21 Weeks Pregnant

Baby’s Development

Fetus ~25.5 cm (carrot), weight ~360 g [1]. Digestive system active: swallows amniotic fluid, absorbs water, kidneys excrete, intestines absorb sugars. Bone marrow begins producing blood cells (liver, spleen, bone marrow now share the load). Eyebrows and eyelids visible. Lips more defined. Lanugo covers body. Skin is less translucent, more pink. Movement: kicks, punches, rolls, hiccups. Sleep-wake cycles distinct. Responds to loud noises with startle reflex [2].

Pregnancy Symptoms

Energy still good. Symptoms: backache, heartburn (worsening), constipation, leg cramps, mild swelling, headaches, possible hemorrhoids, possible Braxton Hicks. Kicks regular and distinct. Uterus ~1 cm above navel. Possible round ligament pain flares with movement. Shortness of breath (diaphragm pressure). Snissing common. Possible restless legs (urge to move legs at night) [2].

Body Changes

Uterus ~1-2 cm above navel. Weight gain: 13-18 lbs by week 21 typical. Bump clearly visible. Possible stretch marks, linea nigra, melasma. Breasts 1.5-2 cup sizes up, colostrum may leak. Visible veins, possible varicose veins (legs, vulva). Skin may be oilier or drier than normal [2].

Tips for Week 21

• Address restless legs (if applicable) — iron, folate, magnesium may help. Stretch before bed, warm bath, massage. Avoid caffeine. Discuss with OB.
• Begin perineal massage (optional) — 5 min daily from week 34 helps reduce perineal tearing at birth. Not yet, but research technique, get oil (vitamin E, almond, coconut).
• Strength training — moderate weights, high reps, focus on posture muscles (back, glutes, core). Prevents back pain, prepares for carrying baby/car seat.
• Stay on top of hydration + fiber — 80-100 oz water, 25-30 g fiber/day. Reduces constipation, swelling, UTIs.

Things To Do (Checklist)

• Address restless legs (if present): iron, magnesium, stretch
• Start light strength training 2x/week
• Track hydration + fiber intake
• Research perineal massage technique
• Schedule glucose screening (24-28 weeks)
• Cyst + exercise: confirm no restrictions on running/lifting

Frequently Asked Questions

Q: I have leg cramps at night. Help? A: Common. Stretch calves before bed (wall push-up), magnesium glycinate (with provider OK), stay hydrated, avoid pointing toes. Cramp = immediate stretch, dorsiflex foot [1].

Q: Can I lift weights? A: Yes, moderate weight is fine. Modify: lighter weight, more reps, avoid Valsalva (hold breath), avoid supine lifts after 20 weeks. Compound movements OK. Listen to body [2].

Q: Why am I getting varicose veins? A: Increased blood volume + hormone relaxation + uterine pressure on veins. Prevention: compression socks, elevate legs, don’t cross legs, exercise. Often resolve post-birth [1].

For Dads

• Cook meals rich in iron + protein — beef, lentils, spinach, fortified cereal, pumpkin seeds. Helps with your partner’s blood volume + iron needs.
• Handle the “itch cream” duty — your partner may develop itchy belly (stretching skin). Cocoa butter, vitamin E oil, Bio-Oil, or shea butter. Apply nightly.
• Research and book hospital tour — most your area hospitals offer free tours 24-28 weeks. Washington, Eden, UCSF. Book soon; spots fill.
• Read The Expectant Father Ch. 17 — second trimester body changes, your role as support.
• Pray for digestive system development — swallowing, processing amniotic fluid, practicing for life outside.

Sources

1. ACOG — How Your Fetus Grows During Pregnancy
2. Mayo Clinic — 21 Weeks Pregnant
3. What to Expect When You’re Expecting — Heidi Murkoff (Chapters 13-14: Second Trimester)