A Single pregnancy can feel wonderfully straightforward on paper—one baby, one placenta, one due date. And yet, real life rarely stays that tidy. Maybe your first scan brought relief (“Only one heartbeat—okay, we can breathe”). Or maybe it raised fresh questions: How often will I need visits? What tests are truly needed? When should I worry about movements, bleeding, blood pressure?

A Single pregnancy usually comes with a lighter monitoring schedule than twins, but the essentials remain the same: confirm dating, track your health, follow the baby’s growth, and plan birth with flexibility.

Single pregnancy: what to expect week by week

What “Single pregnancy” means (one baby) and common terms

A Single pregnancy (also called a singleton gestation) means one fetus is developing in the uterus. Pregnancy is counted in weeks of gestation from the first day of the last menstrual period (LMP), not from conception.

Trimester language is standard:

• First trimester: weeks 1–12
• Second trimester: weeks 13–26
• Third trimester: weeks 27–40

And “term” has precise medical categories that often guide induction discussions:

• Early term: 37+0 to 38+6 weeks
• Full term: 39+0 to 40+6 weeks
• Late term: 41+0 to 41+6 weeks
• Post-term: 42+0 weeks and beyond

Single vs multiple pregnancy: what changes

Compared with twins or triplets, a Single pregnancy generally means:

• fewer ultrasounds (unless a risk factor appears)
• lower chance of spontaneous birth before 37 weeks
• simpler birth planning (though not always unpredictable)

With multiple pregnancy, nausea and fatigue can feel stronger (higher hormone levels), and follow-up is usually tighter—more visits, more growth scans, and earlier delivery planning.

Key milestones by trimester and what “term” means

If you like anchoring points, here’s a practical timeline:

• Weeks 5–6: early ultrasound may confirm the pregnancy is in the uterus, heartbeat may be seen around 6 weeks via transvaginal scan.
• Weeks 7–12: rapid organ formation, the placenta gradually takes over hormone production.
• Weeks 11–14: NT scan may be offered as part of first-trimester screening.
• Weeks 18–22: anatomy scan (organs, placenta, fluid, growth).
• Weeks 24–28: screening for gestational diabetes.
• Weeks 37–40: the term window—labour can start any day.

Confirming a Single pregnancy and dating the due date

Home pregnancy tests and the first medical confirmation

Urine pregnancy tests detect hCG. A negative test can simply mean it was taken early or after drinking lots of fluids. First-morning urine often gives a clearer result.

At your first visit, the clinician usually reviews:

• LMP and cycle regularity
• symptoms (pain, bleeding, nausea)
• medication use

In selected situations (pain, bleeding, uncertain dates), blood hCG may be repeated to help guide next steps.

Dating ultrasound (gestational sac, fetal pole, crown–rump length)

Ultrasound confirms the number of embryos and provides the most reliable early dating:

• gestational sac and yolk sac appear first
• fetal pole follows
• CRL (crown–rump length) between about 7–13 weeks is the most accurate dating measure

It’s normal if the ultrasound due date shifts by a few days compared with LMP—especially with irregular cycles.

Confirming viability (fetal heartbeat)

A heartbeat is often seen around 6 weeks on transvaginal ultrasound, but sometimes a bit later. If a heartbeat is not seen when expected, many teams repeat ultrasound in 1–2 weeks rather than drawing conclusions from a single scan.

Ectopic vs intrauterine pregnancy: the early safety check

Early pregnancy care focuses first on location. A transvaginal ultrasound is the main test.

Seek urgent care for heavy bleeding, severe one-sided pain, shoulder-tip pain, dizziness, or fainting—these can be warning signs of ectopic pregnancy complications.

Your pregnancy basics: placenta, fluid and umbilical cord

Placenta development and placenta location

The placenta forms from chorionic villi attaching to the uterine lining and becomes the exchange organ: oxygen and nutrients in, waste out.

Placenta location may be anterior, posterior, fundal, or lateral. A low-lying placenta mid-pregnancy often moves away from the cervix as the uterus grows.

Two situations change follow-up and delivery planning:

• Placenta previa (placenta covering/near cervix): risk of painless bleeding later, repeat scans and sometimes planned caesarean.
• Placenta accreta spectrum (abnormal attachment): more likely after prior uterine surgery, including C-section.

Amniotic fluid: what “low” and “high” can mean

Amniotic fluid is measured by ultrasound using:

• AFI (amniotic fluid index), often normal around 5–25 cm
• SDP (single deepest pocket), often normal around 2–8 cm

Low fluid (oligohydramnios) may occur with ruptured membranes, post-term pregnancy, or placental underperformance, and can increase cord compression risk.

High fluid (polyhydramnios) may be associated with diabetes or fetal conditions, it can increase preterm labour risk and malpresentation.

Umbilical cord: insertion patterns that matter

Most cords insert centrally or slightly off-centre. Two insertions get closer attention:

• marginal insertion
• velamentous insertion

If vessels cross the cervix (vasa previa), delivery planning becomes highly specific, because bleeding risk can be severe.

Prenatal care schedule in a Single pregnancy

What happens at the first prenatal visit

The first visit usually includes:

• history and risk assessment
• blood pressure, weight, BMI
• labs: CBC, blood group/Rh, antibody screen, infection screening (HIV, hepatitis B, syphilis), urine testing
• discussion of screening options and ultrasound timing

Typical visit frequency (and when it increases)

For an uncomplicated Single pregnancy, a common schedule is:

• up to 28 weeks: every 4 weeks
• 28–36 weeks: every 2 weeks
• from 36 weeks: weekly

Visit frequency increases with hypertension, diabetes, placenta issues, growth concerns, reduced movements, or a history of complications.

Routine checks at visits

Often included:

• blood pressure
• weight trend
• urine dipstick in many clinics
• fetal heart rate by Doppler from around 9–12 weeks

Fundal height and when ultrasound is added

Fundal height measurement usually begins around 18–20 weeks. If it’s smaller or larger than expected—or if you have risk factors—an ultrasound may be advised to check growth and fluid.

Screening and testing by trimester

First trimester: NT, combined screening, NIPT

Depending on your setting and preferences:

• NT scan (11–14 weeks)
• combined screening
• NIPT (cell-free DNA) from about 9–10 weeks

Screening estimates risk, it does not confirm diagnosis.

Second trimester: anatomy scan and serum screening

• anatomy scan at 18–22 weeks
• quad screen/AFP where offered

Third trimester: diabetes and repeat labs

Commonly:

• gestational diabetes screening at 24–28 weeks
• repeat CBC for anaemia

When diagnostic tests may be offered (CVS, amniocentesis)

If screening is high-risk or there is a known concern:

• CVS (10–13 weeks)
• amniocentesis (15–20 weeks)

Ultrasounds during a Single pregnancy

Routine ultrasound timing

Many parents have:

• a dating/viability scan in the first trimester
• an anatomy scan at 18–22 weeks

When growth scans are recommended

Growth scans may be added if:

• fundal height raises concern
• there is hypertension, diabetes, obesity, smoking exposure, or prior growth issues
• there is suspected large baby (macrosomia) or fetal growth restriction

Measurements include head, abdomen, femur length, Doppler may be added when placental blood flow is questioned.

Nutrition, supplements and weight gain

Everyday nutrition foundations

For many Indian households, meals are a mix of grains, dals, vegetables, curd, eggs/fish/meat, and seasonal fruits. The goal is variety and regularity, not perfection.

Helpful basics:

• protein at most meals (dal, paneer, eggs, fish/chicken, soy)
• fibre to reduce constipation
• hydration

Common supplements

Many prenatal regimens include folic acid, iron, iodine, calcium and vitamin D. Avoid stacking multiple supplements without medical advice.

Healthy weight gain ranges by pre-pregnancy BMI

Common singleton ranges:

• BMI <18.5: 12.5–18 kg
• BMI 18.5–24.9: 11.5–16 kg
• BMI 25–29.9: 7–11.5 kg
• BMI ≥30: 5–9 kg

Food safety

• avoid unpasteurised dairy
• cook meats and eggs well
• wash fruits/vegetables thoroughly

Lifestyle: exercise, work, travel and sleep

Safe activity for most uncomplicated pregnancies

Aim for about 150 minutes/week of moderate activity if your clinician agrees: walking, swimming, prenatal yoga.

Stop and seek advice for bleeding, leaking fluid, chest pain, dizziness, or regular painful contractions.

Work and household load

If prolonged standing, heat, or heavy lifting worsen symptoms, ask for adjustments—extra breaks, hydration, sitting time.

Sleep and comfort

Left-side sleeping often improves blood flow. Pillows between knees can reduce hip and back strain.

Substances

Avoid alcohol, smoking/vaping, and drugs. Keep caffeine modest.

Who may need closer monitoring

Extra monitoring may be added with age 35+, underweight or obesity, hypertension, diabetes, kidney or thyroid disease, prior preterm birth, or IVF conception.

Common complications in a Single pregnancy

Hyperemesis, anaemia, UTIs

Severe vomiting (hyperemesis gravidarum) may need antiemetics or IV fluids.

Iron deficiency anaemia is common and treatable—ask if your Hb and ferritin are being followed.

UTIs should be treated promptly.

Hypertensive disorders

Gestational hypertension and preeclampsia often appear after 20 weeks. Warning symptoms include severe headache, vision changes, right upper abdominal pain, and sudden swelling.

Preterm labour and rupture of membranes

Regular contractions before 37 weeks or water leakage needs prompt assessment.

Monitoring baby’s well-being

Fetal movements and kick counts

From around 28 weeks, track movements. A clear drop from your baby’s usual pattern is a reason to call.

NST and BPP

• NST checks fetal heart rate reactivity.
• BPP combines ultrasound movements, tone, breathing practice, and fluid.

When to call or seek care

Call urgently for heavy bleeding, leaking fluid, severe headache or vision changes, right upper abdominal pain, reduced fetal movements, fever, or persistent vomiting with dehydration.

Birth planning and delivery options

Timing in uncomplicated Single pregnancy

Many uncomplicated singleton pregnancies deliver between 39–41 weeks. If pregnancy crosses due date, clinicians may add monitoring and discuss induction.

Pain relief options

Epidural is highly effective. Non-medication support—movement, breathing, warm water—can help too.

Postpartum after a Single pregnancy

Early recovery and warning signs

Seek urgent care for heavy bleeding, fever, foul-smelling discharge, chest pain, breathlessness, or a swollen painful leg.

Feeding and emotional health

Breastfeeding often benefits from hands-on help early. Baby blues often settle in 1–2 weeks, persistent low mood or anxiety deserves prompt support.

Key takeaways

• Single pregnancy means one baby, monitoring is often lighter than twins, but regular checks still matter.
• First-trimester dating with CRL gives the most accurate due date.
• Screening is trimester-based, with diagnostic tests available when needed.
• Know red flags: heavy bleeding, leaking fluid, preeclampsia symptoms, fever, persistent vomiting, or reduced movements.
• Parents can download the Heloa app for personalised guidance and free child health questionnaires.

Questions Parents Ask

Is a “single pregnancy” ever mistaken for twins (or the other way around)?

Yes, especially very early on. In the first weeks, an ultrasound might be too soon to clearly see the number of embryos, or one embryo may stop developing early (sometimes called a “vanishing twin”). If you were initially told “maybe two” and later it’s “one,” it can feel confusing—or emotional. A repeat scan a little later often brings clarity and reassurance.

Do singleton pregnancy symptoms feel different from twin pregnancy symptoms?

Often, yes—but there’s a big overlap. With twins, nausea, fatigue, and faster belly growth can be more noticeable because hormone levels may be higher. Still, a single pregnancy can also come with strong symptoms, and mild symptoms can happen with twins. If symptoms suddenly become severe (for example, vomiting you can’t control), it’s always reasonable to reach out for support.

What are early signs in the first trimester that deserve medical advice?

Many first-trimester sensations are normal (cramps, spotting, nausea). It’s worth calling your care team promptly for heavy bleeding, one-sided intense pain, dizziness/fainting, fever, or pain with shoulder-tip discomfort. These signs don’t automatically mean something is wrong, but getting checked early can make a real difference.