Third Trimester: Preparing for Birth (Weeks 28-40)

The third trimester — weeks 28 through 40 — is the home stretch. After the long journey of IVF treatment and months of pregnancy, you're now preparing for the moment you've been working toward: meeting your baby. This guide covers everything you need to know about the final trimester, with special considerations for IVF pregnancies.

1. Physical Changes in the Third Trimester

The third trimester brings the most dramatic physical changes as your baby grows rapidly and your body prepares for labor. Understanding what's normal can help reduce anxiety.

Weeks 28-32: Growth Acceleration

• Rapid weight gain: Your baby gains about half a pound per week. You may gain about 1 pound per week
• Shortness of breath: Your uterus now reaches your ribcage, compressing your diaphragm
• Braxton Hicks contractions: Irregular, usually painless "practice" contractions. They should not be regular, painful, or increase in frequency
• Heartburn intensifies: The growing uterus puts pressure on your stomach
• Sleep challenges: Finding a comfortable position becomes difficult. Left-side sleeping is recommended for optimal blood flow
• Swelling (edema): Mild swelling in feet and ankles is normal, especially at the end of the day

Weeks 33-36: Final Growth Phase

• Lightening (engagement): Your baby may drop lower into your pelvis, relieving pressure on your diaphragm but increasing pelvic pressure
• Increased urinary frequency: The baby's head presses on your bladder
• Pelvic discomfort: Your pelvic joints loosen in preparation for birth, which can cause discomfort
• Colostrum leakage: Some women notice small amounts of yellowish fluid from their breasts — this is the first milk

Weeks 37-40: Full Term

• Baby is now considered full term: Delivery at any point from 37 weeks is considered term
• Cervical changes: Your cervix may begin to soften, thin (efface), and open (dilate)
• Mucus plug: You may lose your mucus plug (bloody show) — a sign the cervix is beginning to change
• Nesting instinct: A surge of energy and urge to prepare your home is common

2. Creating Your Birth Plan

A birth plan is a written document that communicates your preferences for labor and delivery to your healthcare team. For IVF patients who have experienced years of medicalized care, creating a birth plan can be an empowering way to reclaim agency over your body and birth experience.

Key Elements to Consider

• Support people: Who will be with you during labor? (Partner, doula, family member)
• Pain management: Your preferences for epidural, IV medications, nitrous oxide, or unmedicated birth — with flexibility built in
• Labor environment: Preferences for lighting, music, mobility, eating/drinking during labor
• Interventions: Your thoughts on continuous fetal monitoring, IV fluids, artificial rupture of membranes, and episiotomy
• Labor positions: Preferences for freedom of movement, birthing ball, tub/shower, squatting bar
• Delivery: Preferences for pushing positions, mirror to view birth, delayed cord clamping, immediate skin-to-skin
• Newborn care: Preferences for vitamin K, eye ointment, hepatitis B vaccine, circumcision (if applicable)
• Feeding: Breastfeeding, formula feeding, or combination — and your preferences for lactation support
• Cesarean preferences (if needed): Clear drape, skin-to-skin in OR, partner present

IVF-Specific Birth Plan Considerations

• Placenta: Some IVF patients have an increased risk of placenta previa or accreta — your birth plan should acknowledge these possibilities
• Multiple gestation: If you're carrying twins or more, your delivery plan will differ significantly — discuss with your provider early
• Maternal age: Advanced maternal age may influence your provider's recommendations for induction timing
• Cord blood banking: IVF pregnancies may have considerations for delayed cord clamping if banking is desired

3. Signs of Labor: When to Go to the Hospital

Knowing the difference between early labor signs, false labor, and when to head to the hospital can save you an unnecessary trip — or ensure you arrive at the right time.

True Labor vs. Braxton Hicks

The 5-1-1 Rule: When to Go

Head to the hospital when contractions are:

• 5 minutes apart (from the start of one to the start of the next)
• Lasting 60 seconds (or longer)
• Following this pattern for at least 1 hour

Go to the Hospital IMMEDIATELY If:

4. Hospital Bag Checklist

Pack your hospital bag by week 35 — babies can arrive earlier than expected, and being prepared reduces stress when labor begins.

For You (Labor & Delivery)

• ID, insurance card, and hospital registration forms
• Birth plan — several printed copies
• Comfortable labor gown or loose clothing — something you don't mind getting messy
• Non-slip socks or slippers
• Robe — for walking the halls during early labor
• Lip balm and lotion — hospital air is very dry
• Hair ties or headband
• Phone charger with extra-long cord — outlets may be far from the bed
• Portable speaker and playlist — music can help create a calming environment
• Massage tools — tennis balls or massage roller for back labor
• Snacks and drinks — for early labor and for your partner
• Water bottle with straw

For You (Postpartum Recovery)

• Going-home outfit — loose, comfortable, maternity-sized (you'll still look about 5-6 months pregnant)
• Nursing bras and nursing pads — if planning to breastfeed
• Maternity underwear — high-waisted, comfortable, and dark colored
• Toiletries — toothbrush, toothpaste, deodorant, face wipes, dry shampoo
• Peri bottle — the hospital provides one, but some prefer their own
• Stool softeners — check with your provider first
• Nipple cream — lanolin or alternative

For Baby

• Going-home outfit — in newborn and 0-3 month sizes
• Swaddle blanket or receiving blanket
• Car seat — installed and inspected in advance. This is mandatory for hospital discharge
• Hat and socks/booties — newborns lose heat quickly
• Weather-appropriate outer layer — blanket for cold weather, sun shade for hot weather

For Your Partner/Support Person

• Change of clothes and comfortable shoes
• Toiletries
• Snacks and drinks — hospital cafeterias have limited hours
• Phone charger
• List of people to contact — with phone numbers
• Cash/change — for vending machines
• Pillow and blanket — hospital accommodations for partners can be sparse

5. Kick Counting: Monitoring Fetal Movement

Fetal movement is one of the best indicators of your baby's well-being in the third trimester. Formal kick counting, starting at 28 weeks, helps you track your baby's activity patterns and identify potential concerns early.

How to Perform Kick Counts

1. Choose a consistent time each day when your baby is typically active (often after meals or in the evening)
2. Get comfortable: Lie on your left side or sit in a reclined position
3. Focus on your baby's movements: Count each kick, jab, roll, or flutter. Do not count hiccups
4. Count to 10 movements: Record how long it takes to feel 10 distinct movements
5. Normal range: 10 movements within 2 hours is considered reassuring. Most babies achieve 10 movements in under 30 minutes

Common myths about decreased movement:

• Myth: "Babies move less near the end of pregnancy because they run out of room." Fact: While the type of movement may change (more rolls, fewer big kicks), the frequency should remain consistent. A significant decrease is never normal.
• Myth: "If the baby is sleeping, they won't move." Fact: Even during sleep cycles (20-40 minutes), babies have some movement. A 2-hour window accounts for sleep cycles.

6. Prenatal Appointment Schedule

Prenatal visits increase in frequency during the third trimester to monitor both your health and your baby's well-being more closely.

7. Complications to Watch For

While most pregnancies proceed without major complications, being aware of warning signs enables early intervention when needed. IVF pregnancies have a slightly higher risk for certain conditions.

Preeclampsia

A pregnancy complication characterized by high blood pressure and signs of organ damage, typically after 20 weeks. IVF pregnancies have approximately a 1.5-2x increased risk.

Warning signs: Severe headache that doesn't respond to acetaminophen, vision changes (spots, flashing lights, blurring), upper right abdominal pain, sudden swelling in face/hands, rapid weight gain.

Screening: Blood pressure is checked at every prenatal visit. Urine is tested for protein. Low-dose aspirin (81mg daily) starting at 12 weeks may be recommended for IVF patients as prevention.

Gestational Diabetes

Diabetes that develops during pregnancy, affecting how your cells use sugar. IVF pregnancies, particularly those using frozen embryo transfers with hormonal preparation, may have a slightly increased risk.

Screening: Glucose challenge test at 24-28 weeks. If abnormal, a 3-hour glucose tolerance test follows.

Management: Diet modification, blood sugar monitoring, exercise, and possibly insulin or medication.

Placenta Previa

The placenta partially or completely covers the cervix. IVF has a 2-3x increased risk of placenta previa compared to natural conception.

Detection: Identified on the anatomy scan. If present, follow-up ultrasounds monitor whether it resolves (most do as the uterus grows).

Management: Pelvic rest, no vaginal exams, C-section delivery if it persists at term.

Preterm Labor

Labor that begins before 37 weeks. IVF pregnancies, especially multiples, have a higher preterm birth rate.

Warning signs: Regular contractions before 37 weeks, low backache, pelvic pressure, vaginal discharge changes (watery, mucus-like, or bloody), cramping.

8. Delivery Options for IVF Pregnancies

Vaginal Delivery

Vaginal birth is the goal for the vast majority of IVF pregnancies. IVF alone is not a medical indication for cesarean section. Benefits include shorter recovery time, lower infection risk, and exposure to beneficial bacteria for the baby.

Cesarean Section (C-Section)

Approximately 32% of births in the United States are via C-section. IVF pregnancies have a slightly higher rate (~35-40%) due to associated factors:

• Maternal age: Older mothers have higher C-section rates regardless of conception method
• Multiple gestation: Twins and higher-order multiples are more common in IVF and more likely to be delivered via C-section
• Placenta previa: More common in IVF; requires C-section delivery
• Provider preference: Some providers may recommend C-section for IVF pregnancies perceived as "premium" or "precious" — this is not evidence-based
• Maternal request: Some IVF patients choose elective C-section after years of medicalized care

Induction of Labor

Labor induction (using medication or other methods to start labor artificially) may be recommended for IVF pregnancies, particularly at 39-40 weeks. The ARRIVE trial demonstrated that elective induction at 39 weeks for low-risk first-time mothers reduces C-section rates without increasing complications — a finding that influences many providers' recommendations.

9. Postpartum Preparation

The postpartum period — often called the "fourth trimester" — begins the moment your baby is born. Preparing in advance helps ease this transition.

Physical Recovery

• Vaginal birth recovery: Expect perineal soreness, bleeding (lochia) for 2-6 weeks, and possible hemorrhoids. Peri bottles, ice packs, and sitz baths help
• C-section recovery: Major abdominal surgery with a 6-8 week recovery. You'll need help with lifting, driving, and household tasks
• Breast changes: Milk typically "comes in" 3-5 days after birth. Engorgement, leaking, and nipple soreness are common initially

Emotional Health

• Baby blues: Mood swings, crying, and anxiety in the first 2 weeks after birth are normal and affect up to 80% of new mothers
• Postpartum depression/anxiety: If symptoms persist beyond 2 weeks or are severe, seek help. IVF patients may be at slightly higher risk due to the emotional toll of fertility treatment
• Identity transition: Moving from "infertility patient" to "mother" is a significant psychological shift that takes time

Practical Preparations (Do Before Delivery)

• Arrange help: Partner, family, friends, or postpartum doula for the first 2-4 weeks
• Meal prep: Freeze meals in advance or set up a meal train
• Set up feeding stations: Comfortable chair, water, snacks, phone charger, burp cloths within reach
• Pediatrician: Select one before delivery — they'll examine your baby in the hospital
• Lactation support: Know who to call if breastfeeding challenges arise (IBCLC lactation consultant)
• Pelvic floor therapy: Consider scheduling a postpartum evaluation

10. Frequently Asked Questions