What is a due date?
A due date (medically called the Estimated Due Date or EDD) is the date your baby is expected to be born, calculated as 280 days (40 weeks) from the first day of your last menstrual period (LMP). It's an estimate, not a deadline: a birth from 37 weeks 0 days to 41 weeks 6 days is early, full or late term (NICHD).
The due date is used by your healthcare provider to: (1) schedule prenatal appointments and screening tests at the right gestational ages, (2) monitor fetal growth (a baby measuring large or small for their age may signal complications), (3) plan for delivery, including what happens if you reach late term at 41 weeks, and (4) decide when interventions are appropriate (e.g., steroids for the baby's lungs if labor starts early).
Pregnancy is medically counted from LMP, not conception. So when you're told "you're 8 weeks pregnant," conception actually occurred ~6 weeks ago. The first 2 weeks of "pregnancy" technically happen before conception. The convention (Naegele's rule) is used because the LMP is far easier to remember than the day of conception.
How due dates are calculated
The standard medical formula is Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period. This assumes a 28-day cycle with ovulation on day 14 and conception on the same day. Pregnancy is medically counted from LMP, not conception, even though you're not actually pregnant during the first ~2 weeks.
Due Date = LMP + 280 days
Naegele's rule, the starting point of ACOG's Committee Opinion 700 on estimating the due date
NICHD counts births from 37 weeks 0 days to 38 weeks 6 days as early term, 39 weeks 0 days to 40 weeks 6 days as full term, and 41 weeks 0 days to 41 weeks 6 days as late term. Your due date is a target, not a deadline.
4 calculation methods compared
| Method | Formula | Accuracy |
|---|---|---|
| LMP (Naegele's) | LMP + 280 days | Assumes a 28-day cycle with ovulation on day 14 |
| Conception date | Conception + 266 days | Only as good as the conception date |
| Early ultrasound | Scan date − gestational age at scan + 280 days | Most accurate in the first trimester (ACOG) |
| IVF transfer | Day-3: +263 days; Day-5: +261 days | ACOG: date from embryo age and transfer date |
Worked examples for each method
Let's walk through how each method calculates a due date using the same starting point, let's say it's January 15, 2026 today and you want to know your due date.
Example 1, LMP method
Last period started December 1, 2025. EDD = Dec 1, 2025 + 280 days = September 7, 2026. You're currently 6 weeks 3 days pregnant.
Example 2, Conception date method
You know you conceived on December 18, 2025 (e.g., from ovulation tracking). EDD = Dec 18, 2025 + 266 days = September 10, 2026. Slight 3-day difference from the LMP method, because this conception date is 17 days after that LMP rather than the assumed 14.
Example 3, Ultrasound method
Today's scan (Jan 15, 2026) shows baby measures 8 weeks 2 days. Gestational age in days = 58. LMP-equivalent = Jan 15 - 58 days = November 18, 2025. EDD = LMP-equivalent + 280 = August 25, 2026. ACOG counts a first-trimester scan as the most accurate way to date a pregnancy, because it measures the embryo itself.
Example 4, IVF Day-5 transfer
You had a Day-5 blastocyst transfer on December 22, 2025. EDD = Transfer + 261 days = September 9, 2026, ACOG's rule for a day-5 embryo, since the fertilization date is known.
Notice how each method gives slightly different dates? This is normal, the methods make different assumptions about cycle length and ovulation timing. Your provider will pick the most reliable method for you (usually first-trimester ultrasound) and that becomes your "official" due date for the rest of pregnancy.
Trimesters and key milestones
First trimester · weeks 1–13
Major organ development. ACOG counts the first trimester up to 13 weeks 6 days. Chorionic villus sampling, if offered, at 10 to 13 weeks and the first trimester screen at 11 to 14 weeks (HHS Office on Women's Health). Common: morning sickness, fatigue, breast tenderness.
Second trimester · weeks 14–27
Often the most comfortable phase. Anatomy scan between 18 and 20 weeks (HHS Office on Women's Health), often when the sex can be seen. First "quickening" (baby's kicks) is usually felt in this trimester. Gestational diabetes test between 24 and 28 weeks (CDC). Belly visibly grows.
Third trimester · weeks 28–40
Rapid weight gain and growth. Tdap vaccine in weeks 27 through 36 and group B strep test in week 36 or 37 (CDC). Early term from 37 weeks and full term from 39 weeks (NICHD). Weekly checkups from week 36 to birth (HHS Office on Women's Health).
Complete week-by-week timeline
Weeks are counted from the first day of your last period. Each row comes from the dating rule or from the government or ACOG page named beside it; your provider's schedule may differ.
| Week | What happens | Source |
|---|---|---|
| 0 | First day of your last period: the date pregnancy is counted from. | Naegele's rule (ACOG) |
| 2 | Conception, in a 28-day cycle with ovulation on day 14. | Naegele's rule (ACOG) |
| 4 | Next period would be due, in a 28-day cycle. | Arithmetic |
| 4–28 | Prenatal visits about once a month. | HHS Office on Women's Health |
| 10–13 | Chorionic villus sampling (CVS), if offered. | HHS Office on Women's Health |
| 11–14 | First trimester screen. | HHS Office on Women's Health |
| 14 | Second trimester begins. | ACOG |
| 14–20 | Amniocentesis, if offered. | HHS Office on Women's Health |
| 18–20 | Anatomy ultrasound. | HHS Office on Women's Health |
| 20 | Halfway: 140 of 280 days. | Arithmetic |
| 24–28 | Gestational diabetes test. | CDC |
| 27–36 | Tdap vaccine, to protect the baby from whooping cough. | CDC |
| 28 | Third trimester begins. | ACOG |
| 28–36 | Prenatal visits twice a month. | HHS Office on Women's Health |
| 36–37 | Group B strep test; antibiotics during labor if positive. | CDC |
| 36 to birth | Weekly prenatal visits. | HHS Office on Women's Health |
| 37 | Early term (37 weeks 0 days to 38 weeks 6 days). | NICHD |
| 39 | Full term (39 weeks 0 days to 40 weeks 6 days). | NICHD |
| 40 | Estimated due date, 280 days after the LMP. | Naegele's rule (ACOG) |
| 41 | Late term (41 weeks 0 days to 41 weeks 6 days). | NICHD |
| 42 | Postterm. | NICHD |
Prenatal appointment schedule
Standard schedule for low-risk pregnancies (high-risk = more frequent):
- As soon as you think you're pregnant: First prenatal visit (NICHD). Bloodwork, urine, weight/BP baseline, often dating ultrasound.
- Weeks 11-14: First trimester screen, which includes a nuchal translucency scan, for chromosomal conditions.
- Once a month, weeks 4 to 28: Routine checkups, weight, BP, urine dip, fundal height, fetal heart tones.
- Weeks 18-20: Anatomy ultrasound, often when the sex can be seen.
- Weeks 24-28: Glucose test for gestational diabetes (CDC).
- Weeks 27-36: Tdap vaccine, to protect the baby from whooping cough (CDC).
- Twice a month, weeks 28 to 36: More frequent monitoring as third trimester progresses.
- Week 36 or 37: Group B strep swab (CDC). Discuss birth plan and labor signs.
- Weekly from 36 to birth: Cervical checks may begin. Watch for labor.
The visit frequency and test weeks are from the HHS Office on Women's Health's "Prenatal care and tests" page unless the CDC or NICHD is named. Many practices now offer telehealth for routine visits.
Tests and screenings during pregnancy
| Test | When | Purpose |
|---|---|---|
| Blood type / Rh | First visit | Determines whether you need Rh immune globulin (RhoGAM). |
| CBC + iron | First visit, and later if needed | Screen for anemia. |
| NIPT (cell-free DNA) | Ask your provider | Screens for Down syndrome and other trisomies. A screen, not a diagnosis. |
| First trimester screen (nuchal translucency) | 11-14 wks | Combined with bloodwork screens for chromosomal issues. |
| Anatomy ultrasound | 18-20 wks | Detailed scan of all organs + sex. |
| Glucose tolerance | 24-28 wks | Screens for gestational diabetes. |
| Tdap vaccine | 27-36 wks | Protects baby from whooping cough. |
| Group B strep | 36-37 wks | If positive, antibiotics during labor. |
Optional diagnostic tests (usually offered after an abnormal screen): CVS (10-13 wks), amniocentesis (14-20 wks). Both carry a small risk of miscarriage; ask your provider. Test weeks: HHS Office on Women's Health and CDC.
How accurate is your due date?
Due date estimates from LMP can be off if your cycle isn't 28 days or you're unsure when your last period started. ACOG's Committee Opinion 700 names an ultrasound in the first trimester (up to 13 weeks 6 days), measuring crown-rump length (CRL), as the most accurate way to set or confirm the due date.
The same opinion sets how large a gap between the ultrasound and LMP dates justifies changing the due date, and the allowed gap depends on how far along you were at the scan. It treats a pregnancy with no ultrasound confirming or changing the due date before 22 weeks as not optimally dated, and says later changes to the due date should be rare.
Reality check: The due date is 40 weeks after the LMP, but NICHD counts any birth from 37 weeks 0 days to 41 weeks 6 days as term (early, full or late), so a birth weeks before or after the date can be normal.
Nutrition and weight gain
Pregnancy nutrition isn't about "eating for two", it's about eating more of the right things. Caloric needs increase modestly: no extra calories in the first trimester, about +340 a day in the second, about +450 in the third (CDC). Total weight gain depends on pre-pregnancy BMI (CDC, from the Institute of Medicine):
| Pre-pregnancy BMI | Singleton gain | Twin gain |
|---|---|---|
| Underweight (<18.5) | 28-40 lbs | 50-62 lbs* |
| Normal (18.5-24.9) | 25-35 lbs | 37-54 lbs |
| Overweight (25.0-29.9) | 15-25 lbs | 31-50 lbs |
| Obese (30.0-39.9) | 11-20 lbs | 25-42 lbs |
*The CDC's figure; the Institute of Medicine set no twin range for underweight women.
Foods to emphasize: leafy greens (folate), salmon (DHA), eggs (choline), Greek yogurt (calcium + protein), legumes (iron), fortified whole grains, fruits, lean proteins.
Foods to avoid: raw fish/oysters/sushi (listeria), high-mercury fish (swordfish, king mackerel, shark, tilefish), unpasteurized cheese/milk, deli meats unless heated to steaming, raw or undercooked eggs/meat, raw sprouts, too much caffeine (ask your provider for a limit), all alcohol.
Use our BMI Calculator to find your pre-pregnancy BMI category and our TDEE Calculator to estimate maintenance calories before adding pregnancy adjustments.
Exercise during pregnancy
The CDC advises at least 150 minutes of moderate-intensity aerobic activity a week during pregnancy, for example 30 minutes on 5 days.
Safe activities: Walking, swimming, stationary cycling, low-impact aerobics, prenatal yoga or Pilates, light strength training. If you exercised regularly before pregnancy, you can usually continue at a moderate intensity.
Activities to avoid: Contact sports (soccer, basketball, hockey), high-fall-risk (skiing, horseback, gymnastics), scuba diving, hot yoga or hot Pilates, exercise in heat/humidity, activities that require lying flat on your back after the first trimester (CDC), heavy lifting that strains.
Stop and call doctor if: vaginal bleeding, dizziness, headache, chest pain, calf swelling, contractions, fluid leak, decreased fetal movement.
Always clear exercise plans with your provider, especially if you have placenta previa, cervical insufficiency, preeclampsia, severe anemia, or other complications.
Warning signs, call your provider
Call your OB or midwife (or go to the ER if severe) for any of these. Most are on the CDC's list of urgent maternal warning signs (Hear Her campaign); the preterm contraction sign is NICHD's.
- Vaginal bleeding, at any point in pregnancy.
- Severe abdominal pain, especially if persistent or one-sided.
- Severe headache + vision changes (blurred, spots), possible preeclampsia.
- Sudden swelling of face/hands + headache, possible preeclampsia.
- Baby's movements stopping or slowing. The CDC says no set number of movements is normal; a change is what matters.
- Fluid leaking from vagina, possibly broken water (PROM).
- Contractions before 37 weeks, every 10 minutes or more often.
- Severe nausea/vomiting + can't keep liquids down, possible hyperemesis.
- Fever of 100.4°F (38°C) or higher, possible infection.
- Painful urination + back pain, possible kidney infection.
- Signs of DVT, calf pain, swelling, redness in one leg.
- Fall, car accident, or trauma, get checked even if you feel fine.
When in doubt, call. Many OB offices have an after-hours line. Better to call and be reassured than to wait.
Preparing for labor
Start preparing early in the third trimester. Early term begins at 37 weeks (NICHD), so aim to be ready before then:
- Take childbirth classes (in-person or online). Most hospitals offer them free.
- Tour your hospital or birth center, know where to park, where to go.
- Pack a hospital bag a few weeks before your due date; labor can start any time.
- Choose a pediatrician for the baby's first checkups after you go home.
- Install the car seat before your due date; many fire stations will check it for free.
- Discuss birth preferences with your provider (epidural, doula, episiotomy preferences, immediate skin-to-skin, delayed cord clamping).
- Set up baby essentials: crib/bassinet, safe sleep area, diapers (NB + size 1), wipes, a few outfits.
- Stock the freezer, pre-make meals; you'll be too tired to cook in the first weeks.
- Plan FMLA / parental leave with HR well ahead. Submit paperwork early.
- Add baby to insurance soon after birth; each plan sets its own deadline, so check yours.
Signs of labor: contractions that come regularly and get longer, stronger and closer together, bloody show (mucus plug), water breaking (gush or trickle of fluid), persistent low backache. Ask your provider when they want you to call or come in.
If your due date passes
Going past the due date is common. NICHD calls 41 weeks 0 days to 41 weeks 6 days "late term" and 42 weeks 0 days onward "postterm".
What to expect: As you approach or pass 41 weeks, your provider will talk with you about extra monitoring and about inducing labor, and when. Discuss timing with your provider.
Encouraging labor: your provider may offer a membrane sweep. Home methods you'll read about online (walking, spicy food, castor oil and others) have little evidence behind them, and some have side effects; ask before trying any.
Medical induction methods: cervical ripening with prostaglandins (Cervidil, Cytotec), Foley balloon, IV oxytocin (Pitocin), artificial rupture of membranes (AROM/amniotomy). An induction can take many hours, especially if the cervix needs ripening first.
Twins and multiples
About 3% of US births are twins (30.1 per 1,000 live births in 2024, CDC). The "due date" still uses the 40-week LMP calculation, but twins and triplets are born earlier on average. The CDC's published average length of pregnancy at birth, by plurality, from 2005 data:
- Single babies: 38.7 weeks.
- Twins: 35.2 weeks.
- Triplets: 31.9 weeks.
- Quadruplets: 29.8 weeks.
Twin pregnancies usually mean more frequent prenatal visits and ultrasounds, higher nutritional needs (see the twin weight-gain ranges above), and a higher chance of preterm labor, gestational diabetes, preeclampsia, and C-section. Your provider will plan the timing and way of delivery with you. Use our calculator with the LMP method; the EDD is the same target, but plan for an earlier birth.
Types of twins: Dichorionic-Diamniotic (di/di), separate placentas, separate sacs. Monochorionic-Diamniotic (mo/di), shared placenta, separate sacs (TTTS risk). Monochorionic-Monoamniotic (mo/mo), shared everything (highest risk, with close monitoring).
Common pregnancy myths debunked
- "You're eating for two." No. The CDC's figures are no extra calories in the first trimester, about 340 extra a day in the second and about 450 in the third.
- "You can predict baby's sex from belly shape." False. Position depends on baby's posture, your build, and how many pregnancies you've had, not sex.
- "Spicy food induces labor." No reliable evidence. May give you heartburn.
- "You shouldn't lift your arms above your head." Total myth, won't wrap the cord.
- "Bath water can drown the baby." No, the cervix is sealed shut by the mucus plug. Ask your provider about very hot baths and hot tubs, though.
- "Sex during pregnancy is dangerous." Generally safe unless you have placenta previa, cervical issues, or your provider says otherwise.
Pregnancy glossary
- EDD (Estimated Due Date)
- The 40-week mark from LMP, your "due date."
- LMP (Last Menstrual Period)
- First day of your last period, the standard starting point for pregnancy dating.
- Gestational age
- Weeks since LMP. The "you're X weeks pregnant" number.
- CRL (Crown-Rump Length)
- Embryo measurement on first-trimester ultrasound, the most accurate way to date a pregnancy (ACOG).
- NIPT
- Non-Invasive Prenatal Testing, a cell-free DNA blood test that screens for chromosomal conditions. A screen, not a diagnosis.
- Quickening
- The first time you feel the baby move, usually in the second trimester (sometimes earlier in later pregnancies).
- Trimester
- Pregnancy is divided into three phases, 1st (weeks 1-13, to 13 weeks 6 days), 2nd (14-27), 3rd (28-40), as ACOG counts them.
- Full term
- 39 weeks 0 days to 40 weeks 6 days (NICHD). Early term is 37 weeks 0 days to 38 weeks 6 days; late term 41 weeks 0 days to 41 weeks 6 days.
- Preterm
- Born before 37 weeks (CDC). It affected about 1 in every 10 US babies in 2022.
- Postterm
- 42 weeks 0 days and beyond (NICHD).
- Naegele's rule
- Add 280 days to the LMP. The starting point of ACOG's due-date guidance.
- PROM
- Premature Rupture Of Membranes, water breaks before labor starts.
- PPROM
- Preterm PROM, water breaks before 37 weeks. Call your provider right away.
Frequently asked questions
How is my due date calculated?
From your last period: 280 days on from its first day (Naegele's rule). From a known conception date: 266 days on. From an early ultrasound: the age measured at the scan, carried forward. ACOG treats a first-trimester scan as the best of the three.
How accurate is my due date?
It is an estimate, not a forecast of the birth day. A date from your last period assumes a regular 28-day cycle, and ACOG prefers an early ultrasound when there is one. Any birth from week 37 through week 41 counts as term (NICHD), so a baby born a week or two either side of the date is on time.
What's the difference between LMP and conception date?
LMP (Last Menstrual Period) is the first day of your last period, easier to remember and the standard medical reference point. Conception is when sperm meets egg, which the standard calculation puts 14 days after the LMP in a 28-day cycle. Pregnancy is measured from the LMP, so when your doctor says you're '8 weeks pregnant,' conception was about 6 weeks ago.
What if I had IVF?
ACOG says to date a pregnancy from assisted reproduction by the embryo's age and the transfer date. For a Day-3 embryo transfer, your due date is the transfer date + 263 days. For a Day-5 (blastocyst) transfer, it's the transfer date + 261 days. The calculator handles both: select 'IVF transfer date' and choose Day 3 or Day 5.
What are the trimesters?
ACOG's dating guidance counts the first trimester up to 13 weeks 6 days. First trimester: weeks 1–13 (organ development; nausea is common). Second trimester: weeks 14–27 (anatomy ultrasound, usually between 18 and 20 weeks per the HHS Office on Women's Health, and the gestational diabetes test, usually between 24 and 28 weeks per the CDC). Third trimester: weeks 28–40 (weight gain, group B strep test, delivery preparation).
What does 'full term' mean?
Full term is 39 weeks 0 days to 40 weeks 6 days. NICHD's categories: early term (37 0/7 to 38 6/7 weeks), full term (39 0/7 to 40 6/7 weeks), late term (41 0/7 to 41 6/7 weeks) and postterm (42 0/7 weeks and beyond). NICHD says babies do best when they are born during weeks 39 and 40. Babies born before 37 weeks are 'preterm' and may need NICU care depending on how early.
When should I have my first prenatal appointment?
NICHD advises anyone who thinks they may be pregnant to schedule a visit with a health care provider to begin prenatal care. The first visit usually includes blood work, a urine test, weight and blood pressure, your medical history, and often an ultrasound to confirm dates. After that, the HHS Office on Women's Health gives a typical schedule of once a month for weeks 4 through 28, twice a month for weeks 28 through 36, and weekly from week 36 to birth.
Can I tell the baby's sex from the due date calculator?
No, sex is determined at conception by the sperm's chromosome (XX or XY) and isn't related to the due date. Tests that can show it include a cell-free DNA blood screen, chorionic villus sampling (CVS, 10 to 13 weeks), amniocentesis (14 to 20 weeks) and the anatomy ultrasound (18 to 20 weeks); the week ranges are the HHS Office on Women's Health's. CVS and amniocentesis are diagnostic tests with their own risks, offered for medical reasons rather than to learn the sex.
How is my pregnancy week counted?
Pregnancy is counted in weeks from the first day of your last menstrual period (LMP). At 4 weeks, your next period would be due in a 28-day cycle. At 14 weeks, the second trimester begins. At 20 weeks, you're halfway (140 of 280 days). At 28 weeks, the third trimester begins. At 37 weeks, early term; at 39 weeks, full term (NICHD). At 40 weeks, the due date. Each week is divided into days (e.g., '14 weeks 3 days').
What if my cycle isn't 28 days?
The standard LMP-based calculation assumes a 28-day cycle with ovulation on day 14. If your cycle is longer, you probably ovulated later. A common adjustment, which is an illustration and not an ACOG rule, moves the due date by the difference: a 32-day cycle gives a date 4 days later. This calculator doesn't make that adjustment. A first-trimester ultrasound gives a more accurate date, and your provider may change your due date if the ultrasound and LMP dates differ by more than ACOG's limit for that stage of pregnancy.
What are the key milestones to know?
Week 14: second trimester begins (ACOG). Weeks 18–20: anatomy ultrasound (HHS Office on Women's Health). Weeks 24–28: gestational diabetes test (CDC). Weeks 27–36: Tdap vaccine (CDC). Week 28: third trimester. Weeks 36–37: group B strep test (CDC). Week 37: early term. Week 39: full term (NICHD). Week 40: due date. Week 41: late term. Week 42: postterm.
Is this calculator a substitute for medical care?
No, this calculator gives an estimate based on dates only. Your healthcare provider may adjust your due date based on ultrasound measurements, fundal height, or other clinical findings. Always confirm dates with your OB or midwife. This tool doesn't replace prenatal care, screening, or any medical advice.
What's the difference between gestational age and fetal age?
Gestational age is counted from the first day of LMP (the medical standard) and includes the ~2 weeks before conception. Fetal (or embryonic) age is counted from the day of conception, so it's about 2 weeks SHORTER. When your doctor says 'you're 12 weeks pregnant,' the embryo is about 10 weeks old. Milestones, ultrasound dating and due dates use gestational age. Pregnancy apps usually display gestational age too.
What if I conceived through frozen embryo transfer (FET)?
Frozen embryo transfers (FET) calculate due date the same as fresh IVF: due date = transfer date + 263 days (Day-3 embryo) or + 261 days (Day-5 blastocyst). The freezing and thawing time doesn't count; ACOG dates the pregnancy by the embryo's age and the transfer date. The same rule gives + 260 days for a Day-6 embryo, but ask your clinic for the date they have recorded.
Can I take a pregnancy test based on this calculator?
The calculator estimates a due date, not when to test. Home pregnancy tests detect the hormone hCG; follow the test's instructions on when to take it, and ask your provider to confirm the result. In a 28-day cycle your next period would be due at 4 weeks of gestational age, 2 weeks after conception.
What is the 'rule of nines' or '9-month' calculation?
Pregnancy is commonly described as 9 months but is actually 40 weeks: 280 days is about 9.2 calendar months, while 9 average months is about 274 days. 'Month' counting is informal; the medical standard is weeks. From LMP: month 1 = weeks 1–4, month 2 = weeks 5–8, etc. This is why moving from 'month' to 'week' can feel confusing; they don't line up cleanly.
When can I find out the baby's sex?
Options include: (1) a cell-free DNA blood screen, which your provider may offer as a screen for chromosome conditions. (2) The anatomy ultrasound, usually between 18 and 20 weeks. (3) Chorionic villus sampling (CVS), 10 to 13 weeks, an invasive diagnostic test. (4) Amniocentesis, 14 to 20 weeks, also invasive and diagnostic. The week ranges are the HHS Office on Women's Health's. CVS and amniocentesis are done for medical reasons, not to learn the sex.
What if my due date passes without labor starting?
Many pregnancies go past the due date. NICHD counts week 41 as late term and week 42 onward as postterm, so plan with your OB or midwife before the date arrives: extra monitoring, a membrane sweep and induction are the usual options.
How long is each trimester in months?
First trimester: weeks 1-13 (98 days, about 3.2 months). Second trimester: weeks 14-27 (98 days, about 3.2 months). Third trimester: week 28 to the due date at 40 weeks (84 days, about 2.8 months). Total: 280 days, about 9.2 calendar months. The trimesters aren't equal because pregnancy is measured in weeks, not months. Early term starts at 37 weeks and full term at 39 weeks (NICHD).
What prenatal vitamins should I take?
The CDC advises everyone who could become pregnant to get 400 micrograms (mcg) of folic acid every day, because neural tube defects happen in the first few weeks of pregnancy, often before you know you are pregnant. A prenatal vitamin also usually contains iron, calcium, vitamin D, iodine and sometimes DHA. Ask your provider which one suits you; some people need extra iron, vitamin D, or B12.
When does morning sickness start and end?
MedlinePlus (National Library of Medicine) says morning sickness most often begins during the first month of pregnancy and continues through the 14th to 16th week. Despite the name, it can occur any time of day. Most pregnant women have at least some nausea, and about one third have vomiting. Small, frequent meals can help; your provider can suggest treatments. Get care promptly for severe vomiting, if you can't keep liquids down, or if you're losing weight.
Can I exercise during pregnancy?
Yes, for most pregnancies. The CDC's guide is 150 minutes of moderate activity a week, such as walking or swimming. Skip exercises done on your back after the first trimester, contact sports, anything with a high risk of falls, scuba diving and hot yoga. Ask your provider first if you have complications.
What weight gain is normal in pregnancy?
The CDC's table, from the Institute of Medicine, by pre-pregnancy BMI: Underweight (BMI under 18.5): gain 28-40 lbs. Normal weight (18.5-24.9): gain 25-35 lbs. Overweight (25.0-29.9): gain 15-25 lbs. Obese (30.0-39.9): gain 11-20 lbs. For twins: normal weight 37-54 lbs, overweight 31-50 lbs, obese 25-42 lbs, and underweight 50-62 lbs (a CDC figure; the Institute of Medicine set none). Use our BMI Calculator to find your pre-pregnancy category.
What is preterm labor and how do I recognize it?
Preterm labor is labor that starts before 37 weeks; NICHD describes it as happening from 20 weeks through 36 weeks. Warning signs NICHD lists: contractions every 10 minutes or more often, a change in vaginal discharge (leaking fluid or bleeding), pressure in the pelvis, a low dull backache, cramps like a period, and abdominal cramps with or without diarrhea. Call your provider IMMEDIATELY if any occur before 37 weeks. Treatment depends on how far along you are and may include medicines to delay labor or steroids for the baby's lungs.