The Prenatal Care Schedule

Contents

1. The first visit sets the baseline
2. The middle and late visits repeat the same checks
3. The number of visits is under review

Candace Cooley is a board certified obstetrician and gynecologist whose experience covers the care of pregnancies through to delivery, uncomplicated ones and those at high risk, and the instrument that organizes such care is a calendar. Prenatal care, a term that simply means care before birth, is delivered as a fixed sequence of appointments laid across roughly 40 weeks. The Office on Women’s Health gives the usual spacing for an uncomplicated pregnancy: a visit each month from week 4 through week 28, two a month from week 28 through week 36, and one a week from week 36 until birth. Women whose pregnancies are high risk are seen more often.¹ The calendar is mapped onto three trimesters, which the same agency places at weeks 1 to 12, 13 to 28 and 29 to 40, counted from the first day of the last normal period.²

Figure

The typical visit calendar

1. 01
   Weeks 4 to 28One visit a month.
2. 02
   Weeks 28 to 36Two visits a month.
3. 03
   Week 36 to birthOne visit a week.

The first visit sets the baseline

The opening appointment is the longest. The MedlinePlus Medical Encyclopedia advises arranging it soon after a pregnancy is known, and describes a visit built around questions about medicines, habits and health history, a Pap test and cultures for infection, and a discussion of diet, exercise, sleep and the common symptoms ahead. Blood is drawn for a set of tests called the prenatal panel, which includes a complete blood count, blood type and Rh screen, rubella immunity, hepatitis and HIV.³ The encyclopedia also notes that a first trimester ultrasound is used to estimate the due date, often with a probe placed in the vagina at this stage, and that the clinician will listen for the fetal heartbeat even though it usually cannot be heard or seen before about 6 to 7 weeks.³ Later first trimester visits are briefer: the woman is weighed, her blood pressure is taken, fetal heart sounds are checked and a urine sample is tested, and each visit ends with a word on what to expect before the next one. How those early scans work is described in obstetric ultrasound.

Other public sources list much the same contents. Patient guidance from the Oklahoma Health Care Authority, based on ACOG’s standards of care, adds a mouth and teeth examination, a breast and pelvic examination, temperature and height, counseling on daily prenatal vitamins, and teaching about danger signs and healthy eating.⁴ The Office on Women’s Health describes the same first visit as a full physical examination with blood tests and a calculated due date, and lists the infections and immunities checked at the start.¹ NIH MedlinePlus Magazine summarizes prenatal visits in general as a physical examination, weight checks and a urine sample, with blood tests and imaging such as ultrasound added as needed, and links early and regular care with fewer complications.⁵

Figure

The first visit and the visits after it

	First visit	Later visits
Focus	Questions about the woman and her health	Whether mother and baby are healthy
Examination	Full physical exam, including breast and pelvic exams and a Pap test	Physical exams as needed
Measurements	Blood pressure, temperature, weight and height	Weight and blood pressure, the baby's growth and heart rate
Tests	Blood and urine tests, and voluntary HIV testing	Special tests when needed

The middle and late visits repeat the same checks

After the first appointment the visits become shorter and more uniform. Most, according to the Office on Women’s Health, include a blood pressure and weight check, a check of the baby’s heart rate, and a measurement of the abdomen to follow the baby’s growth, with routine tests along the way for anemia, gestational diabetes and infection.¹ The MedlinePlus encyclopedia explains the purpose of the urine sample taken at visits: sugar or protein in it can point to gestational diabetes or to high blood pressure caused by pregnancy, the second of which is the concern behind preeclampsia.³

Some checks are tied to particular weeks. Women without risk factors are usually tested for gestational diabetes between weeks 24 and 28, a window that an NICHD study suggested may come too late, since fetal weight differences were measurable by week 28 and linked to maternal glucose from as early as week 10.⁶ After week 28 the Office on Women’s Health suggests that women keep track of the baby’s movements each day, so that a decrease is noticed; in the counting method it describes, done in the evening when the fetus tends to be active, most women feel ten movements within about 20 minutes.¹ The development behind the calendar is laid out week by week in the agency’s guide to the stages of pregnancy: movement felt by about 20 weeks, lungs formed but not working at 24, rapid weight gain around 32, and full term at 39 weeks, by which point most babies present head down. The same guide notes that near the due date the cervix thins and softens, which the clinician checks with a vaginal examination, and it flags sudden or extreme swelling or rapid weight gain in the later trimesters as possible signs of preeclampsia.² For the minority who have not, the options are covered in breech presentation and external cephalic version.

Ultrasound sits across the whole sequence. A 2007 CBS News segment described scans as tools for monitoring fetal health rather than snapshots, while noting that they cast a wide net and can raise questions that a follow up scan often settles.⁷ Throughout, the Office on Women’s Health draws a line that applies to every test on the calendar: screening tests estimate risk rather than diagnose, so a result outside the expected range is a prompt to gather more information rather than a finding in itself.¹

Figure

Visits counted against services delivered

office visits in the usual American schedule

12 to 14

guideline services received on average

6 of 8

visits made no meaningful difference to services received

5 or 15

The number of visits is under review

The calendar itself is old, and its value is now being questioned. Writing in STAT in 2021, two researchers noted that most pregnant people in the United States still receive 12 to 14 individual office visits, more than in France or the Netherlands, adding up to nearly a week of missed work or child care, and that the structure has hardly changed since the 1940s. In their analysis of nearly 180,000 pregnancies covered by a commercial insurer from 2016 to 2019, women received on average six of eight services recommended by guidelines, such as urine cultures, ultrasounds, diabetes screening and whooping cough vaccination, and there was no meaningful difference in services received between women with five visits and women with fifteen. Younger mothers, women with more complications and rural women were less likely to receive at least six of the eight.⁸ The authors described the basic aims of prenatal care as healthy outcomes for mother and child and trust between expectant mothers and their clinicians, noted that the pandemic had pushed clinicians to rethink the in person model, and argued that counting visits had become a stand in for quality, and pointed to group visits and mixed in person and virtual schedules as alternatives that deliberately reduce the count.⁸

Several questions remain open. Whether fewer, better targeted visits serve women as well as the traditional calendar has not been settled by the research to date, and the STAT authors called for measures that track whether medical and social needs are met rather than how often a woman is seen.⁸ Whether diabetes screening should move earlier is still being studied.⁶ And the calendar describes an uncomplicated pregnancy; women with higher risk are seen more often, sometimes by a specially trained doctor.¹ The schedule that fits any one pregnancy is worked out between the expectant mother and the clinician caring for her.