First off, no I’m not pregnant.
I went to the doctor today and, upon hearing that I have three sons, he out-of-the-blue told me that “Couples with two sons are 15% likely to have a daughter and couples with three sons are only 10% likely.”
Geez. Thanks Doc.
Discuss, please. Does this statistic seem true to you?
I’ve heard this too but apparently it’s a myth. You’re only slightly less likely to have a girl after 3 boys.
http://www.in-gender.com/XYU/Odds/Gender_Odds.aspx
I have two boys and wound up pregnant at this time last year. I’d convinced myself it was another boy since we’d already had two and no one on my husband’s side of the family had any girls… I was shocked and it took three ultrasounds to convince me it was a girl this time (I still wasn’t convinced 100% until she actually arrived). Good luck with whatever you decide…from my experience, girls are WAY different than boys.
What your doctor told you is a complete myth. Your odds remain roughly (though not exactly) 50% with each child. It’s well explained here:
http://www.in-gender.com/XYU/Odds/Gender_Odds.aspx
Sorry guys, but biologically you have a 50% chance with each child, period. In a small sample size of a single family, obviously you see skewed ratios like a family of 4 boys, but that doesn’t change the overall chances.
I have heard that these statistics happen because men don’t produce exactly 50% X chromosome sperm and 50% Y. Some guys make more Xs and some guys make a higher percentage of Ys so if you already have three boys it’s likely that your husband produces more Y swimmers. So that’s why you have a lower chance of conceiving a girl next time. I didn’t hear this from a doctor though, just a dad of four boys so I haven’t fact-checked it!
@Emily, I just don’t think that 50/50 is true.
I have 3 boys. My SIL has 3 girls. My ex-roommate has 4 girls; another bloggy friend has 4 boys. We have a preschool family with 5 boys.
Of course I know some families with 2 of one and a baby of the other but it kinda feels like they “beat the odds”.
Speaking of beating the odds, @Citymama told me a great statistic about people with 2 of the same gender being that much more likely to have a third.
@Heather, re what @Citymama said: People with two of the same gender are more likely to have a third baby or wind up with a third of that same gender?
When we studied genetics in high school biology, one of the things we talked about was family makeup. You would think that if a family has 4 kids, the most likely configurations would be either all of one gender, or 50/50 (2 of each). As it turns out, the most likely configuration is 3 of 1 and 1 of the other. So if you’ve got 3 boys, chances are the next child will more likely be female, though that’s not 100%. And if you’ve got three girls, it might be a boy. My family makeup was me first (girl) then three boys, so…
Hoping you get what you want!
I read Rookie Moms every day, but as a scientist I feel compelled to comment for the first time! @Heather, there were over 4 million babies born in the US alone last year, so even in a “big” family with a sample size of 5, having all girls or all boys is easily achieved by chance. (And even though I’ve just railed against these examples as unscientific, yes, I am from a family of 2 girls and 1 boy, and so was my grad school roommate!).
I have two strictly anecdotal things to add, as in no research whatsoever has been done by me to verify what follows and I make no claims to be a scientist. (1) Environmental factors may affect the sperm and lean your chances one way or another. A friend of mine (she being one of two sisters in an Air Force family) told me that in USAF families it’s all girls because the G force does something to the sperm and only the XX combo makes it through the ride. In a related note, (2) babies all start off the embryonic stage as female and it is actually more difficult for the for the baby to become a male. It’s predetermined by the sperm but the sperm are all fairly delicate creatures and the heartier ones tend to be XX. Exposure to heavy chemicals, trauma, stresses, etc. can give dads the ability to only make girls (statistical finding, heard it on the radio long ago). So, I since my husband is not an astronaut nor a nuclear researcher, I figure I got two boys.
Like I said, I have no idea if this stuff is true but it does make you wonder.
I’m so glad I gut-checked this remark with you guys!
I pondering a 4th and would really love another girl (we have 1 girl, 2 boys) so I’m doing a little reading on the folk wisdom of making girls- things about timing conception with ovulation, vaginal pH and other fun things. While the genetic crap shoot is technically always 50-50, I wouldn’t be surprised if couples had certain predispositions to one sex or another based on their personal habits and chemistry. Not that I have any medical training. I’m a civil engineer. If you want a road, I’ve got that covered, though.
Genetics aren’t like tossing a coin- and sex isn’t equally distributed at birth (there are currently 105 males born for every 100 females born in the US). Females survive better, so they’re statistically dominant in the whole population.
Old thoughts on sex determination have discussed everything from the father’s diet and his underwear preference to the positions of conception. New thoughts from evolutionary biology suggest that the mother’s BMI/weight may act as a trigger- a heavier mom means a community that can sustain growth, so a girl is born to increase the community’s population while a slimmer mom might signal a need for more hunters/heavy laborers. None of these theories however has made us smack our foreheads and say “why didn’t I ever see that before?”
I suspect your doctor trusts and repeats that statistic because he’s seen parents disappointed to find their “this will be a girl” baby is actually a boy. 10% reminds us that we should really want a baby and not be trying to fulfill an abstract desire to diversify our baby portfolio. No person should have to start life as a disappointment.
Just to note that while it would be terrific to have another girl, I’d be tickled blue to have another boy as well. I agree with Adrienne- the decision to have another should be about the joy of having another. I had a friend who recently had a third and I got the impression things would have gotten ugly for a little while if he had turned out to be a girl. Made me very sad.
I’ve heard similar statistics before, but never read them in print or heard a source named. Just looking around, it doesn’t appear valid. Everyone in my family who has started out with two boys in a row has also had daughters. My mom – 2 boys, then 5 girls; my brother 2 boys, then 2 girls; my sister-in-law – 2 boys, then 1 girl.
I agree with Jen Vanya. From what I’ve read – and seen in my community of friends with kids – it’s usually a case of ‘fast sperm’ or ‘slow sperm’ in a family, resulting from genetics and environmental factors like Jen mentions. And timing. If you use natural or hormonal ways of “trying” to get pregnant (like an ovulation predictor kit), I think boys are more likely because of the timing. If fresh sperm meet a waiting egg, then you get a boy. If an egg pops into a pool of old sperm, you get a girl. Usually.
And to the ’50% chance of either sex’ folks, I am reminded of a Daily Show episode where some dude said, “There’s a 50/50 chance that the world will end tomorrow: either it will, or it won’t.” The interviewer said, “I don’t think that’s really how probability works.” LOL. Not really relevant for this conversation, I know, but I still get a giggle thinking about it.
Good luck trying for a girl Heather!
In my case, that’s completely FALSE! I too, had three boys…followed by three girls!
In my family:
After 2 boys, my grandma had a girl. After 2 boys, my aunt had a girl. After 3 boys, another aunt had twin girls. After 2 boys, my cousin had a girl. After 2 girls, another cousin had a boy. So, I’m not a doctor or statistician, but those numbers don’t jive with what I’ve seen
All I have is anecdotal…my husband’s generation in his family has now produced the 10th great-granddaughter with no boys. And we have a friend who hasn’t had a girl born in to the family in 3 generations – including natural triplet boys. I’m sure these are scientifically sound, but we weren’t surprised when I was pregnant with this our 2nd girl.
I only have an anecdote as well, but it’s an impressive one, if I do say so myself. My maternal grandmother had, in this order: 6 boys, 6 girls, 1 boy, 2 girls. For a total of 15 kids. But I guess if you’re going to have 15, you’re bound to defy probability at some point…
Anne-Marie’s comment made me laugh!
I have done alot of research in this regard – we have 2 girls and I have read everything I can find about this, in hopes of increasing the chances our third might be a boy (though I’d be happy either way!) It is NOT a coincidence that alot of families have children all of the same sex, this has to do with several factors:
- men don’t necessarily have 50/50 sperm – even if you undergo PGD for genetic pre-determination they make you sign a form that you understand no embryos of the desired sex may occur because some men can have high percentages of one gender of sperm. Whit sperm sorting technology, the sample of male to female sperm do not always come out evenly
- The pH levels in the vagina can contribute – male sperm thrive in acidic environmants, female sperm thrive in alkali ones. What you eat, your habits etc can effect the pH of your vagina thus encouraging one gender of sperm over the other
- The viscosity of your vaginal discharge can sway the results. Boy sperm swim fast, but are less resilient long term while girl sperm are larger, slower but more resilient to time and environmental stress. If your vaginal discharge is more watery, the boy sperm can swim quickly and efficiently to their goal. If your discharge is thicker, the boy sperm likely won’t make it through, and the slower girl sperm, still alive by the time they reach the goal, will win.
-and timing, as someone else has already stated, as per the ‘Shettles method’
So if you have a neutral pH, your husband has been proven to have 50/50 sperm, and your discharge is not too slippery not too sticky, THEN you have a 50/50 chance.
My grandmother had 6 children – girl, boy, girl, boy, girl, boy. She says the secret is to “Put the pattern under you” LOL