Day 72 of 280, first trimester
You are 10 weeks and 2 days
Boy or girl? Big changes are happening that let your baby's sex organs develop.
208 days until your due date
Hormones are shaping your baby's development, and the ovaries or testes are starting to form. The testes will gradually descend, but their structure won't be complete until puberty. The ovaries will produce eggs, but these stay at an early stage of development.
A tiny genital tube forms the external genitals, but both sexes still look the same, which isn't surprising since the phallus is only 0.09 in (2.5 mm) long.
The bladder and rectum have now separated. The kidneys take a while to develop fully: two buds (ureteric buds) grow up from the bladder, one on each side, and form the ureters, the tubes that carry urine from the kidneys to the bladder. Each bud has to fuse with the kidney tissue in the pelvis, and as the buds grow upward, the early kidneys move up from the pelvis into the abdomen.
Ask a Doctor
I have hay fever. Can I take antihistamines?
The possible effects of antihistamines in pregnancy aren't known, so it's best not to take them. But if your symptoms are very severe, see your doctor, because one prescription antihistamine can be taken in pregnancy.
Focus on
Twins: A shared support system
Nonidentical twins always have separate amniotic sacs and a placenta each. Identical twins (from one fertilized egg) may share a placenta and/or amniotic sac, surrounded by a single membrane called the chorion. These "monochorionic" twins need closer monitoring, and the arrangement can be checked on an ultrasound scan.
When twins share a placenta, a blood vessel connects them directly. This can give one twin too much blood, which can cause heart problems, while the other gets too little and doesn't grow properly. Called twin-to-twin transfusion, it happens in about 10–15 percent of monochorionic pregnancies, and one baby ends up bigger than the other. It can sometimes be corrected by draining amniotic fluid from around the twin with more blood, or by using a laser to seal off some placental blood vessels. An early delivery may be needed.
Appointments and key dates around now
- Booking appointmentUsually between 8 and 12 weeks
Read the full 10 weeks pregnant guide
This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.