A nurse is preparing to assess a newborn who is postmature. Which of the following findings should the nurse expect? (Select all that apply.)
A Abundant lanugo
B Vernix in the folds and creases
C Short, soft fingernails
D Cracked, peeling skin
E Positive Moro reflex
The Correct Answer and Explanation is:
When assessing a postmature newborn, several specific findings can be expected. A postmature infant is one who is born after 42 weeks of gestation. These infants exhibit distinct physical characteristics due to prolonged exposure to the uterine environment. Let’s examine the options provided:
A. Abundant lanugo
B. Vernix in the folds and creases
C. Short, soft fingernails
D. Cracked, peeling skin
E. Positive Moro reflex
Correct Answers: D and E
Explanation
- Cracked, Peeling Skin (D): Postmature infants often exhibit cracked and peeling skin. This is due to the prolonged exposure to amniotic fluid which, over time, causes the skin to become dry and lose its natural protective coating. The vernix caseosa, a thick, cheese-like substance covering the skin of the fetus, diminishes with gestational age. In postmature infants, the absence or minimal amount of vernix leads to more exposure of the skin, making it more prone to peeling and cracking.
- Positive Moro Reflex (E): The Moro reflex, also known as the startle reflex, is a normal reflex present in newborns. It is characterized by the infant’s response to a sudden loss of support or a loud noise, which involves spreading the arms, pulling them back in, and often crying. A positive Moro reflex indicates that the central nervous system is functioning normally. This reflex should be present in postmature infants as well, unless there are other complications affecting neurological function.
Why Other Options Are Incorrect
- Abundant Lanugo (A): Lanugo is the fine, downy hair that covers the fetus in utero. In postmature infants, lanugo is typically minimal or absent as it tends to shed as the pregnancy progresses towards term.
- Vernix in the Folds and Creases (B): Vernix caseosa is usually less abundant in postmature infants. By this stage, much of it has been absorbed or worn off, so it is uncommon to see significant amounts of vernix in the folds and creases.
- Short, Soft Fingernails (C): Postmature infants usually have long, well-developed fingernails that may even extend beyond the fingertips. They are not typically short and soft but rather may require trimming shortly after birth.
In summary, when assessing a postmature newborn, expect findings like cracked, peeling skin and a positive Moro reflex, while abundant lanugo, significant vernix, and short, soft fingernails are not characteristic of postmaturity.