The second trimester of pregnancy runs from week 13 through week 27. It covers the middle three months of pregnancy and is often called the “honeymoon phase” because many of the toughest early symptoms fade while the baby undergoes rapid development. Here’s what to expect during these 15 weeks.
How Pregnancy Trimesters Break Down
Pregnancy is divided into three trimesters of roughly 13 weeks each. The first trimester covers weeks 1 through 12, the second trimester spans weeks 13 through 27, and the third trimester runs from week 28 until delivery (typically around week 40). Weeks are counted from the first day of your last menstrual period, not from the date of conception, which is why the numbering can feel slightly off.
The second trimester lines up roughly with months four, five, and six of pregnancy. Because calendar months and four-week blocks don’t align perfectly, you’ll sometimes see slight variations in how sources define the cutoffs. The 13-to-27 range is the standard used by most major medical organizations.
Why the Second Trimester Feels Different
For many people, the nausea and exhaustion of the first trimester ease significantly once the second trimester begins. Energy levels often rebound, and the worst of morning sickness is typically behind you. That combination is why this stretch of pregnancy has its “honeymoon” reputation.
That doesn’t mean symptoms disappear entirely. As your uterus grows to accommodate the baby, you may notice lower back pain, mild tightness in your belly (called Braxton Hicks contractions), and leg cramps that tend to strike at night. Hormonal shifts can cause skin changes too: darker patches on the face, a dark line running down the center of your belly, stretch marks, and tiny spider veins on the face or legs. Stuffy noses, nosebleeds, and bleeding gums during brushing are all common because increased blood volume causes tissues to swell. You may also notice more vaginal discharge, which is normal as long as it’s clear or white and doesn’t have a strong odor.
Fetal Development Week by Week
The second trimester is when your baby transitions from a small, developing embryo into a recognizably human form with functioning senses. Growth is dramatic during these weeks.
Around week 18, the baby’s ears begin to stand out on the head and hearing may start. By week 19, a greasy, cheese-like coating called vernix starts to form over the skin, protecting it from the amniotic fluid. By week 26, eyebrows and eyelashes have formed and the eyes are developed, though they may not open for another couple of weeks.
At the start of the second trimester, your baby is roughly the size of a lemon. By the end of week 27, the baby is considerably larger and more proportioned, with defined fingers and toes, facial features, and the ability to respond to sound and light.
Feeling Your Baby Move
One of the most anticipated milestones of the second trimester is quickening, the first time you feel your baby move. If you’ve been pregnant before, you may notice these fluttery sensations as early as 16 weeks. First-time mothers typically don’t feel movement until closer to 20 weeks. Early movements often feel like bubbles, gentle taps, or a rolling sensation, and they become more distinct and stronger as the weeks progress.
Key Screenings and Tests
Two major screenings happen during the second trimester. The first is the anatomy scan, an ultrasound typically performed around week 20. During this appointment, a technician takes detailed images and measurements of the baby’s heart, brain, spine, kidneys, lungs, stomach, intestines, limbs, and facial features. They also check the fetal heart rate, blood flow through the umbilical cord, the position of the placenta, the amount of amniotic fluid, and your cervix. This scan is also when many parents learn the baby’s sex if they choose to.
The second major screening is the glucose challenge test, performed between weeks 24 and 28 to check for gestational diabetes. You’ll drink a sugary solution and have your blood drawn afterward to measure how your body processes the sugar. If results come back elevated, a longer follow-up test confirms whether gestational diabetes is present. This condition is manageable but needs to be identified so it can be monitored for the rest of the pregnancy.
Weight Gain Guidelines
Weight gain picks up during the second trimester as the baby, placenta, and amniotic fluid grow. If you were at a healthy weight before pregnancy, the recommended pace is between half a pound and one pound per week during the second and third trimesters. Your provider may adjust that target based on your starting weight. Gaining too little or too much can both affect outcomes, so this is something worth tracking loosely rather than obsessing over.
Warning Signs to Watch For
While the second trimester is generally the most comfortable stretch of pregnancy, certain symptoms need immediate attention. Vaginal bleeding that’s more than light spotting, fluid leaking from the vagina, or foul-smelling discharge all warrant a call to your provider. The same goes for severe or sudden belly pain, a headache that won’t go away or comes with vision changes, extreme swelling of the hands or face (especially if you can’t bend your fingers or open your eyes fully), and a fever of 100.4°F or higher.
Once you start feeling the baby move regularly, pay attention to changes in that pattern. A noticeable decrease in movement or a stop in movement is worth reporting. Other red flags include sudden shortness of breath, chest pain or a racing heartbeat, severe swelling or redness in one leg or arm, and being unable to keep fluids down for more than eight hours. These symptoms don’t always signal something serious, but they overlap with conditions like preeclampsia, preterm labor, and blood clots that are best caught early.