Gestational Week

Question 1

The length of the embryo is about 0.75 cm; weight is about 400 mg.

The spinal cord is formed and fused at the
midpoint.

The head is large in proportion and represents about one third of the entire structure.

Answer 1

4th

Question 2

The rudimentary heart appears as a prominent bulge on the anterior surface

Arms and legs are bud-like structures; rudimentary eyes, ears, and nose are discernible.

Answer 2

4th

Question 3

The length of the fetus is about 2.5 cm (1 in.); weight is about 20 g.

Organogenesis is complete

The heart, with a septum and valves, beats rhythmically.

Answer 3

8th

Question 4

Facial features are definitely discernible; arms and legs have developed

External genitalia are forming, but sex is not yet distinguishable by simple observation.

The abdomen bulges forward because the fetal intestine is growing so rapidly

Answer 4

8th

Question 5

The length of the fetus is 7 to 8 cm; weight is about 45 g.

Nail beds are forming on fingers and toes.

Spontaneous movements are possible, although they are usually too faint to felt by the mother.

Some reflexes, such as the Babinski reflex, are present.

Answer 5

12th (first trimester)

Question 6

Bone ossification centers begin to form.

Tooth buds are present.

Sex is distinguishable on outward appearance.

Urine secretion begins but may not yet be evident in amniotic fluid.

The heartbeat is audible through Doppler technology.

Answer 6

12th (first tri)

Question 7

The length of the fetus is 10 to 17 cm; weight is 55 to 120 g.

Fetal heart sounds are audible by an ordinary stethoscope.

Lanugo is well formed.

Answer 7

16th

Question 8

Both the liver and pancreas are functioning

The fetus actively swallows amniotic fluid, demonstrating an intact but uncoordinated swallowing reflex; urine is present in amniotic fluid.

Sex can be determined by ultrasonography.

Answer 8

16th

Question 9

The length of the fetus is 25 cm; weight is
223 g.

Spontaneous fetal movements can be sensed by the mother

Antibody production is possible.

Hair, including eyebrows, forms on the head; vernix caseosa begins to cover the skin.

Meconium is present in the upper intestine.

Answer 9

20th

Question 10

Brown fat, a special fat that aids in temperature regulation, begins to form behind the kidneys, sternum, and posterior neck.

Passive antibody transfer from mother to fetus begins.

Definite sleeping and activity patterns are distinguishable as the fetus develops

biorhythms that will guide sleep/wake patterns throughout life.

Answer 10

20th

Question 11

The length of the fetus is 28 to 36 cm; weight is 550 g.

Meconium is present as far as the rectum.

Active production of lung surfactant begins.

Eyelids, previously fused since the 12th week, now open; pupils react to light.

Answer 11

24th(second trimester)

Question 12

Hearing can be demonstrated by response to sudden sound.

When fetuses reach 24 weeks, or 500 to 600 g, they have achieved a practical low-end age of viability if they are cared for after birth in a modern intensive care nursery.

Answer 12

24th (second tri)

Question 13

The length of the fetus is 35 to 38 cm; weight is 1,200 g.

Lung alveoli are almost mature; surfactant can be demonstrated in amniotic fluid.

Answer 13

28th

Question 14

Testes begin to descend into the scrotal sac from the lower abdominal cavity.

The blood vessels of the retina are formed but thin and extremely susceptible to damage from high oxygen concentrations (an important consideration when caring for preterm infants who need oxygen).

Answer 14

28th

Question 15

The length of the fetus is 38 to 43 cm: weight is 1.600 g.

Subcutaneous fat begins to be deposited in the former stringy. “little old man” appearance is lost).

Fetus responds by morement to sounds outside the mother’s body.

Answer 15

32nd

Question 16

An active Moro reflex is present.

Iron stores. which provide iron for the time during which the neonate will ingest only breast milk after birth, are beginning to be

Fingernails reach the end of fingertips.

Answer 16

32nd

Question 17

The length of the fetus is 42 to 48 cm; weight is 1,800 to 2,700 g (5 to 6 1b).

Body stores of glycogen, iron, carbohydrate, and calcium are deposited

Additional amounts of subcutaneous fat are deposited

Answer 17

36th

Question 18

Sole of the foot has only one or two crisscross creases compared with a full crisscross pattern evident at term.

Amount of lanugo begins to diminish.

Most fetuses turn into a vertex (head down) presentation during this month

Answer 18

36th

Question 19

The length of the fetus is 48 to 52 cm (crown to rump, 35 to 37 cm); weight is 3,000 g (7 to 7.516).

Fetus kicks actively, sometimes hard enough to cause the mother considerable discomfort.

Fetal hemoglobin begins its conversion to adult hemoglobin.

Vernix caseosa starts to decrease after the infant reaches 37 weeks gestation and may be more apparent in the creases than the covering of the body as the infant approaches 40 weeks or more gestational age.

Answer 19

40th(third trimester)

Question 20

Fingernails extend over the fingertips.

Creases on the soles of the feet cover at least two thirds of the surface.

In primiparas (ie, women having their first baby), the fetus often sinks into the birth canal during the last 2 weeks of pregnancy. giving the mother a feeling the load she is carrying is less. This event, termed lightening, is a fetal announcement that the fetus is in a ready position and birth is nearing.

Answer 20

40th(third tri)