Numbers and Graphs during Labor, Delivery, and Postpartum
I nerded out during labor and delivery and asked the doctors and nurses all kinds of questions about the monitors, graphs, and what all they were tracking. As a geek, I’m fascinated by the different numbers and their meaning. I’ve rounded some of them up here to share what I learned.
Fetal Heart Rate Monitor
The doctor typically places an external monitor on mom’s belly to track the baby’s heart rate. The heart rate is normally between 110-160 beats per minute. Depending on your situation and how labor is progressing, the doctor may take the fetal heart rate every 30 minutes, strap the device on to continuously monitor, or place an internal monitor if they are having trouble hearing the heartbeat externally.
Normally, fetal heart rate increases when the baby moves and during contractions. If this is not the case, the doctor or nurse may have mom change positions, give mom fluids through an IV, or give mom supplemental oxygen. Doctors commonly use these during labor and delivery.
Mom gets another monitor during labor to measure the frequency and intensity of contractions. Early in labor, this shows whether the contractions are regular and becoming stronger and closer together, indicating that labor is progressing. Later, doctors use the contraction monitor to determine if the baby’s heart rate is increasing during contractions, as mentioned above. Finally, during a vaginal birth, the doctor or nurse can use this to help tell mom when to push. This is especially helpful if mom is using pain relief options, such as an epidural, and may not be able to feel the contractions.
The top graph shows the fetal heart rate – the area in blue is the normal range. The bottom graph shows contractions. Here, we see the baby’s heart rate increases when mom has a contraction. Source
If labor has not started, or is not progressing, doctors may administer the drug Pitocin through an IV. It is a synthetic version of oxytocin, and triggers contractions, which can jump-start labor. About 40-50% of women in the US receive Pitocin during labor. Most hospitals start at a dosage of 2 microunits, monitor mom’s reaction, and increase the dosage every half hour as needed. Each hospital and patient has a different limit for the maximum dosage. You may hear a doctor or nurse say something like “Increasing Pit level to 6.”
Dilation, Effacement, and Station
During labor, a doctor or nurse may say something like 4, 75, -1. What are these three numbers?
The first number is the dilation of the cervix. A doctor measures this with a cervical exam, and reports how open the cervix is, in centimeters and reports a number from zero to ten. A cervix at 0 cm is fully closed. 10 cm means fully open and it is time to deliver the baby.
The second number is effacement of the cervix. A doctor measures effacement during a cervical exam and ranges from 0 to 100. The cervix needs to thin before the baby can be delivered. Zero percent effacement means that the cervix is at normal, pre-labor length. If the cervix is 100% effaced, it is very thin.
The third number is the station, or position of the baby’s head in relation to mom’s pelvis. The doctor also measures this during a cervical exam and reports the station, ranging from -3, -2, -1, 0, +1, +2, +3. The baby is higher up inside the uterus at negative numbers and is closer to delivery with positive numbers. Reference.
The Apgar test is used to quickly summarize the baby’s health after birth. It was developed by Virginia Apgar.
The Apgar score is determined by evaluating the newborn baby on five simple criteria on a scale from zero to two, then summing up the five numbers. The Apgar score ranges from zero to 10. The five criteria are summarized using words chosen to form a backronym (Appearance, Pulse, Grimace, Activity, Respiration).
Appearance- skin color
- 0: blue or pale
- 1: extremities blue, body pink
- 2: body and extremities pink
- 0: absent
- 1: less than 100 beats per minute
- 2: greater than 100 beats per minute
Reflex Irritability Grimace
- 0: no response
- 1: grimace on stimulation
- 2: cry on stimulation
- 0: none
- 1: some flexing of arms and legs
- 2: flexing of arms and legs that resist extension
- 0: absent
- 1: weak, irregular gasping
- 2: strong, robust cry
When I first started breastfeeding, I wondered how to tell if my baby was getting enough to eat. Luckily, the pediatricians, nurses and lactation consultants at the hospital explained that it’s pretty easy: I just have to keep track of how many wet and dirty diapers my baby makes every day. The simple way my doctor explained was that breastfed babies should produce:
- Day 1-2: 1-2 wet diapers and stools per day
- By Day 4: 6+ wet diapers and 3-4 stools per day
Of course, diaper counting isn’t completely accurate, and all newborns should see their pediatrician within 1-2 days of leaving the hospital so a doctor can assess their weight, alertness, responsiveness, and growth in length and head circumference. These will confirm if your baby is growing and getting enough milk.
I never thought about the fact that babies lose weight after birth, and then regain it within the first two weeks of life. While in the womb, the baby is “waterlogged ” with fluids, and their digestive tract has filled up. The baby loses weight as the fluid is lost. At the same time, for the first few days of after birth, mom produces colostrum for the baby, and the baby doesn’t really start to gain weight until mom’s milk comes in 2-4 days later. Typically, newborns lose 7-10% of their weight in the first few days of life and regain it within two weeks.
Hospitals and pediatricians are careful to monitor the baby’s weight daily while in the hospital to ensure they are gaining appropriately. On average, a newborn gains about half an ounce to one ounce every day for the first month (or about 1-2 pounds total). Typically, babies double their birth weight by five months (source)
The pediatrician will measure the baby’s weight, length, and head circumference, and report not just a number, but a percentile or curve. Scientists have taken a huge number of normal children and measured these things. If a child’s weight is at the 50th percentile, it means that out of 100 children, 50 will weigh more than your child and 50 will weigh less. Similarly, for the 75th percentile, your child will weigh more than 75 of the 100 children and less than 25.
Growth chart for girls from birth to 36 months.
It’s important to remember that the percentile itself isn’t important, it’s whether the baby stays in the same percentile over time. If the baby’s weight or length drops more than two percentile lines, then your pediatrician will work with you to understand what’s going on. If the baby goes up percentile lines, it is likely they are going through a growth spurt. More information on growth charts is available here.
The CDC publishes growth charts. I just might have printed one out to track my little one’s growth myself after each visit to the pediatrician!
I love learning about graphs and numbers, especially when it comes to my health and my baby’s health. Have any data you’d like help interpreting? Let me know in the comments, I’d love to research it and write about it in a future post!
Love graphs and data? Check out my post about Average Cost of Disposable Diapers per Year or my post on Disposable Diaper Brand Comparison for tons of graphs and charts! Or read about historical baby formula and hospital stays of the 1950’s that I’ve found!