Among the many changes that occur during pregnancy is lightening, the physical shifting of your baby's body that takes place shortly before labor. Understanding the facts about lightening, including what it is, what it means and how it might affect your body, helps you recognize this pregnancy milestone when it happens.
The Facts
From the first day of your last period to the estimated day of delivery, pregnancy typically lasts 40 weeks. During the bulk of this time, your unborn baby floats in your uterus, fed through the umbilical cord and surrounded by a warm bath of amniotic fluid. At some point during the last three to four weeks of pregnancy, the baby's body drops into your pelvic cavity, the bony structure that marks the entrance to the birth canal. Called lightening or "dropping," this physical movement of the baby's body causes your belly to shift downward and angle forward.
Time Frame
The time at which lightening occurs varies depending on multiple factors, including whether this is your first gestation. As a rule, most women pregnant with their first baby experience lightening two to four weeks before the birth. If you've given birth before, expect your baby to drop into the pelvic cavity later during gestation, possibly even as late as the beginning of labor. Because lightening sometimes occurs very late in pregnancy, some women don't even notice when it happens, which is normal.
Features
The downward movement of your unborn baby's body toward the birth canal produces multiple changes in your body. For most women, the most noticeable change is an increase in the need to urinate. This desire to void more frequently comes about because the baby's body now presses on top of your bladder. Some women also notice increased pelvic pressure or tingling and difficulty walking. On the bright side, heartburn might become a thing of the past. You also should be able to breathe better and eat larger meals now that the baby no longer pushes against your stomach and lungs.
Considerations
Once lightening has occurred, your obstetrician or midwife typically has a better idea regarding how your labor will progress. Most babies drop with their heads down, which puts them headfirst at the entrance of the birth canal, the perfect delivery position for an uncomplicated vaginal birth. But some babies drop bottom-first, which increases your chances of having a breech delivery or cesarean section once your baby's head is engaged. If this bottom-first position occurs, your pregnancy care provider might attempt to reorient the baby's body into a headfirst position to improve your chances of having an uncomplicated delivery.
References
- "The Encyclopedia of Women's Health"; Christine Ammer; 2009
- "The Mayo Clinic Guide to a Healthy Pregnancy"; Roger Harms; 2004
- "The Complete Idiot's Guide to Pregnancy and Childbirth"; Dr. Michele Isaacs Gliksman, et al.; 2010
- "Pregnancy Day by Day"; Andrew Loughney, et al.; 2009
- "Maternal and Child Health Nursing"; Adele Pillitteri, RN; 2009
