Week 25: The Baby Starts Listening Back

The baby starts listening back this week. If you have not done a full read-aloud test of the list, this is the week; the phonetic patterns that feel timeless describe what to listen for. Up to now hearing has been passive; from week 25 on, voices the baby hears repeatedly will be voices the baby recognizes after birth. The baby has been able to hear for a while, but this week the response gets reliable: a door slams, a voice rises, a dog barks somewhere in the apartment, and inside you a small body startles, twists, or settles depending on context. The conversation between you and the baby has gone from one-directional to genuinely two.

It is also the week your uterus, helpfully, reaches the size of a soccer ball. Pregnancy passes through a lot of clothes-shopping milestones, but the soccer-ball one is the one that makes most people finally accept that maternity leggings are not optional.

This week

The baby is now 13 inches long and weighs between 1½ and 1¾ pounds, the length of a rutabaga and the heft of a small bag of flour. The APA notes the baby "is slowly gaining some baby fat," which over the next month will start to fill in the wrinkled-skin look that ultrasounds at this stage often catch. By week 32, the baby will look notably plumper. By week 36, recognizably finished.

Hair, if there is any, is now showing color and texture, though the APA flags an honest caveat: "the color and texture could be seen at this point. However, it can change after your baby is born." Two-thirds of redheads were brunettes in the womb. Don't furnish a nursery around it.

The development worth slowing down for this week is hearing. Cleveland Clinic notes that the fetus by this stage "can hear your heartbeat, your stomach rumble and your breathing", and the response to external sound becomes more consistent and patterned. Loud sounds may trigger a startle. A familiar voice may trigger stillness, the way a focused listener stops fidgeting. This is the week the baby starts paying attention, not just receiving signal.

The sleep-and-wake rhythm is also beginning to consolidate. Most parents notice this as patterns in fetal movement, busy hours and quiet hours that recur day after day. It is the first real evidence that there is, in there, an inner schedule. Once you start tracking it, you cannot unsee it.

What's happening in your body

The APA describes the uterus this week as "approximately the size of a soccer ball," with the top "about halfway between your belly button and the bottom of your sternum." Your fundal height should be around 25 centimeters, give or take two. Cleveland Clinic's general guideline holds: your fundal height in centimeters should be "close to how far you are in pregnancy" from week 20 onward.

Three symptoms typically come into focus at week 25.

First, breath. The diaphragm has less room than it used to. Walking up two flights of stairs may now require a pause that did not exist last month. This is normal and will, paradoxically, ease in the last few weeks when the baby drops into the pelvis. Until then, take the elevator without explaining yourself.

Second, hands. Carpal tunnel symptoms, wrist pain, numbness, the pinky-side three fingers going to sleep at night, emerge in roughly a third of pregnancies and tend to start around now. The cause is fluid retention pressing on the median nerve. A wrist splint at night helps most people. It resolves after delivery.

Third, hair. Pregnancy hormones extend the growth phase of every hair follicle, which means more hair on your head than you have ever had, and, depending on body chemistry, more hair in places you would rather not. None of it is permanent. The shed begins around three months postpartum.

If you are between 24 and 28 weeks and haven't done your glucose screen yet, this is the most common week for it. The CDC notes most people are tested between 24 and 28 weeks. The result, almost certainly, will be fine. The minority who fail the one-hour screen go on to a three-hour test, and most of those pass.

What your partner can do

The specific thing partners can do this week is talk. Not as a wellness exercise. As an investment that pays out at the delivery.

The baby's hearing this week is consistent enough that a familiar voice begins to register as familiar. By the time the baby is born, they will recognize the people who have been talking near them. Newborns demonstrably orient toward their mother's voice within hours of birth, and there is reasonable evidence that consistent partner voices in the third trimester compound the same effect. The partner who has been quiet for six months can fix this in three with a habit of reading aloud, narrating their day, or just answering when the pregnant person says "the baby was kicking like crazy during your meeting."

The other thing partners can do this week is take the kick patterns seriously. The NHS guidance is precise on this: there is "no set number of movements you should feel each day – every baby is different," so the relevant signal is the baby's own pattern, not a universal threshold. The partner is often the second observer who notices when a pattern changes — when the active hour at night doesn't happen, when the busy stretch after breakfast went quiet. Pay attention. Ask. The NHS's specific advice if the pattern changes is to call your midwife. They are not annoyed by these calls. They prefer them.

One more, smaller suggestion: this week is also when many couples start the registry conversation. Resist the urge to make it a 200-item Amazon list. The honest truth is that the first three months of an infant's life require fewer objects than the internet wants you to believe. Bouncer, swaddles, white-noise machine, bassinet, car seat, diapers. Add things as you need them.

Names we love this week

Names with sound to them fit this week — voices the baby would have an easier time recognizing later.

• Soren — Danish "stern, severe" — a name that takes its time.
• Wren is a small songbird and a name that does not waste a syllable. It has been climbing US lists for ten years and reads as both modern and old — it appears on parish records from the 1600s.
• Lily is a flower and a sound, and after a decade in the top 50 it is finally settling into the kind of mid-tier evergreen that means a child will be one of a few Lilys in their grade, not the only one or one of eight.
• Hudson means "son of Hudd" in English. The river and the explorer both lend the name a steadiness most surname-derived first names do not have.
• Silas means "of the forest" in Latin. A New Testament name with a quietly rural feel that has been picked up by parents looking for a Biblical option that does not announce itself as one.
• Naomi means "pleasantness" in Hebrew. A name with one of the most beautiful etymologies in the canon — and the kind of two-soft-syllable sound that the baby, listening, will recognize.
• June is the month and the goddess and a one-syllable name that survived the mid-century Junes and came back fresh. Suited to a week when the body is unmistakably round.
• Caspian is a sea, a king from C.S. Lewis, and a name that has come into US use over the past decade. It carries a sense of distance — a name that sounds like somewhere worth going.

A small piece of advice for week 25: start saying your top three names out loud. Not in front of anyone. In the car, alone, paired with your last name, said normally, the way a teacher would call attendance. Names die or survive on the test of being said three thousand times. If a name embarrasses you in the car, it is not going to survive a parent-teacher conference.

Sources

• American Pregnancy Association — Week 25 of Pregnancy
• Cleveland Clinic — Fetal Development: Stages of Growth
• Cleveland Clinic — Fundal Height
• CDC — About Gestational Diabetes
• NHS — Your baby's movements