Postterm Pregnancy

Postterm Pregnancy and Birth Injury

Postterm pregnancy (also known as postdate pregnancy, prolonged pregnancy, and postmaturity) refers to a pregnancy that extends beyond the standard gestation time (37-42 weeks).

In cases of postterm pregnancy, the baby may become over-developed in the womb and may be too large, making delivery difficult and increasing the risk for birth trauma, brain bleeds, hypoxic-ischemic encephalopathy (HIE), cerebral palsy, seizures, and other forms of brain damage (1).

Postterm pregnancies also pose a health risk to the baby because placental function and size begin to deteriorate as a pregnancy reaches it’s due date. The more postterm a pregnancy is, the more the placenta deteriorates, placing the baby at risk of fetal oxygen deprivation or nutrient exchange losses. Because of these serious health risks, there is a consensus that it is best to induce labor between 40-41 weeks or sooner rather than letting it continue further (1).

postterm pregnancy

Risk factors for postterm pregnancy

Although there is no way to conclusively determine whether a woman’s pregnancy will extend beyond the normal gestation period, there are certain risk factors that make it more likely. These factors include (1, 2):

  • A prior postterm pregnancy
  • A first pregnancy for the mother
  • A male fetus
  • Genetic factors
  • Obesity
  • Older maternal age
  • The baby’s mother or father was born postterm
  • Mother of caucasian, non-hispanic ethnicity

It is essential that medical professionals recognize these risk factors and consider the possibility of postterm pregnancy during prenatal care.

Fetal and neonatal complications of postterm pregnancy

As a pregnancy continues past 40 weeks, the risk of harm to the baby increases. Many of the complications associated with postterm pregnancy are due to placental insufficiency. As a pregnancy nears term the placenta begins to deteriorate. Because the placenta is the baby’s source of oxygen-rich blood, this deterioration poses a serious risk to the growing fetus (1, 2). Because the baby continues to grow as the pregnancy passes 40 weeks, many other complications of postterm pregnancy are due to large fetal size (1, 2).

The following are common fetal/neonatal complications of postterm pregnancy (1, 2):

If these complications are mismanaged or go untreated, they can lead to severe consequences and/or lifelong disabilities for the baby. The following are common injuries and complications that come as a result of mismanaged postterm pregnancy (1, 2):

  • Stillbirth or neonatal death
  • Postmaturity/dysmaturity syndrome: A condition that results from chronic intrauterine malnutrition due to insufficient placental conditions. Babies born with postmaturity syndrome often have long thin bodies, long nails, have dry skin, and are small for gestational age.
  • Hypoglycemia
  • Cerebral palsy
  • Hypoxic-ischemic encephalopathy (HIE)
  • Seizures

Maternal complications of postterm pregnancy

In addition to the many risks to the baby associated with postterm pregnancy, mothers also face a series of potential complications. The following are common maternal complications associated with postterm pregnancy (1, 2):

  • Postpartum hemorrhage (excessive bleeding following the birth of a baby)
  • Cervical rupture (torn cervix due to the large size of the baby)
  • Infection
  • Perineal injury (injury to the labia, vagina, and/or rectum)
  • Labor dystocia
  • Endometritis (inflammation of the endometrial lining of the uterus)

Preventing postterm pregnancy

Because of the serious risk to both the mother and baby associated with postterm pregnancy, it is essential that medical professionals do everything they can to prevent this condition. There are two major strategies used to prevent postterm pregnancy:

Increased prenatal testing near due date

If a mother has still not delivered by about the 39th or 40th week of pregnancy, the obstetrician will likely order weekly or twice-weekly tests to check on the well-being of the baby (1, 2). Typically these include special fetal monitoring tests like a non-stress test (a test that measures the baby’s movement, heart rate, and reactivity of heart rate to movement, and can indicate if the baby is not receiving enough oxygen due to placental or umbilical cord problems) and biophysical profile (measures the baby’s heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid present). Additionally, ultrasounds should be performed to evaluate the amount of amniotic fluid around the baby (1, 2).

Labor induction by 40-41 weeks gestation

Reports and medical literature state that for even uncomplicated, single baby pregnancies it is best to induce labor by about the 40th or 41st week (1, 2). Similarly, most obstetricians recommend delivery by 41 weeks. Medical professionals must weigh the risks and benefits of labor induction and ensure that the mother and baby are optimal candidates for induction. The benefits of labor induction include reduced C-section rates, lower rates of meconium-stained fluid, less fetal heart abnormalities, reduced oxygen deprivation problems, and much more (1, 2). Unless the mother and baby will be put at serious risk by pursuing labor induction, there is virtually no benefit to prolonging pregnancy beyond 40 weeks and, in fact, strong scientific evidence has shown that any pregnancy beyond 40 weeks of gestation puts the baby and mother at increased risk for health problems (1, 2).

Legal help for postterm pregnancy injuries

If you or a loved one were injured as the result of a mishandled postterm pregnancy, call the award-winning birth injury attorneys at ABC Law Centers: Birth Injury Lawyers. Our legal team has the education, qualifications, results, and accomplishments necessary to succeed. We’ve handled cases involving dozens of different complications, injuries, and instances of medical malpractice related to obstetrics and neonatal care. Our team is able to handle cases from all over the country.

We do not charge for any legal services unless we win your case! To begin your free birth injury case evaluation, contact us in any of the following ways. We’re available to speak with you 24/7.

  • Free Case Review
  • Available 24/7
  • No Fee Unless We Win

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Helpful resources

  1. Norwitz, E. R. (2019, February). Postterm pregnancy. Retrieved from
  2. Norwitz, E. R. (2019, February). Patient education: Postterm pregnancy (Beyond the Basics). Retrieved from