Blog
Practical, evidence-based reading on pregnancy, postpartum, and the science behind ProbaBaby's predictions.
Twin Pregnancy Weight Gain: The IOM Targets by BMI
Twin pregnancy weight gain has its own targets, and they are not the singleton numbers doubled. Here are the IOM 2009 provisional ranges by pre-pregnancy BMI, why there is no range at all for underweight women, when in the pregnancy the gain actually matters, and what the research since 2009 shows about gaining below or above them.
Understanding Baby Growth Charts: WHO Percentiles Explained
A percentile is a ranking, not a grade. Here's what baby growth chart percentiles really mean, why the US uses WHO curves under two years, why the shape of the line matters more than any single dot, and how prematurity changes the maths.
Wake Windows by Age: A Complete Reference (0–12 Months)
Wake windows are a parenting convention, not a clinical measurement — but the sleep totals underneath them are published and checkable. Here is the age-by-age table, where the numbers come from, the sleepy cues that beat a timer, and what actually changes around four months.
When Are Twins Born? Twin Delivery Timing by Chorionicity (34–38 Weeks)
Planned twin birth falls between 34 and 38 weeks in UK and US guidance, and the exact week depends on chorionicity: UK guidance offers planned birth at 37 weeks for twins with a placenta each, 36 weeks when they share a placenta, and 32 to 33 weeks when they share a sac. Around 6 in 10 twins arrive before 37 weeks regardless.
When Did I Conceive? Reverse Due Date and Conception Date Explained
Subtract 266 days from your estimated due date and you have your most likely conception date. Here is why that number is 266 and not 280, why conception means ovulation rather than the night you remember, and how wide the honest answer really is.
When Does Your Period Return After Birth? (Breastfeeding vs Formula)
Your first period after birth can arrive at six weeks or well past a year, and feeding pattern is the biggest reason for the gap. Here is what sets the timing, how to tell lochia from a real period, and why ovulation restarts before any bleeding warns you.
When to Start Solids: Readiness Signs, First Foods and How to Log Them
Guidelines put solids at around 6 months, but the calendar is only half the answer. Here are the readiness signs that actually count, safe first foods, how allergen introduction works, and what is worth writing down.
Your Twin Due Date Is Really Week 37: How Twin Due Dates Work
A twin due date is calculated the same way a singleton's is — last period plus 280 days. What changes is the week your team plans delivery for: 37 weeks for twins with a placenta each, 36 for twins sharing one, earlier again for mo/mo twins. Here is where both numbers come from.