When Does Morning Sickness Start and How Long Does It Last?

Everything you need to know about pregnancy nausea - timeline, remedies, and when to seek help in Singapore.

What Causes Morning Sickness and When Does It Start?

Morning sickness is one of the most common pregnancy symptoms, affecting up to 80% of pregnant women. Despite the name, it can strike at any time of day or night. The main cause is the rapid rise of human chorionic gonadotropin (hCG) - the hormone produced after a fertilised egg implants in the uterus. Oestrogen levels also climb sharply in early pregnancy, which makes the digestive system slow down and increases sensitivity to smells.

Morning Sickness Timeline

Week What to Expect
Weeks 4-5 Mild queasiness may begin, often triggered by smells or an empty stomach
Weeks 5-6 Nausea typically starts for most women; some experience vomiting
Weeks 8-10 Peak severity - hCG levels are at their highest
Weeks 12-14 Most women find symptoms ease or disappear as hCG levels stabilise
After week 14 About 10% of women have nausea throughout the second trimester

Women carrying multiples or with a history of motion sickness tend to have more severe symptoms. If this is not your first pregnancy, your experience may differ from before - each pregnancy is different.

Evidence-Based Remedies for Morning Sickness

Not all remedies are created equal. Here is what the research actually says, ranked by the strength of evidence:

Remedy Evidence How to Use
Vitamin B6 (Pyridoxine) Strong 10-25mg three times daily; available over the counter at Guardian, Watsons
Ginger (tea, capsules, lozenges) Strong 250mg capsules 4x daily or fresh ginger tea; widely available in Singapore
Small frequent meals Strong Eat every 2 hours; never let stomach go empty
Sea-Bands (acupressure wrists) Moderate Available at Mothercare Singapore and online; safe, no side effects
Cold or room temperature foods Moderate Less smell than hot food; crackers, cold fruit work well
Lemon scent / peppermint Weak Inhaling lemon essential oil may help some women; low risk
Antihistamines (Doxylamine + B6) Strong Prescription only in Singapore; ask your gynae if symptoms are severe

Singapore tip: Many women find hawker food smells - especially sambal, frying oil, and fish paste - particularly triggering. Carry plain crackers, pack lunches in airtight containers, and use the air-conditioned food courts when possible during your first trimester.

Hyperemesis Gravidarum - When Morning Sickness Becomes Serious

About 1-2% of pregnant women develop hyperemesis gravidarum (HG) - severe, persistent nausea and vomiting that leads to dehydration, weight loss, and nutritional deficiencies. This is not regular morning sickness and requires medical treatment. If left untreated, HG can harm both mother and baby.

Normal Morning Sickness Hyperemesis Gravidarum (Go to A&E)
Nausea with occasional vomiting Vomiting more than 3-4 times per day
Can keep some food/fluids down Unable to keep any food or liquids down for 24 hours
Feels bad but can function Extreme weakness, unable to get out of bed
No significant weight loss Lost more than 5% of pre-pregnancy body weight
Normal urine output Dark urine or not urinating for 8+ hours (dehydration)
Improves by week 12-14 Dizziness, fainting, heart palpitations

Go to KKH Women's A&E or your nearest hospital A&E if you have any HG warning signs.

Treatment includes IV fluids for rehydration, anti-nausea medications (ondansetron, metoclopramide), and in severe cases, a short hospital admission. You will not be "being dramatic" - HG is a real medical condition.

Surviving Morning Sickness in Singapore's Climate

Singapore's heat and humidity can make nausea feel worse, especially during the morning commute or at outdoor markets. Here are practical strategies that work in the local context:

Food and Drink

  • - Plain congee (muay) or white rice are gentle on the stomach
  • - Ice cold 100 Plus or isotonic drinks help with hydration
  • - Watermelon and cold fruits are easy to keep down
  • - Avoid durian, strong curries, and fried foods in T1
  • - Keep plain biscuits (cream crackers) on your desk and bedside table

Daily Life

  • - Use MRT and buses early morning to avoid midday heat
  • - Request a seat on public transport - you can use the priority sticker from polyclinic
  • - Keep air-con at 24-25C at home; heat worsens nausea
  • - Inform HR early - most Singapore employers accommodate T1 flexibility
  • - Avoid peak hour crowds - smells from crowds can trigger nausea

TCM note: Some Singapore women use traditional Chinese medicine (TCM) for nausea relief. Acupuncture at the PC6 point has some research support. If you choose TCM, inform your gynae and ensure the practitioner knows you are pregnant, as some herbs are contraindicated in pregnancy.

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