The 17th week often brings the comfort of the second trimester. Many experience renewed energy, moving past the intense symptoms of the first few months. This stage is frequently called the “honeymoon” phase, marking a significant phase of development for the fetus and noticeable physical changes for the parent.
Fetal Growth and Development Milestones
At 17 weeks, the fetus is approximately the size of a turnip or a pear, measuring 13 to 20.4 centimeters in length and weighing 113 to 181 grams. The body is rapidly catching up to the head, making the overall proportions appear more balanced. Growth is supported by the maturing placenta and the umbilical cord, which efficiently transports nutrients and oxygen.
A major developmental shift is the transformation of the skeletal structure. Soft cartilage is beginning ossification, providing a defined framework for the growing limbs. The fetus is also starting to deposit body fat beneath the thin skin, beginning insulation important for temperature regulation after birth.
Sensory development is progressing rapidly, particularly hearing. The inner ears are developing, and the fetus can perceive internal sounds, such as the parent’s heart beat and digestion. While the eyelids are still fused shut, the eyes can move slightly. Fingerprints and toenails are developing on the tiny digits.
Maternal Physical and Hormonal Changes
The mid-second trimester often brings increased energy and appetite, a welcome change from first-trimester fatigue and nausea. The body is producing a substantial volume of blood, which can lead to lightheadedness or dizziness when moving quickly. Accelerated growth of the uterus means weight gain picks up pace, requiring 300 to 400 calories daily to support fetal development.
As the uterus expands out of the pelvis, it pulls on the round ligaments supporting the womb. This stretching can result in sharp, brief pains in the lower abdomen or groin, known as round ligament pain. This discomfort is often triggered by sudden movements, like coughing or sneezing. Managing this involves moving more slowly and gently stretching.
Hormonal fluctuations and skin stretching lead to several common changes. Some may notice a dark vertical line down the center of the abdomen, called the linea nigra, a temporary change in pigmentation. Increased hormones can cause melasma, or the “mask of pregnancy,” manifesting as dark patches on the face. Increased vaginal discharge, known as leukorrhea, is typical as blood flow to the pelvic area rises.
Preparing for Upcoming Appointments and Quickening
At 17 weeks, many people anticipate “quickening,” the term for the first noticeable fetal movements. These initial movements are usually felt as subtle flutters, bubbles popping, or a gentle swishing sensation rather than distinct kicks. Experienced parents might feel these sensations earlier, but most first-time parents recognize quickening between 18 and 24 weeks.
This awareness of movement confirms the fetus’s activity. Looking ahead, this is the ideal time to schedule the mid-pregnancy anatomy scan, sometimes called the morphology scan. This detailed ultrasound is commonly performed between 18 and 22 weeks, with providers recommending the 19th or 20th week for the clearest imaging.
The anatomy scan is a comprehensive check of the fetus’s physical development, examining all major organs, limbs, and the position of the placenta. Prepare a list of questions for the provider regarding any concerns. Finalize the choice of hospital or birthing center for delivery, ensuring administrative arrangements are in place.