gain during pregnancy is another factor associated with fetal macrosomia. It should be considered together with the rest of the pregnancy history.
Preexisting diabetes
Diabetes that was present before pregnancy may also increase the likelihood of a larger baby. The care plan may include closer attention to both maternal health and fetal growth.
Family and body size
Parental body size and family-related influences can affect a baby’s birth weight. This factor alone does not indicate that a complication was preventable or that care was improper.
Frequently Asked Questions
Common questions about fetal macrosomia.
Clear information can help your family better understand the pregnancy, the delivery, and the questions you may want to raise with medical and legal professionals.
How are fetal macrosomia and shoulder dystocia related?
A larger baby may be more difficult to deliver and can increase concern about shoulder dystocia, which occurs when a baby’s shoulder becomes lodged during birth. However, fetal macrosomia does not always lead to shoulder dystocia, and shoulder dystocia can occur even when a baby is not unusually large.
Is fetal macrosomia always caused by medical malpractice?
No. A baby can have fetal macrosomia even when prenatal care is appropriate, and the baby’s exact weight cannot be known until birth. Medical malpractice may be a concern when providers failed to monitor or manage known risk factors, did not appropriately assess fetal growth, or failed to develop and carry out a reasonable delivery plan, and that failure contributed to an injury.
How is fetal macrosomia managed before and after birth?
Before birth, management may include estimating fetal growth, addressing conditions such as diabetes, and planning the delivery based on the full clinical picture. After birth, fetal macrosomia itself does not require treatment, but the baby should be evaluated and treated for any complications or injuries associated with a difficult delivery.
How long do families have to file a fetal macrosomia injury claim?
The deadline, or the statute of limitations, varies by state and may depend on the child’s age, when the injury was discovered, the type of healthcare provider involved, and whether special notice or government-claim rules apply. Some deadlines are shorter than families expect, so prompt legal review can help clarify the time limit and preserve relevant records.
