Fetal hiccups often start early in pregnancy, long before you can feel any fetal movement. Hiccups, a reflex action, occur in one in 50 babies, according to Michelle Murray, PhD, RNC in the book, "Antepartal and Intrapartal Fetal monitoring: Third Edition." Hiccups generally are benign but in very rare cases may indicate fetal problems.
Definition
A hiccup is an involuntary movement of the diaphragm, the muscle used for breathing. Hiccups in a fetus may help strengthen the diaphragm to prepare it for breathing movements after birth, Babies Online states.
Timing
Hiccups appear very early in pregnancy, as early as eight to nine weeks, soon after the arms and legs develop. Hiccups can cause the whole fetal body to jump up and down in the amniotic fluid, lead author Karen Adolph of New York University reports in "Developmental Science" published in 2005. Hiccups occur frequently in the first trimester as demonstrated by ultrasound, often occurring every two to three seconds, "Ultrasound in Obstetrics and Gynecology" edited by Eberhard Merz reports. By the third trimester, when you can feel fetal hiccups, they occur less frequently, with an episode only two to four times in a 24-hour period, the textbook adds.
Causes
Hiccups often occur as a reflex reaction to fetal swallowing or breathing, according to Labor of Love. Lead author Jason Collins, M.D., of the Pregnancy Institute states that cord compression may cause frequent fetal hiccups and that daily occurring fetal hiccups require ultrasound evaluation to check for possible cord compression.
Diagnosis
Sometimes what feel like hiccups to a pregnant woman may actually be fetal seizures, Dr. Murray reports. Regular, rhythmic, intense movements or twitches that occur several times a minute may indicate fetal seizure activity. Fetal ultrasound or fetal electroencephalogram may show signs of seizures.
Considerations
Many babies have hiccups in the womb, and in most cases, hiccups are nothing more than an involuntary, harmless reflex. In rare cases, hiccups may be caused by problems with the umbilical cord, or what appears to be hiccups may actually be seizure activity. If you're concerned that your baby hiccups more than normal, a fetal ultrasound to check activity may set your mind at ease.
References
- Developmental Science: Physical and Motor Development
- Pregnancy Institute: Silent Risk: Issues About the Human Umbilical Cord
- The Labor of Love: Is it OK For My Unborn Baby to Have Hiccups so Often?
- "Antepartum and Intrapartal Fetal Monitoring;" Michelle Murray, PhD; Springer Publishing Company; 2006
- "Ultrasound in Obstetrics and Gynecology;" Eberhard Merz; Thieme; 2004
