Jen 4% dětí se rodí v termínu porodu — výpočet ACOG na 280 dní

Odkud číslo 280 dní opravdu pochází

Franz Karl Naegele was a German obstetrician working in Heidelberg in the 1830s. In an 1838 textbook he proposed a simple formula: take the first day of the last menstrual period, add a year, subtract three months, then add seven days. That gives you a date roughly 280 days later — and it is still the math behind every due date you have ever been told. Two centuries later, the World Health Organization and the American College of Obstetricians and Gynecologists (ACOG Committee Opinion 700) still use that number as the baseline. The assumptions baked into it are old: a 28-day cycle, ovulation on day 14, conception on the day of ovulation, and an embryo that develops at exactly average pace. For most people one of those is wrong.

Proč se tak málo dětí rodí v termínu

Jukic and colleagues (Human Reproduction, 2013) tracked 125 healthy pregnancies day-by-day, from a confirmed ovulation through to delivery. The variation between women — even excluding all known abnormalities — was 37 days. Only about 4-5% of babies actually arrive on the predicted due date. Roughly 60% arrive in the week before or the week after, and the remaining ~35% sit further out on either side. Inside the 37 to 42 week window the baby is still considered term. The due date is a peak, not a deadline. Knowing that changes the whole emotional curve of week 39, 40 and 41 — when most people think something has gone wrong but in fact almost nothing has.

PM nebo ultrazvuk: které datum vítězí

If you are sure of the first day of your last menstrual period and your cycle is regular at 28 days, Naegele’s rule is acceptable. Anyone whose period is irregular, who was on hormonal contraception within three months, or who cannot remember the exact date — the rule starts to drift. Ultrasound crown-rump length (CRL) measured between 8 and 13 weeks is accurate within 5-7 days. ACOG Committee Opinion 700 (2017) is explicit: when LMP and ultrasound disagree by more than 7 days in the first trimester, use the ultrasound date. After 22 weeks ultrasound dating becomes less reliable because babies grow at different rates. Your maternity record will list the EDD — that is the figure your hospital actually uses.

→ Kalkulačka termínu porodu (Naegele)

Co „v termínu”, „po termínu” a „předčasný” doopravdy znamenají

ACOG and WHO classify the timing in five bands, not two. Pre-term is birth before week 37 (further split into very pre-term <32 weeks and extremely pre-term <28). Early term is week 37 to 38+6. Full term is 39 to 40+6 — the lowest-risk window for the baby. Late term is 41 to 41+6. Post-term is from week 42 onward, and most maternity units will discuss induction by then because stillbirth risk rises after week 41. “Going overdue” by a few days is normal; going past 42 is when conversation becomes urgent. None of these labels mean something is wrong with you. They are calendar buckets, not verdicts.

Co dalšího sledovat v těhotenství

Two other numbers carry similar weight during pregnancy and after. Nausea: the PUQE-24 score (Koren 2002, endorsed by ACOG 189) separates typical morning sickness from hyperemesis gravidarum that needs medical care — same-day, not next appointment. Mood: the EPDS (Cox 1987) is the ten-question screener every postnatal visit should include; a score of 10 or more is the threshold to talk to your GP. Both are linked below. The due-date calculator at the bottom uses Naegele plus an optional ultrasound override — the same logic your obstetrician is using.

→ PUQE test těhotenské nevolnosti · EPDS test poporodní deprese

Při silném krvácení, prudké bolesti břicha, náhlé silné bolesti hlavy, rozmazaném vidění nebo chybějících pohybech plodu po 24. týdnu — kontaktujte porodnici tentýž den, nečekejte na další termín.

Související kalkulačky

• Kalkulačka termínu porodu (Naegele)
• PUQE test těhotenské nevolnosti
• EPDS test poporodní deprese
• Kalkulačka BMI
• Kalkulačka spánkových cyklů