What Happens at Your 28-Week Pregnancy Appointment

Your 28-week visit is when your doctor screens you for gestational diabetes and checks how your baby is growing

At 28 weeks, you're in your third trimester, and your appointment shifts focus. Your provider will test your blood sugar response with a glucose tolerance test, measure your belly to track the baby's size, check your blood pressure and urine, and listen to the baby's heartbeat. You'll also discuss any symptoms you're having — swelling, back pain, heartburn, sleep trouble — and get information about what to watch for in the weeks ahead. Most visits last 20 to 30 minutes.

This is also when many practices screen for anemia again and may discuss your birth plan, pain management options during labor, and what happens if you go into preterm labor. If you haven't had your Rh antibody screen yet and you're Rh-negative, you'll receive a RhoGAM injection to prevent sensitization. Bring a list of questions — this is a good time to ask about labor induction, cesarean delivery, or anything else on your mind.

Key Takeaways

• The glucose tolerance test (usually a 1-hour test with a sugary drink) screens for gestational diabetes, which affects how your baby develops and your delivery options.
• Your provider measures your fundal height (the distance from your pubic bone to the top of your uterus) to confirm the baby is growing at the expected rate.
• Blood pressure, urine, and weight checks happen at every visit and help catch preeclampsia or other complications early.
• If you're Rh-negative and haven't had RhoGAM yet, you'll receive it now to prevent your immune system from attacking your baby's red blood cells.

The glucose tolerance test and what the results mean

You'll drink a sweet liquid (usually 50 grams of glucose) and have your blood drawn one hour later. You don't need to fast, and you can eat normally that day. The test measures how quickly your body processes sugar. A result under 140 mg/dL is considered normal; results between 140 and 199 mg/dL may mean you need a longer follow-up test; results of 200 mg/dL or higher usually mean gestational diabetes is present.

If your first test is borderline, your provider will order a 3-hour glucose tolerance test, which requires fasting overnight and involves drinking a larger glucose dose with blood draws at one, two, and three hours. About 15 to 25 percent of pregnant people have a borderline first result, so this doesn't mean something is wrong — it's a standard next step. If the 3-hour test confirms gestational diabetes, your provider will refer you to a dietitian and may recommend blood sugar monitoring at home.

Gestational diabetes usually goes away after delivery, but it does affect how your baby grows and can increase the risk of complications during labor. Managing it with diet, exercise, and sometimes insulin keeps both you and your baby safer. Your provider will explain what monitoring looks like if you receive this diagnosis.

Fundal height measurement and what it tells your provider

Your provider will measure from your pubic bone to the top of your uterus with a soft tape measure. At 28 weeks, fundal height is usually around 26 to 30 centimeters — roughly matching your week of pregnancy, give or take 2 centimeters. This simple measurement tracks whether your baby is growing at the expected pace and whether the amount of amniotic fluid is normal.

If your fundal height is smaller than expected, your provider may order an ultrasound to check the baby's size, the placenta, and fluid levels. If it's larger than expected, it could mean you're further along than thought, you're carrying more than one baby, or there's extra amniotic fluid. None of these findings automatically means something is wrong — they're reasons to look more closely with ultrasound.

Blood pressure, urine, and weight checks

These three measurements happen at every prenatal visit and are your provider's early warning system for complications. High blood pressure (especially if it's new or rising) can signal preeclampsia, a serious condition that requires close monitoring or early delivery. Protein or glucose in your urine can also point to preeclampsia or gestational diabetes. Weight gain that's sudden or much faster than expected can be a sign of fluid retention related to preeclampsia.

Normal weight gain by 28 weeks is about 17 to 24 pounds if you started at a healthy weight, though this varies based on your starting point and whether you're carrying multiples. Your provider will discuss what's normal for you specifically. If any of these measurements are outside the expected range, your provider will explain what it means and what the next step is.

Rh-negative status and the RhoGAM injection

If your blood type is Rh-negative and your baby's father is Rh-positive (or his status is unknown), there's a small chance your baby is Rh-positive. During pregnancy, fetal blood can mix with yours, and if it does, your immune system may treat the baby's red blood cells as foreign and attack them. This sensitization usually doesn't harm your current pregnancy but can cause serious problems in future pregnancies.

RhoGAM is an injection of antibodies that prevents your immune system from reacting to Rh-positive fetal blood. You receive it at 28 weeks as a standard dose (300 micrograms in the US), and again within 72 hours after delivery if your baby is confirmed to be Rh-positive. The injection is given in your arm or buttock and takes less than a minute. Side effects are rare — mild soreness at the injection site is the most common.

Discussing your birth plan and labor preferences

Your 28-week visit is a good time to start talking about how you want labor and delivery to go. This includes pain management options (epidural, nitrous oxide, movement and positioning, continuous support from a partner or doula), your feelings about induction or cesarean delivery if complications arise, and what you want to happen immediately after birth (skin-to-skin contact, delayed cord clamping, breastfeeding). Your provider can explain what's available at your hospital or birth center and what the evidence shows about different choices.

You don't need to have all the answers now — birth plans often change once labor starts. But having these conversations early means you and your provider are on the same page, and you have time to think through what matters most to you. If you're planning to use a birth doula or have specific cultural or religious practices you want honored, this is the time to mention it.

What to bring and how to prepare

Bring your insurance card, photo ID, and any records from previous pregnancies or medical conditions. If you've been tracking symptoms (swelling, bleeding, severe headaches, vision changes, chest pain), write them down so you don't forget to mention them. Wear comfortable clothing that lets your provider access your belly and arm for blood pressure.

You don't need to fast for the glucose tolerance test, so eat a normal breakfast or lunch beforehand. Some people feel lightheaded after drinking the glucose solution, so eating something small an hour or two before the test can help. If you have questions about your pregnancy, your symptoms, or what to expect in the coming weeks, write them down — you're more likely to remember to ask if you have a list.

Frequently Asked Questions

What if I fail the glucose tolerance test?

A borderline result on the 1-hour test doesn't mean you have gestational diabetes — it means you need the 3-hour test to be sure. Even if the 3-hour test is positive, gestational diabetes is manageable with diet and exercise, and many people never need insulin. Your provider will refer you to a dietitian who specializes in pregnancy.

Can I skip the RhoGAM injection if I'm Rh-negative?

If your baby's father is confirmed to be Rh-negative, you don't need it — your baby will be Rh-negative too. If his status is unknown or positive, RhoGAM is strongly recommended to protect future pregnancies. Talk to your provider about your specific situation.

What does it mean if my fundal height is off?

Fundal height that's smaller or larger than expected is a reason to do an ultrasound, not a diagnosis of a problem. It could mean you're further along or earlier than thought, you're carrying multiples, there's extra fluid, or the baby is simply smaller or larger than average. Ultrasound will show what's actually happening.

Is the glucose drink safe for my baby?

Yes. The glucose tolerance test uses a small amount of sugar that doesn't harm your baby. It's a screening tool only — the sugar doesn't stay in your system long enough to affect fetal development or cause gestational diabetes on its own.

What should I do if I have severe swelling or headaches before my appointment?

Call your provider right away rather than waiting for your 28-week visit. Sudden swelling, severe headaches, vision changes, or chest pain can be signs of preeclampsia, which needs prompt evaluation. Your provider has an on-call line for urgent questions between appointments.