During the first trimester, the possibility of miscarriage (natural death of embryo or fetus) is at its highest. 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, though babies born at this time will likely experience serious health complications such as heart and respiratory problems and long-term intellectual and developmental disabilities. Prenatal care improves pregnancy outcomes. Nutrition during pregnancy is important to ensure healthy growth of the fetus. Prenatal care may also include avoiding drugs, tobacco smoking, and alcohol, taking regular exercise, having 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. In the ideal childbirth labor begins on its own when a woman is "at term". Babies born before 37 weeks are "preterm" and at higher risk of health problems such as cerebral palsy. Babies born between weeks 37 and 39 are considered "early term" while those born between weeks 39 and 41 are considered "full term". Babies born between weeks 41 and 42 weeks are considered "late term" while after 42 weeks they are considered "post term". Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons.About 213 million pregnancies occurred in 2012, of which, 190 million (89%) were in the developing world and 23 million (11%) were in the developed world.
Alternatively there are mobile apps, which essentially always give consistent estimations compared to each other and correct for leap year, while pregnancy wheels made of paper can differ from each other by 7 days and generally do not correct for leap year.Furthermore, actual childbirth has only a certain probability of occurring within the limits of the estimated due date. A study of singleton live births came to the result that childbirth has a standard deviation of 14 days when gestational age is estimated by first trimester ultrasound, and 16 days when estimated directly by last menstrual period. Physiology
Capacity
Fertility and fecundity are the respective capacities to fertilize and establish a clinical pregnancy and have a live birth. Infertility is an impaired ability to establish a clinical pregnancy and sterility is the permanent inability to establish a clinical pregnancy.The capacity for pregnancy depends on the reproductive system, its development and its variation, as well as on the condition of a person. Women as well as intersex and transgender people who have a functioning female reproductive system are capable of pregnancy. In some cases, someone might be able to produce fertilizable eggs, but might not have a womb or none that can sufficiently gestate, in which case they might find surrogacy. Initiation
Through an interplay of hormones that includes follicle stimulating hormone that stimulates folliculogenesis and oogenesis creates a mature egg cell, the female gamete. Fertilization is the event where the egg cell fuses with the male gamete, spermatozoon.