Category: medical

## The Outcome of Fetal Response and Learning to Prenatal Stimuli 

_Chairat Panthuraamphorn, Dawiep Dookchitra, and Manit Sanmaneechai_ 

Department of Obstetrics and Gynaecology, Hua Chiew Hospital, Bangkok, Thailand 

## **Keywords:** Fetal response; Learning; Prenatal stimuli 

**Abstract:** To study the fetal response to outside stimuli and assess the capacity of fetus’ memory and learning in various senses. The 120 pregnant mothers who attend prenatal enrichment unit in Hua Chiew Hospital were trained to practise the prenatal activity through out pregnancy. The activities consist of auditory, tactile and vestibular stimuli in various techniques. The clinical data and the evaluation sheet for analysis of fetal response and learning to prenatal activity were assessed in term of always, frequent, sometime, seldom and never response. 

The outcome of these samples demonstrated that 87.5% of experimental infants can recognize maternal voice and 70% recognize to prenatal music. They calm down significantly when giving a prenatal music, heart beat sound, rhythmic patting and rocking pattern which they ever received during in utero. This suggests that fetus can learn variety of sensory stimuli even before birth and these previous experiences they received in utero may influence postnatal learning and perception. Experimental infants have a capacity of turning to voice only at 4.6 days in average while the general population turn to voice at 3.2 month. This means that they have a faster auditory development and learning than general population. In addition, they can be conditioned by kicking back when they were pat in 64.9%. The results confirm our belief that fetus have a capacity of conditional learning. The study also showed better performance in relation between mother and child after participated the prenatal activity. These findings suggest that prenatal activity here may be introduced to routine prenatal care and may be an effective way to enhance mother and child attachment, as well as promote infant’s intelligent and emotional development.

## **Introduction** 

Newborns have been shown to respond to their environment from the first day of postnatal life. They can see, feel, hear and even recognize their mother’s voice. How and when does a baby learn these thing? Several researchs indicate that the learning may begins before birth. 

Hooker observed responses to tactile stimulation in human fetuses at the end of the 7th week gestational age, his stroking the lip of fetus with a light hair caused a reflex response. Elliott and Elliott report that the labyrinths acquire adult morphology and size during the 5th month gestational age. By 6 month the auditory apparatus is structurally mature, and fetus would be expected to respond to auditory stimuli. Also, some studies indicated that human fetus can be conditioned experimentally during the last two or three months of pregnancy. 

However, Most of the reports about prenatal learning focus on the fetal capacity of auditory learning more than the ability of other senses, while the basic sciencetific knowledge shows that the fetus developes in all sense during in utero. So, our purpose is to investigate that: 

1. Can the unborn child really learn during in utero, can they learn and respond to tactile stimuli, vestibular stimuli as well as auditory stimuli? 

2. Can human fetus recognize the previous experience during pregnancy and may the previous experience exert patent effect on postnatal learning and perception? 

3. Does the human fetus have a capacity of conditional learning? 

## **Material and Method** 

## _Subject_ 

The sample consisted of 120 infants whose mothers were applied the prenatal activity throught out the pregnancy period. The maternal characteristics are shown in Table 1. 

**Table 1.** Sample characteristics 



<!-- Start of picture text -->
|||||
|---|---|---|---|
|Maternal age|Gravid|
|Range|Percentage|Range|Percentage|
|21–25 year|13.9|1|64.5|
|26–30 year|37.6|2|19.4|
|31–35 year|38.7|3|6.4|
|36–40 year|6.5|4|1.1|
|40 up|3.2|Unknown|8.6|

<!-- End of picture text -->



<!-- Start of picture text -->
|||||
|---|---|---|---|
|Income|Educability|
|Bath per month|Percentage|Grade|Percentage|
|10,000|6.5|Undergraduate|29.8|
|10,000–20,000|24.7|Graduate|70.2|
|20,000–30,000|16.1|
|30,000 up|31.2|
|Unknown|21.5|

<!-- End of picture text -->

120 pregnant women were trained to practise the prenatal activity through out pregnancy. Type of prenatal activity and duration of practice. 

## _Measurement_ 

When the fetus moves arms, bends the eye brow, blinks eye or eye moves toward the stimuli, these indicate that fetus shows positive response to the stimuli. The fetus feels sleepy or calms down when received the previous stimuli indicates fetus’ capacity of memory and learning. The evaluation sheet for analysis of fetal response and learning to prenatal activity were collected in term of always, frequent, sometime, seldom and never response (only always and frequent response indicate that fetal can really response). 

The evaluation sheets are corresponding to our purpose: 

1. Canfetuslearnvarietyofsensesinutero?Fetuseswillbeevaluatedthatwhether they can recognize the maternal voice, prenatal music, rocking and patting pattern. 

2. May the prenatal experience influence the postnatal learning and perception? The clinical data was recorded that: 

   - How many days that infant can turn head to maternal voice. 

   - While the baby is crying, we will apply the prenatal music, heart beat sound, rhythmic patting pattern and rocking pattern and test whether each activity will calm down the infant or not. 

3. Does fetus have a capacity of conditional learning? The experimental pregnant woman will pat her abdomens everytime when fetus moves for a period of eight weeks, start from 28 week gestational age till 36 week. After that, during fetus awakes. Pat back to abdomen in order to see whether fetus will move in response or not. We recorded the number of response in term of percentage. 

## **Result** 

From Table 3, we found that the prenatal auditory activity was practised more than 3–4 / week in 83.3%, rhythmic patting 90.9% and 62.1% for vestibular activity. 

| Type of response | always | frequent | sometime | seldom | never |
| --- | --- | --- | --- | --- | --- |
|  | 62 (51.5%) | 44 (36.7%) | 13 (10.9%) | 1 (0.9%) |  |

**Fig. 1.** Recognition to maternal voice. 

| Type of response | always | frequent | sometime | seldom | never |
| --- | --- | --- | --- | --- | --- |
| Number and percentage of response | 36 (30%) | 48 (40%) | 31 (25.8%) | 2 (1.7%) | 3 (2.5%) |

**Fig. 2.** Recognition to prenatal music. 

| Metric | Value |
| --- | --- |
|  | 1.5 | 4.8 | 10.6 | 63.2 day |
| Percentile | 50 percentile |

**Fig. 3.** The ability of turning to maternal voice. 

The fetus’ recognition in Fig. 1 showed that 51.5% of the infants always recognize thier maternal voice and 36.7% recognize frequently. 30% of the infants always recognize thier prenatal music and 40% recognize frequently (Fig. 2). 

In Fig. 3, the experimental infants can recognize and turn to voice at 4.6 day of age in average while the Bangkok children can turn to voice at 3.2 month of age. In order to test the ability of learning previous experience during in utero, we found in Figs. 4–7 that: 

1. 27.5% of the infants always feel sleepy or calm down when they heard the prenatal music, 42.5% calm down frequently. (Fig. 4 – total response 27.5 + 42.5 = 70%) 

| Type of response | Number of response | Percentage of response |
| --- | --- | --- |
| always | 33 | 27.5% |
| frequent | 51 | 42.5% |
| sometime | 28 | 23.3% |
| seldom | 3 | 2.5% |
| never | 5 | 4.1% |

**Fig. 4.** Calming effect on previous prenatal music. 

| Type of response | Number | Percentage |
| --- | --- | --- |
| always | 27 | 22.5% |
| frequent | 50 | 41.6% |
| sometime | 30 | 25% |
| seldom | 5 | 4.1% |
| never | 8 | 6.6% |

**Fig. 5.** Calming effect on heart beat sound. 

2. 22.5% of the infants always feel sleepy or calm down when they heard the heart beat sound, 41.6% calm down frequently. (Fig. 5 – total response 22.5 + 41.6 = 64.1%) 

3. When the experimental infants was crying, the rhythmic patting pattern will be performed and we found that infants take 2.1 minute in average to stop crying, while the 100 control infants stopped crying with the same patting pattern in 4.6 minutes. (Fig. 6) 

4. 32.5% of experimental infants always calm down after giving the previous rocking pattern. 29.1% response frequently. (Fig. 7 – total response 32.5 + 29.1 = 61.6%) 

## TYPE 2 — CHARTS, GRAPHS & DATA VISUALIZATIONS

| Time (min) | 1 | 2.1 | 4.2 | 11.8 |
| --- | --- | --- | --- | --- |
| 50 percentile | | | | |

**Fig. 6.** Duration in response to rhythmic patting. 

| Type of response | Number | Percentage |
| --- | --- | --- |
| always | 39 | 32.5% |
| frequent | 35 | 29.1% |
| sometime | 25 | 20.8% |
| seldom | 6 | 5% |
| never | 15 | 12.5% |

**Fig. 7.** Calming effect on rocking chair. 

| Type of response | Number | Percentage |
| --- | --- | --- |
| always | 20 | 16.6% |
| frequent | 58 | 48.3% |
| sometime | 35 | 29.1% |
| seldom | 6 | 5% |
| never | 1 | 0.8% |

**Fig. 8.** Kick back response. (Conditional learning) 

The finding in Fig. 8 suggested that the experimental infants have a capacity of conditional learning. 16.6% of them always kick back in response, 48.3% kick back frequently. (Total response 16.6 + 48.3 = 64.9%) 

## **Discussion** 

Our previous study in 1994 on recognition to maternal voice and prenatal music of 24 experimental infants showed that 91.7% recognize to maternal voice and 87.5% recognize to prenatal music. But the findings on Figs. 1 and 2 in this paper indicate that 88.2% recognize maternal voice and 70% recognize to prenatal music. Because of the large amount of samples in this paper convince our belief that fetus can really perceive and learn during in utero. These result are also consistent with the studies of De Casper and Fifer (1980) that 16 newborns prefer there 

mother’s voice and Woodward (1992) investigated that 10 experimental infants can recognize previous prenatal music. 

Another point to be considered is that our both studies suggest that infants can significantly recognize maternal voice than prenatal music, this mean that maternal voice is one of the most effective stimuli that can influence infant’s perception and learning. It also means that infants prefer human’s voice than any other. 

The result on Fig. 3 suggest that the experimental infants can turn to voice 4.6 day while the Bangkok children turn to voice 3.2 month of age in average. This striking findings are consistent with our previous study on 24 infants which have a capacity of turning to voice 7 day in average. These results reconfirm our belief that maternal voice is a very powerful stimuli that infants can perceive and recognize earlier. The earlier of turning to voice also suggests that experimental infants have a faster auditory development than general population. 

In a series of papers, Salk (1960, 1961, 1962, 1965, 1973) reported that human infants exposed to the sound of an adult’s heart beat will cry less than infants not so exposed. A heart beat sound can produces long-term pacification in newborn. To check all of these possibilities, we investigate on a large number of 120 infants in Fig. 5 and found that 64.1% of experimental infants will response to heart beat sound by calming down and being sleepy. While 70% response to prenatal music with calming effect (Fig. 4). The capacity of prenatal memory on heart beat sound and prenatal music is now absolutely proven in this paper. And the prenatal experience can really influence postnatal learning and perception. Therefore, the important point to be stressed here is that the prenatal activity in this paper may be applied to routine prenatal care in order to promote the good emotional development after birth as well as create calming down effect to new born in clinical practice. 

The data from Figs. 6 and 7 showed us that after giving the rhythmic patting on experimental infants bottom, they will stop crying in 2.1 minute when compare to 4.6 minute in general population. 61.6% of experimental infants stop crying when rock them on the rocking chair. There findings confirm us that previous experience may influence postnatal perception and learning. This also suggest that fetus not only can perceive and learn auditory stimuli, but also learn tactile and vestibular stimuli as well. Therefore, rhythmic patting and rocking may be another consideration for routine practice of pregnant women in order to enhance the infants emotional development and make them easy to take care after birth. 

In Fig. 7 showed that the infants respond to rocking in the lower percentage than tactile and auditory activity. This due to the small amount of practice rocking shown in Table 3. However, the effective outcome from rocking will be found when practice more than 3–4 day in a week. 

Some studies suggested that fetus have a capacity of conditional learning at 28 week gestational age. The result of this paper reconfirm the finding of previous study that experimental infants can be conditioned by kicking back when patting in 64.9%. This prenatal tactile activity not only promote mother and child bonding, but also let the fetus learn to respond to outside stimuli. 

In conclusion, the effective outcome on 120 experimental infants here convinces our belief that fetus can learn not only auditory stimuli, but also tactile and vestibular stimuli. The previous experience that fetus received in utero may in- 

fluence postnatal learning and perception. Fetus also have a conditional learning even in utero. In addition, the prenatal activity mentioned in this paper should be introduced to routine prenatal care and could be an effective way to enhance mother and child attachment, as well as promote intelligent and growth to all children in this near future. 

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Question: In the Hua Chiew Hospital prenatal enrichment study of 120 infants, what share recognized maternal voice and prenatal music, how quickly did experimental infants turn to voice compared with Bangkok children, and what percentage showed conditional kick-back learning?
Answer: 87.5% of experimental infants recognized maternal voice and 70% recognized prenatal music. Experimental infants turned to voice at an average of 4.6 days of age, while Bangkok children turned to voice at 3.2 months. 64.9% of infants showed conditional learning by kicking back in response to patting (always or frequently).