Blog
Practical, evidence-based reading on pregnancy, postpartum, and the science behind ProbaBaby's predictions.
Baby Zodiac Signs by Due Date: What Sign Will Your Baby Be?
Your due date lands your baby in one of 12 zodiac signs — until it moves. Here are the exact date ranges our calculator uses, the cusp windows where two signs are still in play, and why an estimated date can change the answer.
BMI Before Pregnancy: Why It Matters and What It Changes
Your pre-pregnancy BMI is the input that sets your recommended weight gain, and it follows you through the whole pregnancy. Here's how the BMI bands map to the IOM targets, and where a single height-and-weight number stops being useful.
Braxton Hicks vs Real Contractions: How to Tell the Difference
Braxton Hicks tighten and let go without ever finding a rhythm. Real contractions get longer, stronger and closer together, and they ignore whatever you do to stop them. Here is the side-by-side, the practical test, and when to call regardless of what your timer says.
Caffeine During Pregnancy: How Much Is Safe? (The 200 mg Rule)
Almost every guideline lands on the same ceiling: under 200 mg of caffeine a day in pregnancy. Here's what that is in real mugs, cans and squares of chocolate — and how strong the evidence behind the number really is.
Cluster Feeding: What It Is, When It Happens and How to Survive It
Cluster feeding is a newborn feeding again and again for hours, usually in the evening. Here is what the NHS, CDC and AAP actually say about it, the coping strategies that hold up, and the specific signs that point to poor milk transfer instead.
Di/Di, Mo/Di and Mo/Mo Twins: What Chorionicity Means for Your Pregnancy
Di/di twins have two placentas and two sacs, mo/di share a placenta, mo/mo share both. Here is how the 11-14 week scan tells them apart with the lambda and T sign, what changes in your scan schedule, and how each type shifts the week your babies are likely to arrive.
Hospital Bag Checklist: What to Pack for Labor (2026 Guide)
Most "what to pack" lists are someone else's bag. Here's the framework for building yours: three bags (you, your partner, baby), tuned to your delivery type, with the items hospitals don't tell you about until you're already there.
How Baby Eye Color Is Inherited: OCA2, HERC2 and Why Two Brown-Eyed Parents Can Have a Blue-Eyed Baby
The one-gene eye colour chart from school biology is wrong. Two genes on chromosome 15 do most of the work, dozens more fine-tune it, and that is exactly why two brown-eyed parents can have a blue-eyed baby.
How Many Wet Diapers Should a Newborn Have? (Daily Norms by Day)
A newborn's diaper count climbs day by day: one wet diaper on day one, and at least six by the end of the first week. Here's the day-by-day chart, plus the stool colours and dehydration signs worth a phone call.
How Much Water Do You Need During Pregnancy?
ACOG says 8 to 12 cups a day, and the IOM sets an adequate intake of 3.0 L of total water for pregnancy. Here is where those numbers come from, and why your body weight, your activity and the weather matter more than your trimester.
How ProbaBaby Calculates Prediction Confidence (and Why It Caps at 95%)
The confidence number on a ProbaBaby result is not copywriting. It starts at 60%, adds points for grandparents, childhood hair colour, ancestry and photos, and is clamped at 95% because genetics does not do certainty.