Feeling Your Baby “Drop” during the Third Trimester
During the month before delivery, a woman may notice that her belly feels lower and that suddenly it’s easier to breathe. This feeling is because the baby has dropped, or descended lower into the pelvis. This movement is also called lightening. It typically happens two to three weeks before delivery in women who are having their first child. Those who have had children before may not drop until they’re in labor.
When dropping happens, you may find that you’re suddenly much more comfortable. Your uterus doesn’t press up on your diaphragm or stomach as much as it used to, so breathing is easier, and heartburn may improve. At the same time, however, you may feel more pressure in your vaginal area — many women feel heaviness there.
Some women report feeling strange, sharp twinges as the baby’s head moves and exerts pressure on the bladder and pelvic floor. Having the baby “drop” doesn’t predict when labor will happen.
You may not notice that you have dropped. During your prenatal visit, your doctor may be able to tell by an external or internal exam how low the baby’s head is and whether it’s engaged. The fetal head is engaged when it has reached the level of the ischial spines, which are bony landmarks in your pelvis that can be felt during an internal exam.
When the fetal head is at this level, it’s at zero station. Most practitioners divide the pelvis into descending stations from –5 to +5 (although some use –3 to +3).
Often at the beginning of labor, the head may be at –4 or –5 station (fairly high — sometimes called floating, because the fetal head is still floating in the amniotic cavity). Labor proceeds until the head descends all the way to +5, when delivery is about to begin.
If the baby’s head is engaged prior to labor, you’re more likely to deliver vaginally, although obviously there are no guarantees. Similarly, although a floating (unengaged) head isn’t every obstetrician’s dream, it doesn’t mean that you won’t have a completely normal delivery.
If you’re having your second child or more, the baby’s head may not engage until well into labor.