Lelaiwa Consulting Service Center
You are here: Home > News > industry news
Does the shape of pregnancy sac distinguish gender?
Source: LelaiwaPublished: 2025-12-15
This article is compiled and published by the lelaiwa team. Unauthorized reproduction is prohibited. For ongoing updates on fertility preparation, IVF, and overseas or U.S. childbirth, scan the consultant's QR code on the right to get free updates, or contact lelaiwa for free consultation anytime.

"Where is your B super order? Lend it to me to see the shape of the pregnancy sac! The round one is a girl, and the long one is definitely a boy."Recently, many expectant mothers have circulated such" gender judgment secrets "in their social circles. Repeatedly comparing freshly released B-ultrasound scans and "betting" on the sex of the fetus with pregnant mothers in the group has become a daily routine for some people during pregnancy.
“”.Today, let's ask obstetrics and gynecology experts to explain this matter thoroughly: It is sheer nonsense to judge the gender of a fetus through the shape of the pregnancy sac!
1. The origin of the rumor. What exactly are the contents of the widely spread “secret rules for making judgments” on the internet?
,,“”,,“”,.The most widely circulated claims currently fall into two categories:
The first category is the "morphological visualization method": claiming that the pregnancy sac looks like long strips such as eggplant or cucumber, and it is likely that it is a boy; if the pregnancy sac is round or oval, it may be a girl. The other type is the "data comparison method": it emphasizes looking at the three data of the gestational sac on the B-ultrasound list (only before 8 weeks). If two of the sides are more than twice the length of the third side, it is a standard male treasure; If the three sides are similar in numerical values or the three sides form an arithmetic sequence, it is a female treasure.
Some even post “Examples: A certain pregnant woman had a gestational sac measuring 4.0×3.8×1.9 cm, and she gave birth to a boy” or “My gestational sac measured 2.9×1.8×1.8 cm, and it was confirmed to be a girl.” These kinds of statements try to present rumors as “real experiences”, thereby making many people less cautious about them.
Second, the doctor refuted these rumors: The shape and gender of the gestational sac have nothing to do with anything related to money at all!
“,.”The obstetrician and gynecologist of the Maternal and Child Health Hospital of Shanxi Province bluntly said that there is no scientific basis for this statement.
:?It is the "protective shell" of embryos in early pregnancy. It appears as a cystic structure under ultrasound. Its main role is to provide a stable environment for embryonic development. Its shape is only related to the objective conditions of embryonic development and has no relationship with the gender of the fetus.
:“,,.The shape of the gestational sac on a B-ultrasound scan often depends on the angle at which the doctor operates the probe and the scanning section. If the same gestational sac is photographed at a different angle, the shape may be completely different."
,,,,.For example, in the early stages of pregnancy, the gestational sac is not fully developed and stable, and may be long and narrow in shape; as the gestational age increases, it will gradually become full and round. Each woman's uterus is different in size and shape, and the pregnancy sac is also "shaped" with the uterus, which has nothing to do with the gender of the fetus.
Thirdly, is it really possible to determine the gender of a fetus through medical methods?
:,?The answer is yes, but the use of this type of technology has extremely strict restrictions and is by no means a "tool" used to satisfy individual gender preferences.
Currently, the most accurate method for determining the gender of a fetus in medicine is through third-generation in vitro fertilization technology. This technique is used for genetic screening before the embryo is implanted into the mother’s uterus. By extracting a small amount of embryonic cells for analysis, it is possible to accurately determine the type of sex chromosomes, thereby knowing the gender of the fetus.
,,XY,,.Cui Yuqian, deputy chief physician of Qilu Hospital of Shandong University, once explained: "The core value of the third-generation IVF technology is to screen out embryos carrying pathogenic genes and block the transmission of sex-linked genetic diseases such as hemophilia and Duchenne muscular dystrophy. Instead of satisfying gender preference."
<>,,,.For healthy families who have no medical indications and simply want to choose the gender of the fetus, formal medical institutions in China cannot provide relevant services. However, if such families have needs, they can understand the legal channels in countries and regions with relatively loose policies such as the United States and Thailand. Wherever you choose, it is recommended to fully understand local laws, regulations and ethical norms and rationally treat the gender issue of the fetus.
:,.Whether it is a boy or a girl, it is a unique treasure. Stop worrying about these rumors that have no scientific basis. Regular prenatal check-ups and following doctor's advice are better responsible for yourself and your baby ~


For more on fertility preparation, second/third-generation IVF, and overseas, U.S., Thailand, Malaysia, America or Cambodia IVF, scan the QR code on the right or call lelaiwa's hotline+852 6145 8043!
online consultation
ONLINE CONSULTATION
LINE QR code
Email an advisor