What is happening to your body and your baby each week of pregnancy — and what you should be doing, testing, and scanning at every stage. A practical guide for Nigerian women, from Mascot Healthcare, Akoka.
Conception occurs at week 2 (if ovulation was day 14 of a 28-day cycle). The fertilised egg implants into the uterine wall at week 3–4. By week 4, the embryo is the size of a poppy seed. A urine pregnancy test turns positive from week 4 (when your period would be due). A blood beta hCG test can detect pregnancy a few days earlier.
The heart begins beating at approximately week 6. An early viability scan at 6–8 weeks confirms: the pregnancy is in the uterus (not ectopic), there is a fetal heartbeat, and gives the earliest date estimate. If you have had a previous ectopic pregnancy or miscarriage, or have pain or bleeding, a scan at 6–7 weeks is urgent.
Common symptoms: nausea (morning sickness), breast tenderness, fatigue, frequent urination, heightened sense of smell. All are caused by rising hCG and progesterone — peak at 8–10 weeks then ease. Hyperemesis gravidarum (severe vomiting causing dehydration) requires IV fluids — book to Mascot Healthcare immediately.
The nuchal translucency scan (11–14 weeks) is the most important first-trimester investigation — it screens for chromosomal abnormalities including Down syndrome (trisomy 21) by measuring fluid at the back of the baby's neck. Combined with blood tests (PAPP-A, beta hCG), it gives a precise risk assessment. This scan is also your best opportunity for a highly accurate gestational age dating.
Booking blood tests (can be done any time in the first trimester): Full blood count (anaemia is very common in Lagos women), blood group and Rhesus factor, HIV test, hepatitis B, syphilis (VDRL/TPHA), blood sugar (fasting) — baseline gestational diabetes screen, urine culture (asymptomatic bacteriuria causes preterm labour).
Second trimester (weeks 13–27)Nausea typically eases by week 13–14. Energy returns. The uterus is now large enough to be felt above the pubic symphysis. Fetal movements are felt by first-time mothers at approximately 18–20 weeks (experienced mothers from 16 weeks). The sex of the baby can usually be determined from week 16 onwards on scan.
The anomaly scan (detailed anatomy scan) at 18–22 weeks is the most comprehensive scan of the pregnancy. It systematically examines: brain, face, lips, heart (four chambers, great vessels), lungs, spine, abdomen, kidneys, bladder, limbs, and placental location. It takes 30–45 minutes and detects the majority of structural abnormalities. At Mascot Healthcare, the anomaly scan costs ₦15,000 and includes a detailed written report.
A fasting blood glucose (or glucose tolerance test) at 24–28 weeks screens for gestational diabetes — a complication affecting approximately 10–14% of Nigerian pregnancies. Untreated gestational diabetes causes fetal macrosomia (large baby), birth complications, and significantly elevated risk of type 2 diabetes in the mother later in life. Testing is simple and available same day at Mascot Healthcare.
Third trimester (weeks 28–40)Growth scans every 2–4 weeks for high-risk pregnancies (hypertension, diabetes, previous small baby, twins). All pregnancies benefit from a growth scan at 32 weeks — to assess fetal size, amniotic fluid level, and placental position. If the placenta was low-lying at the anomaly scan, a follow-up scan at 32–36 weeks confirms whether it has moved clear of the cervix.
A scan at 36–38 weeks confirms: baby's position (head-down for vaginal delivery vs breech), fetal weight estimate, amniotic fluid level, and placental grade. This scan determines whether a vaginal delivery is planned or whether early delivery or caesarean section is advisable. Reduced fetal movement at any point in the third trimester requires a same-day biophysical profile scan — do not wait.
All pregnancy scans from ₦7,000 at Mascot Healthcare, Akoka. By appointment, same-day report.