Postdates

Postdates refers to a pregnancy that extends beyond the expected due date. The due date, also known as the estimated date of delivery (EDD), is typically calculated as 40 weeks from the first day of the woman's last menstrual period. A pregnancy is generally considered postdates or post-term when it reaches 42 weeks (294 days) of gestation. Some sources may also refer to pregnancies between 40 and 42 weeks as "late term."

The exact causes of postdates pregnancy are not fully understood, but some factors may increase the risk. These can include a previous postdates pregnancy, being a first-time mother, obesity, or having a family history of prolonged pregnancies. Certain genetic factors in the baby or issues with the placenta's function might also play a role.

While many postdates pregnancies result in healthy babies, prolonged gestation can carry increased risks for both the mother and the baby. These risks can include a larger baby (macrosomia), which may lead to complications during delivery, such as shoulder dystocia. For the baby, there is also a potential for reduced amniotic fluid (oligohydramnios) and an increased risk of meconium aspiration, where the baby inhales meconium (the first stool) before birth. For the mother, there can be an increased likelihood of interventions like induction of labor or cesarean section, and a higher risk of postpartum hemorrhage.

Management of postdates pregnancies typically involves increased monitoring of the baby's well-being. This often includes non-stress tests, biophysical profiles, and ultrasounds to assess amniotic fluid levels and fetal growth. Once a pregnancy reaches 41 or 42 weeks, healthcare providers may recommend induction of labor to mitigate potential risks. The decision to induce is based on a careful evaluation of the risks and benefits for both mother and baby.