The size of the uterus at various points in early pregnancy, the date the fetal heartbeat was first heard, and when a mother first feels fetal movement all help confirm pregnancy dates.
Ultrasound (a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs) is often used in early pregnancy to establish or confirm a due date.
Hypoglycemia (low blood sugar) can also occur because the baby has too little glucose-producing stores.
Correct pregnancy dating is important in accurately diagnosing and managing post-term pregnancy.
In amnioinfusion, a sterile fluid is instilled with a catheter (hollow tube) into the broken amniotic sac to help replace the low levels of fluid and cushion the fetus and cord.
Tests often include ultrasound, nonstress testing (how the fetal heart rate responds to fetal activity), and estimation of the amniotic fluid volume.
During labor, the fetal heart rate may be monitored with an electronic monitor to help identify changes in the heart rate due to low oxygenation.
Changes in a baby's condition may require a cesarean delivery.
The normal length of pregnancy is from 37 to 41 weeks.
Postmaturity refers to any baby born after 42 weeks gestation or 294 days past the first day of the mother's last menstrual period.