🤰 Antenatal Guide — Weeks 13–26
Second Trimester Guide
The second trimester is typically the most comfortable period of pregnancy — morning sickness usually resolves, the miscarriage risk falls significantly after 12 weeks, and the bump becomes visible. It is also the time for the most important structural scan of the pregnancy.
Key Milestones
🌱 Weeks 13–16: Second trimester begins
The fetus is now fully formed with all organs in place — the remaining time is growth and maturation. Morning sickness typically resolves. Energy levels improve. The uterus rises above the pelvis and becomes visible.
🌱 Weeks 18–20: Baby's movements first felt
First-time mothers typically feel fetal movements (quickening) between 18–22 weeks. Women who have been pregnant before often feel movements from 16 weeks. Movements should become consistent and recognisable by 24 weeks.
🌱 Weeks 18–22: Anomaly scan window
The detailed anomaly scan examines all major fetal structures. This is the most important ultrasound of the pregnancy — see the dedicated anomaly scan guide for preparation details.
🌱 Week 24: Viability
At 24 weeks, a baby born extremely prematurely has a chance of survival with intensive neonatal care. This marks a significant psychological milestone. Preterm labour symptoms (regular tightening, pelvic pressure, pink discharge) from 24 weeks need immediate evaluation.
Essential Tests & Scans
Anomaly Scan (20-week scan)
⏱ Weeks 18–22
Systematic examination of baby's brain, face, spine, heart (4-chamber + outflow tracts), abdominal wall, kidneys, bladder, and all limbs. Placental location and amniotic fluid volume assessed. The single most important pregnancy ultrasound.
Gestational Diabetes Mellitus (GDM) Screen
⏱ Weeks 24–28
An oral glucose tolerance test (OGTT) with 75g glucose, blood drawn fasting and at 1 and 2 hours. GDM is more common in Nigerian women — particularly those with family history of diabetes, BMI over 30, or previous large baby. Undetected GDM significantly increases risks to mother and baby.
Full Blood Count (anaemia check)
⏱ Weeks 20–24
Iron requirement increases substantially in the second trimester as blood volume expands. Many Nigerian women are already iron-deficient before pregnancy. A mid-pregnancy FBC guides iron supplementation dosage — mild anaemia is managed with oral iron; severe anaemia may need IV iron or transfusion.
Cervical Length Scan (if previous preterm birth or symptoms)
⏱ Weeks 18–24 if indicated
A transvaginal measurement of cervical length. A short cervix (<25 mm before 24 weeks) indicates preterm birth risk and may prompt cervical cerclage or progesterone supplementation. Not routine — ordered by your obstetrician if indicated.
Urine protein and blood pressure checks (antenatal visits)
⏱ Every antenatal visit
At every antenatal visit, BP and urine are checked for early signs of pre-eclampsia, which becomes a risk from 20 weeks. Regular visits are essential — pre-eclampsia can develop rapidly and silently.
Frequently Asked Questions
What happens if my anomaly scan finds a problem?
Findings at anomaly scan range from minor variants (echogenic bowel, choroid plexus cysts — usually insignificant) to significant structural abnormalities. Many findings are uncertain until further evaluated by a fetal medicine specialist. You will be referred promptly and given clear information. The anomaly scan detects the majority of major structural problems when they are most treatable — either prenatally (some conditions are managed in the womb) or by planning delivery in a hospital with appropriate neonatal support.
Is it safe to travel during the second trimester?
The second trimester (14–28 weeks) is the safest and most comfortable time to travel during pregnancy. Most airlines permit travel up to 36 weeks for uncomplicated pregnancies. For long-haul flights: move every 1–2 hours to prevent DVT, wear compression stockings, stay hydrated. Avoid travel to malaria-endemic areas without prophylaxis — malaria in pregnancy is particularly dangerous.
What is gestational diabetes and how is it treated?
Gestational diabetes (GDM) is diabetes that develops during pregnancy due to placental hormones causing insulin resistance. It resolves after delivery in 90% of cases, but increases the risk of large baby, difficult delivery, neonatal hypoglycaemia, and recurrence in future pregnancies and as Type 2 diabetes later in life. Management: dietary modification (reduce refined carbs), blood glucose monitoring, and insulin if diet alone is insufficient. With proper management, outcomes for both mother and baby are excellent.
Can I have sex during pregnancy?
Yes, unless your obstetrician has advised against it. Sex during pregnancy is safe for most women. Reasons your doctor might advise abstaining: placenta praevia (low-lying placenta), unexplained bleeding, short cervix or cerclage in place, or rupture of membranes. Mild spotting after sex can occur due to increased cervical vascularity — this is normal, but mention it to your midwife.