Pregnancy is typically divided into three trimesters. The first trimester is from week one through 12 and includes conception, which is when the sperm fertilizes the egg. The fertilized egg then travels down the fallopian tube and attaches to the inside of the uterus, where it begins to form the embryo and placenta. During the first trimester, the possibility of miscarriage (natural death of embryo or fetus) is at its highest.
The second trimester is from week 13 through 28.Around the middle of the second trimester, movement of the fetus may be felt At 28 weeks, more than 90% of babies can survive outside of the uterus if provided with high-quality medical care. The third trimester is from 29 weeks through 40 weeks.
Prenatal care improves pregnancy outcomes. Prenatal care may include taking extra folic acid, avoiding drugs and alcohol, regular exercise, blood tests, and regular physical examinations. Complications of pregnancy may include disorders of high blood pressure, gestational diabetes, iron-deficiency anemia, and severe nausea and vomiting among others. In the ideal childbirth labor begins on its own when a woman is “at term”.
Pregnancy is considered at full term when gestation has lasted 39 to 41 weeks. After 41 weeks, it is known as late term and after 42 weeks post term. Babies born before 39 weeks are considered early term while those before 37 weeks are preterm. Preterm babies are at higher risk of health problems such as cerebral palsy. Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons.
The sperm and the egg cell, which has been released from one of the female’s two ovaries, unite in one of the two fallopian tubes. The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete. Cell division begins approximately 24 to 36 hours after the female and male cells unite. Cell division continues at a rapid rate and the cells then develop into what is known as a blastocyst. The blastocyst arrives at the uterus and attaches to the uterine wall, a process known as implantation.