At 25 weeks pregnant, you’re solidly in the second trimester’s final stretch, with about 15 weeks to go. Your baby is roughly the size of an eggplant, weighing around 1.5 pounds and measuring about 13 inches from head to heel. This is a week of rapid sensory development for your baby and noticeable physical changes for you, from a growing belly to new aches that signal your body is working hard to support a bigger, more active passenger.
How Your Baby Is Developing
Your baby’s lungs are hitting important milestones right now. The cells responsible for producing surfactant, a substance that keeps the tiny air sacs in the lungs from collapsing, have been maturing since around 20 weeks. The structures that store surfactant first appeared between 20 and 24 weeks, and from here the amount of this critical substance steadily increases all the way to birth. Your baby won’t need those lungs to work yet, but this groundwork is essential for breathing air after delivery.
Hearing is coming online in a big way. By 24 weeks, the inner ear structures are developing rapidly, and around week 25 or 26, babies have been shown to respond to voices and noise from outside the womb. Your voice, your partner’s voice, music, even a loud door slam can all register now. The baby’s sensitivity to sound will keep improving over the coming weeks, so this is a fun time to talk or sing to your belly if you’re inclined.
Fat is also starting to fill out your baby’s skin, which has been wrinkled and translucent. Over the next several weeks, that stored fat will help regulate body temperature after birth and give your baby a plumper appearance.
Viability: A Meaningful Milestone
Twenty-five weeks marks a significant threshold for survival outside the womb. A large study of nearly 23,000 infants across 636 U.S. hospitals found that 82% of babies born at 25 weeks survived to hospital discharge. That’s a dramatic jump from earlier weeks (survival at 22 weeks is about 25%). Babies born this early still face serious challenges: only about 43% of those born at 25 weeks survived without severe complications, and the median hospital stay for survivors was 110 days. None of this is something you need to dwell on if your pregnancy is progressing normally, but it can be reassuring to know that modern neonatal care gives babies born at this stage a strong chance.
What Your Body Is Doing
Your uterus is now well above your belly button. Fundal height, the distance from your pubic bone to the top of your uterus, should measure close to the number of weeks you are pregnant, plus or minus 2 centimeters. So at 25 weeks, expect a measurement somewhere around 23 to 27 centimeters. Your provider will likely check this at upcoming appointments as a simple way to track your baby’s growth.
Lower back pain is common at this stage. Hormonal changes loosen the ligaments in your pelvis, and the growing weight of your uterus shifts your center of gravity forward, putting strain on your back. Braxton Hicks contractions may also appear as a mild tightening across your belly that comes and goes without a regular pattern. These are your uterus practicing for labor and are generally harmless.
Skin and Circulation Changes
Pregnancy hormones increase the pigment-producing cells in your skin. You might notice brown or grayish patches on your face (called melasma) or a dark vertical line running down the center of your belly. Stretch marks can appear on your belly, breasts, thighs, or buttocks as your skin stretches to accommodate growth. Small spider veins, tiny visible blood vessels on your face or legs, are another common side effect of the increased blood volume your body is carrying.
That extra blood volume also affects your nose. The lining inside your nasal passages can swell, leaving you congested or prone to nosebleeds. Your gums may bleed more easily when you brush or floss. Neither is usually cause for concern, but both can be annoying.
Leg Cramps and Sleep Disruption
Leg cramps tend to become more frequent as pregnancy progresses, often striking at night. Staying hydrated, stretching your calves before bed, and keeping up your activity level during the day can help. If cramps are waking you regularly, mention it to your provider since it can sometimes signal low magnesium or other mineral imbalances.
Sleep itself gets trickier around this point. Side sleeping is the recommended position because lying on your back puts pressure on the inferior vena cava, the large vein that returns blood from your lower body to your heart. This can reduce blood flow to you and the baby. The left side is considered ideal because it maximizes blood flow to the placenta and improves kidney function. Tucking a pillow between your knees and another under your belly can help you stay comfortably on your side through the night.
Feeling Your Baby Move
By 25 weeks, most women are feeling regular kicks, rolls, and flutters. Movement patterns at this stage can still be unpredictable since your baby is small enough to shift position frequently and has periods of deep sleep. Formal kick counting is typically recommended starting at 28 weeks, when a lack of movement becomes a more reliable signal that something may be wrong. The general guideline at that point is to feel 10 movements (kicks, flutters, swishes, or rolls) within two hours.
For now, simply getting familiar with when your baby tends to be active is useful. Many women notice more movement after meals or when lying down in the evening. If you go an unusually long stretch without feeling anything and it worries you, drinking something cold and lying on your side often prompts a response.
Glucose Screening Is Coming Up
If you haven’t already been tested, gestational diabetes screening typically happens between 24 and 28 weeks, so it may be scheduled at your next appointment. The standard approach is a glucose challenge test: you drink a sugary solution, wait one hour, then have your blood drawn. If those results come back elevated, you’ll take a longer, more detailed follow-up test. Women with known risk factors (family history of diabetes, higher BMI, prior gestational diabetes) are often screened earlier in pregnancy.
Iron and Nutrition
Your iron needs during pregnancy are 27 milligrams per day, nearly double what non-pregnant women require. Your body is producing significantly more blood to support the placenta and your baby, and iron is essential for making the hemoglobin that carries oxygen in that blood. Many prenatal vitamins contain this amount, but your diet matters too. Red meat, spinach, lentils, and fortified cereals are all solid sources.
Iron deficiency anemia is one of the most common pregnancy complications, and the signs can sneak up on you because they overlap with normal pregnancy fatigue. Watch for extreme tiredness that feels disproportionate to your activity level, weakness, dizziness, shortness of breath, or unusual cravings like wanting to chew ice. Your provider will check your blood counts during routine labs, but flagging these symptoms early can help you get treatment sooner if your levels have dropped.
What to Focus on This Week
Practically speaking, 25 weeks is a good time to settle into habits that will serve you through the third trimester. If you haven’t already, experiment with pillow arrangements for side sleeping before your belly gets much bigger. Stay consistent with iron-rich foods. Keep moving, even if it’s just daily walks, since regular activity helps with back pain, leg cramps, sleep quality, and mood.
If your glucose test is coming up, there’s nothing special you need to do to prepare for it (fasting is not required for the initial one-hour screening). And if your baby’s kicks feel like full-on acrobatics some days and quieter on others, that’s completely normal at this stage. The patterns will become more predictable over the next few weeks as your baby grows and has less room to somersault.